The Weed's News Digest

The Weed's News email digest contains a summary of activity for the time period August 26, 2011 through April 23, 2014.
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The Weed's News Articles

What should I do about my pasture weeds?

Zheljana Peric / WeedsNews4843 / April 15, 2014 / 9:35:18 PM EST / 0 Comments
[On Pasture 24 March 2014 by Kathy Voth] — Back in the Spring of 2010, the Agriculture Research Service (ARS) in Miles City, Montana put out a press release announcing an online calculator that could tell producers how many more cattle they could raise if they were able to eliminate one or two widespread invasive plants. Matt Rinella, the rangeland ecologist who developed the tool, used it to estimate that ranchers in a 17-state region could raise 200,000 more cows a year and save tens of millions of dollars if leafy spurge were eliminated. Of course how to eliminate leafy spurge, or any other weed, is a problem we’ve yet to solve. As many of you already know, I developed a method to teach cows (or whatever livestock you raise) to eat weeds. So when I saw the ARS announcement I looked at Matt Rinella’s results from a completely different perspective. If cattle can eat leafy spurge (and I have actually trained cattle to eat this plant), that means that there is enough forage available right now for 200,000 more cattle. If we went straight to grazing leafy spurge instead of trying to eliminate it, we’d save even more than the tens of millions estimated by Rinella. [Photo caption: This is an example of the progress trained heifers made on reducing leafy spurge in pasture at Grant-Kohrs Ranch National Historic Site in Deer Lodge Montana. Pictures were taken in early August of 2005. After the fence was taken down and cattle had access to a mown hayfield, they returned to this pasture on their own and finished off the leafy spurge.] Read the full article (click here). Comment

Herbicides and pesticides can cause cancer - so why does Cancer Research UK ignore them?

Zheljana Peric / WeedsNews4840 / April 15, 2014 / 9:05:01 PM EST / 0 Comments
[Ecologist 03 April 2014 by Georgina Downs] — Cancer Research UK's slogan is 'Let's beat cancer sooner'. But Georgina Downs wonders why it ignores the role of pesticides sprayed on crop fields - which is a recognised cause of cancer - and why it has spent over £750 million since 2007 on paying its employees. It is hard to think of a day when cancer is not in the headlines such is its increasing prevalence in one form or another in all our lives.However, over the last couple of weeks there has been a significant increase in mass media coverage of the disease as a result of the 'no make up selfie' campaign started by someone on social media. Although the campaign was seemingly not initially connected to any particular charitable activity, it was soon 'jumped on' by Cancer Research UK (CRUK).1 CRUK certainly acted fast to ensure it would get maximum public donations and sure enough in the space of not even a week CRUK had received a staggering £8 million. If I really thought that this increase in funds would help "beat cancer sooner" (in the words of CRUK's current slogan)2 then I would be fully supportive. After all, I myself have witnessed first-hand the devastating impact of cancer from the loss of some of my own family members (including my Auntie Barbara, the first and only British female Concorde pilot)3, close friends - and some of the rural residents that had contacted the campaign I run on the adverse health impacts of agricultural pesticides. Continue reading ….

Biological control of Rumex obtusifolius and Rumex crispus by goat grazing

Zheljana Peric / WeedsNews4838 / April 15, 2014 / 8:39:57 PM EST / 0 Comments
Abstract: Rumex obtusifolius and Rumex crispus are problematic grassland weedy species, particularly under conditions of organic farming. They are avoided by cattle and horses, but they can be grazed by goats. The aim of this study was to investigate the effectiveness of continuous goat grazing of moderate intensity on R. obtusifolius and R. crispus control. In 2008, 40 seedlings of each species were transplanted into pasture that was grazed by goats (crossbreed Czech white × Czech brown) on the target sward height of 7–10 cm. The number of leaves, proportion of grazed leaves and mortality of plants were monitored over the following 4 years. The number of leaves per plant was higher for R. obtusifolius than for R. crispus. The maximal number of leaves per plant of R. obtusifolius and R. crispus was 10 and 5, respectively. The proportion of grazed leaves was generally higher for R. obtusifolius than for R. crispus and ranged from 10% to 80%. No fertile plant was recorded during the experiment, as goat grazing totally prevented the flowering of both species. The level of mortality of the plants at the start of the fourth grazing season was 70% and 87% for R. obtusifolius and R. crispus, respectively, and no plant survived the fourth grazing season. It was concluded that continuous goat grazing of a moderate intensity that is carried out over 4 years seems to be an effective method for the non-chemical control of R. obtusifolius and R. crispus in grassland. [Michal Hejcman, Lukáš Strnad, Pavla Hejcmanová & Vilém Pavlů (2014). Biological control of Rumex obtusifolius and Rumex crispus by goat grazing. Weed Biology and Management, online 9 April 2014.] Comment

Successful biological control of tropical soda apple (Solanales: Solanaceae) in Florida: A review of key program components

Zheljana Peric / WeedsNews4835 / April 4, 2014 / 10:34:22 PM EST / 0 Comments
Abstract: Tropical soda apple (Solanum viarum Dunal) (Solanaceae) is a small shrub native to South America that is invasive in pastures and conservation areas across Florida. Dense patches of tropical soda apple not only reduce cattle stocking rates and limit their movement, but also serve as reservoirs for pests of solanaceous crops. A classical biological control program was initiated in 1994 with exploration for natural enemies of tropical soda apple in Argentina, Brazil, and Paraguay. Host specificity tests conducted under laboratory and field conditions demonstrated that the leaf feeding beetle Gratiana boliviana Dunal (Coleoptera: Chrysomelidae) was a specialist herbivore that completes development only on the target weed. After obtaining appropriate permits, field releases of G. boliviana were initiated in Florida in May of 2003. Larvae and adults of G. boliviana feed on tropical soda apple leaves and may completely defoliate their host plants, resulting in reduced growth and fruit production. Mass rearing facilities for the beetle were established in northern, central and southern Florida, and adults were either hand-carried or transported to release sites by overnight courier. From 2003 to 2011, a total of 250,723 beetles were released and they became established throughout Florida, however, their impact is more noticeable in regions below latitude 29 °N. Reductions of tropical soda apple densities caused by damage by the beetle were visible 2-3 yr after initial release, or in some cases, within a few months. Various methods of technology transfer were used to inform the public, land owners, funding agencies and scientists about the biological control program, including articles in trade magazines, extension publications, websites, videos, field days and scientific publications. The project was successful because of the coordinated efforts of personnel from federal, state and county agencies.[R. Diaz, V. Manrique, K. Hibbard, A. Fox, A. Roda, D. Gandolfo, F. Mckay, J. Medal, S. Hight and W. A. Overholt (2014). Successful biological control of tropical soda apple (Solanales: Solanaceae) in Florida: A review of key program components. Florida Entomologist, 97(1):179-190] Comment

Glyphosate accumulates in Roundup Ready GM soybeans

Zheljana Peric / WeedsNews4832 / April 4, 2014 / 5:45:07 PM EST / 0 Comments
Abstract: This article describes the nutrient and elemental composition, including residues of herbicides and pesticides, of 31 soybean batches from Iowa, USA. The soy samples were grouped into three different categories: (i) genetically modified, glyphosate-tolerant soy (GM-soy); (ii) unmodified soy cultivated using a conventional “chemical” cultivation regime; and (iii) unmodified soy cultivated using an organic cultivation regime. Organic soybeans showed the healthiest nutritional profile with more sugars, such as glucose, fructose, sucrose and maltose, significantly more total protein, zinc and less fibre than both conventional and GM-soy. Organic soybeans also contained less total saturated fat and total omega-6 fatty acids than both conventional and GM-soy. GM-soy contained high residues of glyphosate and AMPA (mean 3.3 and 5.7 mg/kg, respectively). Conventional and organic soybean batches contained none of these agrochemicals. Using 35 different nutritional and elemental variables to characterise each soy sample, we were able to discriminate GM, conventional and organic soybeans without exception, demonstrating “substantial non-equivalence” in compositional characteristics for ‘ready-to-market’ soybeans.[T. Bøhn, M. Cuhra,T. Traavik, M. Sanden, J. Fagam & R. Primicerio (2014). Compositional differences in soybeans on the market: Glyphosate accumulates in Roundup Ready GM soybeans. Food Chemistry, 153, 207–215] Comment

Presence of glyphosate residues in animals and humans

Zheljana Peric / WeedsNews4826 / March 19, 2014 / 10:24:01 PM EST / 0 Comments
Abstract: In the present study glyphosate residues were tested in urine and different organs of dairy cows as well as in urine of hares, rabbits and humans using ELISA and Gas Chromatography-Mass Spectroscopy (GC-MS). The correlation coefficients between ELISA and GC-MS were 0.96, 0.87, 0.97and 0.96 for cattle, human, and rabbit urine and organs, respectively. The recovery rate of glyphosate in spiked meat using ELISA was 91%. Glyphosate excretion in German dairy cows was significantly lower than Danish cows. Cows kept in genetically modified free area had significantly lower glyphosate concentrations in urine than conventional husbandry cows. Also glyphosate was detected in different organs of slaughtered cows as intestine, liver, muscles, spleen and kidney. Fattening rabbits showed significantly higher glyphosate residues in urine than hares. Moreover, glyphosate was significantly higher in urine of humans with conventional feeding. Furthermore, chronically ill humans showed significantly higher glyphosate residues in urine than healthy population. The presence of glyphosate residues in both humans and animals could haul the entire population towards numerous health hazards, studying the impact of glyphosate residues on health is warranted and the global regulations for the use of glyphosate may have to be re-evaluated. [Krüger M, Schledorn P, Schrödl W, Hoppe HW, Lutz W, et al. (2014). Detection of Glyphosate Residues in Animals and Humans. J Environ Anal Toxicol, 4: 210. doi: 10.4172/2161-0525.1000210] Comment

When the fear of plants is dangerous

Zheljana Peric / WeedsNews4820 / March 16, 2014 / 9:19:47 PM EST / 0 Comments
[The Weed's Network 16 March 2014 by Zheljana Peric] — Herbicide pollution has become “safe” even though dangerous. When we use conventional weeding techniques that rely on herbicides, we are agreeing to both the risks and the background assumptions that underlie the normalcy of these risks (Carolan 2008). Rather than reduce the risks associated with herbicide pollution, these days we talk of “food safety” or “compliance within maximum residue limits”. Governments and their regulatory agents have identified the human health and environmental hazards of herbicides, but they currently make very little effort to reduce or eliminate them. The normalisation of herbicide pollution is therefore not based on what would provide us with genuine safety, nor do regulators err on the side of safety when there is any uncertainty over a particular herbicide’s impacts. As Hoffman (2013) notes, by not taking a precautionary approach, the regulators and users of herbicides are “risk takers”. Worse, the risks we are taking with herbicides cannot be contained or limited to the decision-makers and users of herbicides. There are collateral victims to be considered in the so-called “war on weeds”. For example, herbicides are found in the food we eat and the air we breathe. They are in our waterways and are affecting the lives of those beings that live in them. We are all being forced to accept the risks of deliberate acts of herbicide pollution. The risk-taking behaviour associated with herbicides is therefore paradoxical – the more we seek safety through poisoning life, the more dangers we create. Read more ….

USA's EPA seeks tougher safety standards for farmworkers

Zheljana Peric / WeedsNews4818 / March 14, 2014 / 11:42:37 PM EST / 0 Comments
WASHINGTON (AP) — The Environmental Protection Agency on Thursday proposed strengthening 20-year-old standards aimed at protecting farmworkers from toxic pesticides. "The current rule is not working the way it should," said Jim Jones, head of the agency's Office of Chemical Safety and Pollution Prevention. The changes would bar almost anyone 16 and younger from handling the most toxic pesticides and require no-entry zones around fields to protect workers from drift and fumes. Farms would also have to post no-entry signs to prohibit workers from entering fields until pesticide residues declined. Farms would also have to provide annual training sessions on pesticide risk to workers, including how to protect their families when they return home with clothes and shoes potentially laced with pesticides. Now, farmworkers receive training once every five years. Farms staffed with family members would continue to be exempt. The EPA says that between 1,200 and 1,400 cases of pesticide exposure are reported each year at farms, nurseries and other agricultural operations covered by the current standards. But the EPA says that 20 to 90 percent more cases are not being reported. Farmworkers are unique in that many of the workplace protection standards issued by the Occupational Safety and Health Administration for other industries do not apply to them. Many farmworkers are migrants who move from farm to farm, making it difficult to track health problems from pesticide exposure that can develop overtime. "For far too long, this essential labor force has been treated as second class," said Amy Liebman, the director of environmental and occupational health for the Migrant Clinicians Network, an organization that focuses on migrant health care. Liebman said the group was pleased with EPA's proposal but would like to have seen it include more frequent training, additional protections for workers applying the pesticides, such as medical monitoring, and protections for whistleblowers who file complaints. Comment

Hazard and risk of herbicides for marine microalgae

Zheljana Peric / WeedsNews4816 / March 14, 2014 / 10:50:37 PM EST / 0 Comments
Abstract: Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol®1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally.[Sascha B. Sjollema, Gema MartínezGarcía, Harm G. van der Geest, Michiel H.S. Kraak, Petra Booij, A. Dick Vethaak & Wim Admiraal (2014). Hazard and risk of herbicides for marine microalgae. Environmental Pollution, 187, 106–111] Comment

Sri Lanka bans glyphosate weedicide responsible for kidney disease

Zheljana Peric / WeedsNews4808 / March 14, 2014 / 7:37:03 PM EST / 0 Comments
[ColomboPage 12 March 2014] COLOMBO: Sri Lanka has banned the sale of Monsanto's "Round Up" glyphosate weedicide after a study found that the weedicide is responsible for the increasing number of chronic kidney disease patients. Minister off Special Projects S.M. Chandrasena said the decision to ban Glyphosate sales in the country has been taken on a directive of the President Mahinda Rajapaksa. Addressing a media briefing, the Minister said several programs have been implemented to prevent the high occurrence of kidney disease among the farming community. A new study published in the International Journal of Environmental Research and Public Health found a link between the weedicide known as Roundup and the fatal Chronic Kidney Disease of Unknown origin (CKDu) affecting mostly, the rice farmers in Sri Lanka and several other countries. The study found that while the weedicide itself is not nephrotoxic, when it combines with hard ground water containing metals such as cadmium and arsenic, either naturally present in the soil or added through fertilizer, glyphosate becomes extremely toxic to the kidney. In recent years a significant increase in the number of CKD patients has been observed in some parts of the country, especially in North Central, North Western, Uva and Eastern Provinces. According to the Minister a national program to prevent the kidney disease will be launched next Friday. The program will encourage the Sri Lankan farmers to produce and use organic fertilizer. Comment

Feasibility of paper mulches in crop production — a review

Zheljana Peric / WeedsNews4805 / March 13, 2014 / 10:31:08 PM EST / 0 Comments
Abstract: Mulching has become an important practice in modern field production. Plastics are the most widespread mulching materials, and especially black polyethylene is used almost everywhere due to its low price and proved positive results in production. Together with its still growing popularity, there is increasing concern about the environmental effects of using such vast amounts of plastics in agriculture without solutions for sustainable and safe disposal of the material. There have been several attempts to try to find safe and environmentally friendly alternative materials to replace plastic mulches. The use of biodegradable films is increasing because they can be left safely in the field after harvesting, but they are not very durable and are much more expensive than plastics. Another alternative is paper. This article reviews the published research on paper mulches and discusses the opportunity that they offer for solving the problems of the immense use of plastics in agriculture and the associated environmental threat. Different mulching materials have been used for different agricultural and horticultural species in different climatic environments, and results vary according to the chosen approach, growing practices, conditions and species, so generalizations are hard to make. One advantage of paper mulches is that they do not create the disposal problems that plastic films always and partially degradable bio-films often do in long-term use. Paper mulches break down naturally after usage and incorporate into the soil. Laying paper mulches in large scale farming is a problem to be solved. The quality of the paper needs to be adapted or improved for mulching purposes, and its price needs to be more competitive with that of plastic mulches. The review shows that there is considerable potential for using paper mulches in agriculture and horticulture. [Tapani Haapala, Pauliina Palonen, Antti Korpela & Jukka Ahokas (2014). Feasibility of paper mulches in crop production —a review. Agricultural and Food Science, 23(1)] Comment

Potential for biological control of the weed Angled Onion (Allium triquetrum) by the fungus Stromatinia cepivora in Australia

Zheljana Peric / WeedsNews4802 / March 13, 2014 / 10:02:16 PM EST / 0 Comments
Abstract: The fungus Stromatinia cepivora (Berk.) Whetzel, which causes white rot of cultivated Allium species, was assessed as a biological control agent for Angled Onion (Allium triquetrum L.), a widespread noxious invasive environmental weed in southern Australia. A. triquetrum showed relatively little genetic diversity, suggesting it was a suitable target for biological control. Genetic analysis of plants from 23 sites in the three main infested Australian states by internal transcribed spacer (ITS) and randomly amplified polymorphic DNA (RAPD) analysis suggested biotypes of A. triquetrum in Australia grouped by state, except for samples from Westernport Bay and Ararat (Victoria). Pathogenicity and virulence of two S. cepivora isolates were assessed on up to 13 A. triquetrum provenances, 6 cultivated Allium species and 9 Australian endemic monocotyledons in test-tube and pot trials. In test-tubes, sclerotia killed plants from all provenances. In pot trials with sclerotia and mycelium, the more pathogenic isolate killed plants from all but one provenance. No A. triquetrum provenance was resistant to S. cepivora, nor were common cultivated Allium species, but common Australian endemic monocotyledons from habitats infested with A. triquetrum showed no disease symptoms 90 days post-inoculation. S. cepivora thus has potential as a biological control agent for A. triquetrum in native bushland in Australia where the risk of it spreading to horticulturally important Alliumspecies is low and can be controlled.[P. Tehranchian, R. J. Adair &A. C. Lawrie (2014). Potential for biological control of the weed Angled Onion (Allium triquetrum) by the fungus Stromatinia cepivora in Australia. Australian Plant Pathology, online March.] Comment

Towards managing weeds in rights-of-way non-chemically: A USA perspective

Zheljana Peric / WeedsNews4795 / February 24, 2014 / 5:48:32 PM EST / 0 Comments
[Beyond Pesticides Fall 2013] — Every year, millions of miles of roads, utility lines, railroad corridors and other types of rights-of-way (ROWs) are polluted with herbicides to control the growth of unwanted plants. However, public concern over the use of dangerous and inadequately tested pesticides has resulted in an increasing effort over the last decade to pass state laws and local policies requiring notification of pesticide use, restrictions on application types and implementation of least-toxic and organic approaches to vegetation management. This report highlights vegetation management on ROWs in select states, and is an update of the original version published 1999 in Pesticides and You. Planting native vegetation, using mechanical, biological and nontoxic vegetation control methods are effective nontoxic solutions. Creating and encouraging stable, low-maintenance vegetation is a more permanent vegetation management strategy. The establishment of desirable plant species that can out-compete undesirable species requires little maintenance and meets the requirements for ROW management. Read the full report …

Glyphosate use linked to gluten intolerance

Zheljana Peric / WeedsNews4793 / February 23, 2014 / 12:19:51 AM EST / 0 Comments
Abstract: Celiac disease, and, more generally, gluten intolerance, is a growing problem worldwide, but especially in North America and Europe, where an estimated 5% of the population now suffers from it. Symptoms include nausea, diarrhea, skin rashes, macrocytic anemia and depression. It is a multifactorial disease associated with numerous nutritional deficiencies as well as reproductive issues and increased risk to thyroid disease, kidney failure and cancer. Here, we propose that glyphosate, the active ingredient in the herbicide, Roundup®, is the most important causal factor in this epidemic. Fish exposed to glyphosate develop digestive problems that are reminiscent of celiac disease. Celiac disease is associated with imbalances in gut bacteria that can be fully explained by the known effects of glyphosate on gut bacteria. Characteristics of celiac disease point to impairment in many cytochrome P450 enzymes, which are involved with detoxifying environmental toxins, activating vitamin D3, catabolizing vitamin A, and maintaining bile acid production and sulfate supplies to the gut. Glyphosate is known to inhibit cytochrome P450 enzymes. Deficiencies in iron, cobalt, molybdenum, copper and other rare metals associated with celiac disease can be attributed to glyphosate’s strong ability to chelate these elements. Deficiencies in tryptophan, tyrosine, methionine and selenomethionine associated with celiac disease match glyphosate’s known depletion of these amino acids. Celiac disease patients have an increased risk to non-Hodgkin’s lymphoma, which has also been implicated in glyphosate exposure. Reproductive issues associated with celiac disease, such as infertility, miscarriages, and birth defects, can also be explained by glyphosate. Glyphosate residues in wheat and other crops are likely increasing recently due to the growing practice of crop desiccation just prior to the harvest. We argue that the practice of “ripening” sugar cane with glyphosate may explain the recent surge in kidney failure among agricultural workers in Central America. We conclude with a plea to governments to reconsider policies regarding the safety of glyphosate residues in foods. [Anthony Samsel & Stephanie Seneff (2013). Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdisciplinary Toxicology, 6(4), 159–184.] Comment

Degradation of potentially biodegradable plastic mulch films at three diverse U.S. locations

Zheljana Peric / WeedsNews4791 / February 22, 2014 / 11:30:07 PM EST / 0 Comments
Abstract: For widespread adoption of biodegradable plastics as agricultural mulches, dependable biodegradation across contrasting conditions is necessary. The in situ degradation of four potentially biodegradable mulches (two commercially available starch-based films, one commercially available cellulose paper mulch, and one experimental spunbond polylactic acid mulch) were evaluated by measuring percent area remaining (PMAR) after burial for 6, 12, 18 and 24 months in high tunnel and open field tomato production systems at three geographically distinct U.S. locations (Knoxville, TN; Lubbock, TX; Mount Vernon, WA). The PMAR of the mulches did not differ between high tunnel and open field systems at any location, and PMAR of cellulose mulch was 0% within 12 months but >90% for experimental spunbond at 24 months. The PMAR of the two starch-based products did vary by location, and was lowest at Lubbock (˜2%) compared to Knoxville (49%) or Mount Vernon (89%). Relative to the other two locations, Lubbock had the greatest soil diurnal temperature range, maximum daily soil temperature, an alkaline soil pH and a microbial community structure characterized by a relatively high abundance of fungi. Mulch type and geographic location exerted a greater influence on PMAR than did production system, and abiotic and biotic variables influenced degradation. [Chenhui Li, Jennifer Moore-Kucera, Carol Miles, Karen Leonas, Jaehoon Lee, Andrew Corbin & Debra Inglis (2014). Degradation of potentially biodegradable plastic mulch films at three diverse U.S. locations. Agroecology and Sustainable Food Systems, online 20 Feb] Comment

Diuron found to induce bladder cancers

Zheljana Peric / WeedsNews4789 / February 21, 2014 / 7:58:46 AM EST / 0 Comments
Abstract: Diuron, a high volume substituted urea herbicide, induced high incidences of urinary bladder carcinomas and low incidences of kidney pelvis papillomas and carcinomas in rats exposed to high doses (2500 ppm) in a 2-year bioassay. Diuron is registered for both occupational and residential uses and is used worldwide for more than 30 different crops. The proposed rat urothelial mode of action (MOA) for this herbicide consists of metabolic activation to metabolites that are excreted and concentrated in the urine, leading to cytotoxicity, urothelial cell necrosis and exfoliation, regenerative hyperplasia, and eventually tumors. We show evidence for this MOA for diuron using the International Programme on Chemical Safety (IPCS) conceptual framework for evaluating an MOA for chemical carcinogens, and the United States Environmental Protection Agency (USEPA) and IPCS framework for assessing human relevance. [Mitscheli Sanches Da Rocha et al. (2014). Diuron-induced rat urinary bladder carcinogenesis: Mode of action and human relevance evaluations using the International Programme on Chemical Safety framework. Critical Reviews in Toxicology , on-line February 11] Comment

Use of the silverleaf fungus Chondrostereum purpureum for biological control of stump-sprouting, riparian weedy tree species in New Zealand

Zheljana Peric / WeedsNews4787 / February 18, 2014 / 10:19:06 PM EST / 0 Comments
Abstract: Conventional willow control in wetland and riparian areas of New Zealand is undertaken using cut-stump and/or drill and injection application of glyphosate. The presence of herbicide residues in catchment water supplies has seen the investigation of non-chemical alternatives to poplar and willow control in Auckland water catchment areas. We have demonstrated, in glasshouse trials, the efficacy of an aqueous, gel-based formulation of Chondrostereum purpureum to control the regrowth of crack and grey willow (Salix fragilis and S. cinerea). Chondrostereum purpureum isolate ICMP 16392 (isolated from a Prunus sp.) produced the fastest biomass accumulation in liquid culture. Crack willow was significantly more susceptible to cut-stump infection by C. purpureum than grey willow in the glasshouse trial at the end of the 23-week period. Two different formulations were tested; at the end of the trial, there was no significant difference between them with respect to monthly biomass accumulation. Successful field applications of C. purpureum through cut and paste and drill and injection were confirmed by the presence of fruiting bodies on both treated species. Resprouting ability as measured by shoot number was significantly lower on C. purpureum inoculated stumps.[S. E. Bellgard, V. W. Johnson, D. J. Than, N. Anand, C. J. Winks, G. Ezeta & S. L. Dodd (2014). Use of the silverleaf fungus Chondrostereum purpureum for biological control of stump-sprouting, riparian weedy tree species in New Zealand. Australasian Plant Pathology, February] Comment

USA's EPA awards more than $US 3 million to researchers studying how chemical exposures impact brain development

Zheljana Peric / WeedsNews4785 / February 17, 2014 / 10:19:19 PM EST / 0 Comments
[EPA 12/02/14] — The U.S. Environmental Protection Agency (EPA) has announced over $3 million in grants to research institutions to better understand how chemicals interact with biological processes and how these interactions may lead to altered brain development. The studies are focused on improving EPA’s ability to predict the potential health effects of chemical exposures. “This research will transform our understanding of how exposure to chemicals during sensitive lifestages affects the development of the brain,” said Lek Kadeli, acting assistant administrator for EPA’s Office of Research and Development. “By better predicting whether chemicals have the potential to impact health and human development, these grants will not only advance the science necessary to improve chemical safety but protect the well being and futures of children in this nation.These grants focus on developing better adverse outcome pathways (AOPs), which are models that predict the connection between exposures and the chain of events that lead to an unwanted health effect. AOPs combine vast amounts of data from different sources to depict the complex interactions of chemicals with biological processes, and then extend this information to explain an adverse health effect. EPA expects to use the knowledge gained from this research to develop efficient and cost-effective models to better predict if and how exposure to environmental chemicals may lead to developmental neurotoxicity. Comment

Glyphosate carryover in seed potato: Effects on mother crop and daughter tubers

Zheljana Peric / WeedsNews4781 / February 9, 2014 / 12:09:50 AM EST / 0 Comments
Abstract: Field studies were conducted in 2008 and 2009 in Aberdeen, ID, Ontario, OR, and Paterson, WA to determine the effect of simulated glyphosate drift on ‘Ranger Russet’ potato during the application year and the crop growing the next year from the daughter tubers. Glyphosate was applied at 8.5, 54, 107, 215, and 423 g ae ha−1 which corresponds to 1/00, 1/16, 1/8, ¼, and 1/2 of the lowest recommended single-application rate for glyphosate-resistant corn and sugar beet of 846 g ha–1. Glyphosate was applied when potato plants were at 10 to 15 cm tall (Early), or at stolon hooking (H), tuber initiation (TI), or during mid-bulking (MB). In general, the MB applications caused less visual foliar injury to the mother crop than earlier applications at ID or OR, and H applications at WA. Mother crop injury increased as glyphosate rate increased regardless of location, application timing, and rating date. U.S. No.1 and total tuber yields were usually related to the injury level resulting from glyphosate application timings and rates. Although injury to the mother crop from glyphosate applied at MB usually was the lowest compared to injury from other application timings, when daughter tubers from that timing were planted the following year, emergence, plant vigor, and yield was most detrimentally impacted compared with that of daughter tubers from other timing treatments. MB daughter tuber emergence was less than 30 % of the nontreated control tuber emergence while emergence of daughter tubers from the other treatments was 60 to 95 %. As rate of glyphosate applied to the mother crop increased, daughter tuber emergence decreased. When MB daughter tubers did emerge, plants were chlorotic and stunted as if the plants had been directly sprayed with glyphosate. Regardless of whether the daughter tubers had defects or not, results the following year were the same. Implications are that if a mother seed crop encounters glyphosate during bulking, injury may not even be noticeable on the foliage or the tubers, however, emergence, vigor, and yield of the crop growing the following year from the daughter tubers could be greatly impacted. [Pamela J. S. Hutchinson, Joel Felix & Rick Boydston (2014). Glyphosate carryover in seed potato: Effects on mother crop and daughter tubers. Potato Research: January] Comment

Glyphosate persistence in seawater

Zheljana Peric / WeedsNews4779 / February 8, 2014 / 11:42:10 PM EST / 0 Comments
Abstract: Glyphosate is one of the most widely applied herbicides globally but its persistence in seawater has not been reported. Here we quantify the biodegradation of glyphosate using standard “simulation” flask tests with native bacterial populations and coastal seawater from the Great Barrier Reef. The half-life for glyphosate at 25 °C in low-light was 47 days, extending to 267 days in the dark at 25 °C and 315 days in the dark at 31 °C, which is the longest persistence reported for this herbicide. AMPA, the microbial transformation product of glyphosate, was detected under all conditions, confirming that degradation was mediated by the native microbial community. This study demonstrates glyphosate is moderately persistent in the marine water under low light conditions and is highly persistent in the dark. Little degradation would be expected during flood plumes in the tropics, which could potentially deliver dissolved and sediment-bound glyphosate far from shore. [Philip Mercurio,Florita Flores, Jochen F. Mueller, Steve Carter & Andrew P. Negri (2014). Glyphosate persistence in seawater. Marine Pollution Bulletin, online Jan 24] Comment

Superweeds: How biotech crops bolster the pesticide industry

Zheljana Peric / WeedsNews4775 / February 8, 2014 / 11:22:22 PM EST / 0 Comments
[food&waterwatch 1 July 2013] — Genetically engineered (GE) crops were first approved in the United States in the 1990s, and since then the United States has been the biggest global adopter of this technology. GE crops were supposed to improve yields, lower costs for farmers and reduce agriculture’s environmental impact. Yet nearly 20 years after their introduction, genetically engineered crops have not provided the benefits promised by the companies that patented them. Food & Water Watch examined U.S. Department of Agriculture (USDA) and U.S. Environmental Protection Agency (EPA) data to document the increased use of herbicides that has accompanied the adoption of herbicide-tolerant GE crops. Our analysis looks at the rapid proliferation of GE crops and affiliated pesticides in the United States and points out the interdependent relationship between these two industries that also fuels the crisis of weed resistance. Food & Water Watch evaluated data from the International Survey of Herbicide Resistant Weeds that reveal burgeoning herbicide-resistant weeds caused by the over-reliance on glyphosate for broad control of weeds. These data make it clear that the problem of herbicide-resistant weeds will not be solved with the intensified use of older, more toxic herbicides like 2,4-D and dicamba. Continue reading to download report and view video …

Organic farmer knowledge and perceptions are associated with on-farm weed seedbank densities in Northern New England

Zheljana Peric / WeedsNews4774 / February 8, 2014 / 11:15:56 PM EST / 0 Comments
Abstract: Weed management remains a high priority for organic farmers, whose fields generally have higher weed density and species diversity than those of their conventional counterparts. We explored whether variability in farmer knowledge and perceptions of weeds and weed management practices were predictive of variability in on-farm weed seedbanks on 23 organic farms in northern New England. We interviewed farmers and transcribed and coded interviews to quantify their emphasis on concepts regarding knowledge of ecological weed management, the perceived risks and benefits of weeds, and the perceived risks and benefits of weed management practices. To characterize on-farm weed seedbanks, we collected soil samples from five fields at each farm (115 fields total) and measured germinable weed seed density. Mean weed seed density per farm ranged from 2,775 seeds m−2 to 24,678 seeds m−2 to a soil depth of 10 cm. Farmers most often reported hairy galinsoga and crabgrass species (Digitaria spp.) as their most problematic weeds. The proportion of the sum of these two most problematic weeds in each farm's seedbank ranged from 1 to 73% of total weed seed density. Farmer knowledge and perceptions were predictive of total seed density, species richness, and proportion of hairy galinsoga and crabgrass species. Low seed densities were associated with farmers who most often discussed risks of weeds, benefits of critical weed-free management practices, and learning from their own experience. These farmers also exhibited greater knowledge of managing the weed seedbank and greater understanding of the importance of a long-term strategy. Targeted education focusing on this set of knowledge and beliefs could potentially lead to improved application and success of ecological weed management in the future, thus decreasing labor costs and time necessary for farmers to manage weeds. [Randa Jabbour , Eric R. Gallandt , Sarah Zwickle , Robyn S. Wilson & Doug Doohan (2014). Organic farmer knowledge and perceptions are associated with on-farm weed seedbank densities in Northern New England. on-line 28 Jan]

Major pesticides are more toxic to human cells than their declared active principles

Zheljana Peric / WeedsNews4771 / February 7, 2014 / 11:15:19 PM EST / 0 Comments
Abstract: Pesticides are used throughout the world as mixtures called formulations. They contain adjuvants, which are often kept confidential and are called inerts by the manufacturing companies, plus a declared active principle (AP), which is usually tested alone. This is true even in the longest toxicological regulatory tests performed on mammals. We tested the toxicity of 9 pesticides, comparing active principles and their formulations, on three human cell lines (HepG2, HEK293 and JEG3). We measured mitochondrial activities, membrane degradations, and caspases 3/7 activities. Glyphosate, isoproturon, fluroxypyr, pirimicarb, imidacloprid, acetamiprid, tebuconazole, epoxiconazole and prochloraz constitute respectively the active principles of 3 major herbicides, 3 insecticides and 3 fungicides. Fungicides were the most toxic from concentrations 300-600 times lower than agricultural dilutions, followed by herbicides, and then insecticides, with very similar profiles in all cell types. The human placental JEG3 cells appeared to be the most sensitive. Despite its relatively benign reputation, Roundup was by far the most toxic among the herbicides and insecticides tested. Most importantly, 8 formulations out of 9 were several hundred times more toxic than their active principle. Our results challenge the relevance of the Acceptable Daily Intake for pesticides because this norm is calculated from the toxicity of the active principle alone. The study of combinatorial effects of several APs together may be of only secondary importance if the toxicity of the combinations of each AP with its adjuvants is neglected or unknown. Chronic tests on pesticides may not reflect relevant environmental exposures if only one ingredient of these mixtures is tested alone. [Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini G.E. (2014). Major pesticides are more toxic to human cells than their declared active principles. BioMed Research Interntional, on-line 07/02/24] Comment

Understanding misunderstandings in invasion science: why experts don’t agree on common concepts and risk assessments

Zheljana Peric / WeedsNews4769 / February 7, 2014 / 10:40:08 PM EST / 0 Comments
Abstract: Understanding the diverging opinions of academic experts, stakeholders and the public is important for effective conservation management. This is especially so when a consensus is needed for action to minimize future risks but the knowledge upon which to base this action is uncertain or missing. How to manage non-native, invasive species (NIS) is an interesting case in point: the issue has long been controversial among stakeholders, but publicly visible, major disagreement among experts is recent. To characterize the multitude of experts’ understanding and valuation of non-native, NIS we performed structured qualitative interviews with 26 academic experts, 13 of whom were invasion biologists and 13 landscape experts. Within both groups, thinking varied widely, not only about basic concepts (e.g., non-native, invasive) but also about their valuation of effects of NIS. The divergent opinions among experts, regarding both the overall severity of the problem in Europe and its importance for ecosystem services, contrasted strongly with the apparent consensus that emerges from scientific synthesis articles and policy documents. We postulate that the observed heterogeneity of expert judgments is related to three major factors: (1) diverging conceptual understandings, (2) lack of empirical information and high scientific uncertainties due to complexities and contingencies of invasion processes, and (3) missing deliberation of values. Based on theory from science studies, we interpret the notion of an NIS as a boundary object, i.e., concepts that have a similar but not identical meaning to different groups of experts and stakeholders. This interpretative flexibility of a concept can facilitate interaction across diverse groups but bears the risk of introducing misunderstandings. An alternative to seeking consensus on exact definitions and risk assessments would be for invasive species experts to acknowledge uncertainties and engage transparently with stakeholders and the public in deliberations about conflicting opinions, taking the role of honest brokers of policy alternatives rather than of issue advocates. [Franziska Humair, Peter J. Edwards, Michael Siegrist & Christoph Kueffer (2014).
Understanding misunderstandings in invasion science: why experts don’t agree on common concepts and risk assessments. NeoBiota 20, 1-30] Comment

Avoiding atrazine would result in an economic benefit to farmers

Zheljana Peric / WeedsNews4766 / January 31, 2014 / 7:54:55 AM EST / 0 Comments
[Beyond Pesticides, January 17, 2014] — A new economic study, Would banning atrazine benefit farmers?, published in the International Journal of Occupational and Environmental Health demonstrates that eliminating the herbicide atrazine, widely used on U.S. corn crops, will economically benefit corn growers. The study examines the research produced by the Atrazine Benefits Team (ABT), a group assembled by atrazine manufacturer Syngenta, revealing that the industry-funded studies significantly overestimate the benefits of atrazine without considering the value of nonchemical weed management techniques. Research, led by Frank Ackerman, PhD., professor at Tufts University in the Global Development and Environment Institute, questions the economic viability of atrazine in Syngenta’s study. Researchers critically review five papers released by ABT in 2011, which claim that the withdrawal of atrazine would diminish corn yields by 4.4%, increasing corn prices by 8%. Using these assumptions, Dr. Ackerman and his team calculated that corn growers’ revenue would actually increase by 3.2%, providing a total of $1.7 billion to farmers and the U.S. economy with minimal price changes for consumers. In short, because of price elasticity, eliminating atrazine would improve farmer revenues. Continue reading …

Predictive modelling of weed seed movement in response to superficial tillage tools

Zheljana Peric / WeedsNews4764 / January 18, 2014 / 9:55:31 PM EST / 0 Comments
Abstract: Weed seed burial and excavation by tillage determines seed depth, seed survival, germination and pre-emergent seedling mortality. However, quantitative estimates of seed burial are available for only a few tools and often without reference to soil structure, moisture or tillage depth. This study proposes a conceptual model for predicting weed seed movements during superficial tillage in response to the type of tool, tillage depth and soil structure. The proposed model was calibrated with field data collected using coloured plastic beads as weed seed proxies. Beads were placed at different vertical and horizontal positions before tillage, using augers to preserve soil structure and collected after tillage by opening trenches and counting beads found at different depths. Approximately 33% of the beads were retrieved and used to establish bead distributions from which model parameters were estimated. Cross-validation showed that prediction quality was satisfactorily (modelling efficiency = 0.85, minimum rMSEP = 0.11) with most of the error associated with using a harrow in compacted soil. Subsequently, the new model was integrated into the existing weed dynamics model FlorSys, and simulations were run to predict weed emergence and dynamics for different tillage practices. With a surface seed bank, total emergence was highest for shallow operations (harrow, discs) and lowest for deep operations (chisel, mouldboard plough). Emergence was also lower in compacted soils. Differences among tillage tools persisted when weed dynamics were simulated over several years, with mouldboard ploughing generally having the lowest density even though this tool was only used every three years. Superficial tillage which left seeds closest to the soil surface resulted in the highest weed density. Also, for species with heavy seeds densities generally increased with ploughing. These simulations confirm the utility of the new model, but additional studies are needed to examine other tillage, management practices and weed species combinations.[Nathalie Colbach, Hugues Busset, Jean Roger-Estrade & Jacques Caneill (2013). Predictive modelling of weed seed movement in response to superficial tillage tools. Soil and Tillage Research, 138, 1–8] [Photo: Mouldboard plough being tested for weed control in Western Australia] Comment

Assessment of sustainable vermiconversion of water hyacinth by Eudrilus eugeniae and Eisenia fetida

Zheljana Peric / WeedsNews4762 / January 16, 2014 / 8:05:21 AM EST / 0 Comments
Abstract: The present work has assessed sustainable vermiconversion of aquatic weed water hyacinth (Eichornia crassipes). The garden soil, water hyacinth and cow dung were taken in the following the combinations of 1: 2 : 1, 2: 1: 1 and 1 : 1: 2. Two species of earthworms Eudrilus eugeniae and Eisenia fetida were used for the experiment. The total nitrogen (0.18% in control and 1.68% in earthworm treated) and phosphate (0.63 % in control and 1.64 % in earthworm treated) levels were increased and toxic heavy metals zinc (7.66 ppm in control and 2.58 ppm in earthworm treated) and copper (6.68 ppm in control and 1.15 ppm in earthworm treated) were significantly decreased. The earthworm enriches the compost with various nutrients for plant and microbial growth. Plant growth studies were conducted in all the combination of water hyacinth, maximum growth of root length (8.9cm and 7.2 in control) and shoot length (21.6cm and 16.2 in control) observed compare to control. Gut microbial analysis revealed that Bacillus cereus, Micrococcus luteus were predominantly present in the earthworm. The study recommended that the aquatic weed compost was suitable of agricultural usage. [N. Kannadasan, Nirmala Natarajan, N. Anbusaravanan, P. Sekar & R. Krishnamoorthy (2013). Assessment of sustainable vermiconversion of water hyacinth by Eudrilus eugeniae and Eisenia fetida. Journal of Applied and Natural Science, 5(2): 451-454] [Photo: A similar idea being used in South Africa]

Impact of EU pesticide reduction strategy and implications for crop protection in the UK and the rest of Europe

Zheljana Peric / WeedsNews4757 / January 13, 2014 / 7:56:31 AM EST / 0 Comments
Abstract: Around 75% of active ingredients (a.i.) used as plant protection products in Europe before 1993 have been withdrawn from the market since the introduction of Directive 91/414/EEC, concerning the placing on the market of plant protection products. Although a large number of pesticides have been lost, some were replaced by 'better', 'less toxic' or less persistent molecules, because industry did not want to continue to support outdated molecules and spend money on all the extra tests required. However, in reducing the number there should have been a careful assessment of whether any should be retained to allow better resistance management strategies to be maintained. The approval process for agricultural pesticides that can be used in agriculture is a continuous one and we can expect additional important a.i. to be withdrawn, as has been seen with the EC decision in April 2013, to ban three neonicotinoid insecticides (NNIs) for two years. The EU Pesticide Reduction Strategy responds to public concern and medical evidence about the harmful effects of pesticides on human health. While most people would agree that we should try to minimise the use of conventional pesticides in our environment, there is considerable controversy over where the balance should be struck, between risk and benefit. The debate is highly polarised, between those who think the risk of harm from pesticides is already being managed by strict regulation of their use and, those who think that a precautionary approach should be adopted and that potential hazard is a reasonable criterion for removal. The agricultural industry, including most farmers, argue that further pesticide removals will result in significant decreases in European food production and, therefore, higher food prices. Environmental and other campaigning organizations such as Friends of the Earth, the Soil Association and The Pesticide Action Network, believe that the rate of removal of the most 'hazardous' pesticides should be increased and that there should be much less use of 'derogations'. [Hillocks, Rory (2013). Impact of EU pesticide reduction strategy and implications for crop protection in the UK and the rest of Europe. Outlooks on Pest Management, 24(5), 206-209] Comment

Dramatic decline in industrial agriculture could herald 'peak food'

Zheljana Peric / WeedsNews4756 / January 8, 2014 / 7:56:41 AM EST / 0 Comments
[EarthInsight 20 Dec 2013 by Nafeez Ahmed] — Industrial agriculture could be hitting fundamental limits in its capacity to produce sufficient crops to feed an expanding global population according to new research published in Nature Communications.The study by scientists at the University of Nebraska-Lincoln argues that there have been abrupt declines or plateaus in the rate of production of major crops which undermine optimistic projections of constantly increasing crop yields. As much as "31% of total global rice, wheat and maize production" has experienced "yield plateaus or abrupt decreases in yield gain, including rice in eastern Asia and wheat in northwest Europe." The declines and plateaus in production have become prevalent despite increasing investment in agriculture, which could mean that maximum potential yields under the industrial model of agribusiness have already occurred. Crop yields in "major cereal-producing regions have not increased for long periods of time following an earlier period of steady linear increase." Continue reading ....

Economics of organic versus chemical farming for three crops in Andhra Pradesh, India

Zheljana Peric / WeedsNews4755 / January 7, 2014 / 11:03:33 PM EST / 0 Comments
Abstract: To tackle the challenge of food grain production and food security, chemical agriculture advocates call for the continuing or higher use of chemical fertilizers and synthetic pesticides. However, the continuous use and higher reliance on these inputs can lead to a reduction in crop productivity, deterioration in the quality of natural resources and the eco-system. Organic farming offers a solution for sustainable agricultural growth and safeguarding the ecosystem. A conversion from chemical farming to organic farming can be a lengthy process, and during its course the farmer may incur a loss in income. The farmer will switch over only when he is convinced that in the long run, the benefits from organic farming are more than from chemical farming. A study of the economics of organic versus chemical farming may help policy makers to take appropriate measures for the spread of organic farming, which in turn has a bearing on the incomes of farmers, health conditions of the people and the environment. The present study compared the economics of organic farmers (N=350) and chemical farmers (N=200) for three crops, paddy, redgram, and groundnuts, in the state of Andhra Pradesh, a south eastern coastal state of India. It was found that organic farmers are earning a gross income of 5%, 10% and 7% more compared to the chemical farmers of paddy, redgram and groundnut, respectively, and with lower input costs the profits earned by the organic farmers are higher by 37%, 33% and 59% for the selected crops respectively. Organic farming is generally more profitable in terms of financial costs and returns than chemical farming, irrespective of the crop or the size of farm (the exceptions being small redgram farms and large goundnut farms). An analysis of the farmers’ perception of organic farming reveals that electronic media (television) is the prime motivator for farmers to adopt organic practices. Farmers believed that organic farming improves soil fertility and their profits in the long run. [P. Sri Krishna Sudheer (2013). Economics of organic versus chemical farming for three crops in Andhra Pradesh, India. Journal of Organic Systems, 8(2), 36-49]

Denmark: Load index now guides pesticide tax

Zheljana Peric / WeedsNews4742 / December 16, 2013 / 10:15:09 PM EST / 0 Comments
[endure 01 August 2013 by Janne Hansen] — With effect from 1 July 2013 a new pesticide strategy has been implemented in Denmark, writes Janne Hansen. The aim is to reduce the use of pesticides, particularly those that have a high impact on the environment and human health. The most important change is the amended tax on pesticides. The tax will increase the cost of pesticides having a high potential impact on health and the environment. The intention is to motivate farmers and other pesticide users to reduce their use and the load of potentially harmful pesticides. The pesticide strategy will continue where Denmark’s Green Growth programme left off (read about the Green Growth programme in our original Denmark Country Profile) and many of the activities that were originally planned as part of Green Growth continue. The most important change ensuing from the new pesticide strategy is that the Treatment Frequency Index will be replaced by a Pesticide Load Indicator. This means that pesticides will be taxed according to their load indicator instead of a value added tax regardless of load. Continue reading …

Suppressive fodder plants as part of an integrated management program for Parthenium hysterophorus L.

Zheljana Peric / WeedsNews4739 / December 16, 2013 / 9:53:06 PM EST / 0 Comments
Abstract: Parthenium hysterophorus L. is an alien invasive weed in both Australia and Pakistan infesting rangelands, reducing fodder biomass and causing significant livestock production losses. Previous studies have identified a number of introduced and native fodder species that can suppress the growth of P. hysterophorus in glasshouse trials. These species can also provide an adequate fodder biomass for livestock production. In this study 11 of these fodder species were sown at the recommended rates into P. hysterophorus infested field sites at Injune and Monto, Australia while an additional five species were sown into similar infested field sites at Islamabad and Mardan, in northern Pakistan. Measurements taken on dry shoot biomass production of the fodder species were used to determine their P. hysterophorus growth suppressing ability and fodder biomass production. In Australia, all of the fodder species suppressed the growth of P. hysterophorus, with Setaria incrassata, Cenchrus ciliaris, Clitoria ternatea, Themeda triandra and Astrebla squarrosa (Injune field site), and Chloris gayana, C. ciliaris, Dichanthium sericeum, Clitoria ternatea and Bothriochloa insculpta (Monto field site) all suppressing growth by >62% and producing at least 329 g m−2 of dry fodder biomass. In Pakistan, all of the fodder species suppressed the growth of P. hysterophorus, with Sorghum almum, C. ciliaris and C. gayana suppressing growth by >73% and producing at least 622 g m−2 of dry fodder biomass. Some species such as S. incrassata performed well at just one field site, while others (C. ciliaris and C. gayana) performed well at all the four field sites, indicating that such plants could be considered as part of a new integrated weed management system for P. hysterophorus in both Australia and Pakistan. [Naeem Khana, Asad Shabbira, Doug Georgea, Gul Hassanb & Steve W. Adkins (2014). Suppressive fodder plants as part of an integrated management program for Parthenium hysterophorus L. Field Crops Research, 156, 172–179] [Photo: Setaria incrassata] Comment

Exploring integrated crop–livestock systems in different ecoregions of the United States

Zheljana Peric / WeedsNews4737 / December 16, 2013 / 9:06:30 PM EST / 0 Comments
Abstract: Large-scale, energy-intensive, specialized production systems have dominated agricultural production in the United States for the past half-century. Although highly productive and economically successful, there is increasing concern with unintended negative environmental impacts of current agricultural systems. Production systems integrating crops and livestock have potential for providing additional ecosystem services from agriculture by capturing positive ecological interactions and avoiding negative environmental outcomes, while sustaining profitability. A diversity of ecologically sound integrated crop-livestock systems have been and can be employed in different ecoregions: sod-based crop rotations, grazing cover crops in cash-crop rotations, crop residue grazing, sod intercropping, dual-purpose cereal crops, and agroforestry/silvopasture. Improved technologies in conservation tillage, weed control, fertilization, fencing, and planting, as well as improved plant genetics offer opportunities to facilitate successful adoption of integrated systems. This paper explores the use and potential of integrated crop-livestock systems in achieving environmental stewardship and maintaining profitability under a diversity of ecological conditions in the United States. [R. Mark Sulca, Alan J. Franzluebbers (2013). Exploring integrated crop–livestock systems in different ecoregions of the United States. European Journal of Agronomy, online 14 November. ] Comment

Herbicide impact on non-target plant reproduction: What are the toxicological and ecological implications?

Zheljana Peric / WeedsNews4735 / December 15, 2013 / 11:13:07 PM EST / 0 Comments
Abstract: Declining plant diversity and abundance have been widely reported in agro-ecosystems of North America and Europe. Intensive use of herbicides within cropfields and the associated drift in adjacent habitats are partly responsible for this change. The objectives of this work were to quantify the phenological stages of non-target plants in in-situ field situations during herbicide spray and to compare plant susceptibility at different phenological stages. Results demonstrated that a large number of non-target plants had reached reproductive stages during herbicide spray events in woodlots and hedgerows, both in Canada and Denmark where vegetation varies considerably. In addition, delays in flowering and reduced seed production occurred widely on plants sprayed at the seedling stage or at later reproductive periods, with plants sprayed at reproductive stages often exhibiting more sensitivity than those sprayed as seedlings. Ecological risk assessments need to include reproductive endpoints. [C. Boutina, B. Strandbergb, D. Carpentera, S.K. Mathiassenc & P.J. Thomasa (2013). Herbicide impact on non-target plant reproduction: What are the toxicological and ecological implications? Environmental Pollution, 185, 295–306] Comment

Shoppers willing to pay for products with “free of” claims on label, study

Zheljana Peric / WeedsNews4733 / December 15, 2013 / 10:24:02 PM EST / 0 Comments
[AFN 04 Dec 2013 by Sophie Langley] — Consumers crave more information about how their food is produced, and especially about the potentially harmful ingredients that are not included in the product, according to new research from Cornell University. The laboratory study of 351 shoppers found that consumers were willing to pay a premium when a product label claimed a product was “free of” something, but only if the package included “negative” information on whatever the product was “free of”. For example, a food labelled “free” of a food dye will compel some consumers to buy that product. But even more people would buy the product if that same label also included information about the risks associated with ingesting such dyes. “What did surprise us was the effect of supplementary information,” said Harry M Kaiser, a Cornell Professor whose field of study includes product labelling. “Even seemingly negative information was valued over just the label itself,” he said. When provided more information about ingredients, consumers were more confident about their decisions and valued the product more, according to the researchers. Published in November 2013 in the journal Applied Economic Perspectives and Policy, the researchers said their study might interest food manufacturing companies, government policy makers and consumers alike. Other authors of the journal article were Jura Liaukonyte, Nadia A. Streletskaya and Bradley J. Rickard, all of the Dyson School. The study was supported by internal funds from Cornell’s College of Agriculture and Life Sciences. Comment

Study finds herbicide and other contaminants are not removed from sewage

Zheljana Peric / WeedsNews4732 / December 15, 2013 / 10:15:20 PM EST / 0 Comments
[Environmental Health News 22 Nov 2013 by Brian Blenkowski] — Wastewater treatment plants discharge 4.8 billion gallons of treated effluent into the Great Lakes basin every day. Only about half of the prescription drugs and other newly emerging contaminants in sewage are removed by treatment plants. That’s the finding of a new report by the International Joint Commission, a consortium of officials from the United States and Canada who study the Great Lakes. The impact of most of these “chemicals of emerging concern” on the health of people and aquatic life remains unclear. “The compounds show up in low levels – parts per billion or parts per trillion – but aquatic life and humans aren’t exposed to just one at a time, but a whole mix,” said Antonette Arvai, physical scientist at the International Joint Commission and the lead author of the study. “We need to find which of these chemicals might hurt us.” The scientists reviewed 10 years of data from wastewater treatment plants worldwide to see how well they removed 42 compounds that are increasingly showing up in the Great Lakes. Six chemicals, including a herbicide, were detected frequently and had a low rate of removal in treated effluent. Comment

Impacts of plant invasions become less robust over time: Invasive plants are more likely to be replaced by other 'invasives'

Zheljana Peric / WeedsNews4730 / December 8, 2013 / 9:58:26 PM EST / 0 Comments
[Science Daily 20 Nov 2013] — Among the most impressive ecological findings of the past 25 years is the ability of invasive plants to radically change ecosystem function. Yet few if any studies have examined whether ecosystem impacts of invasions persist over time, and what that means for plant communities and ecosystem restoration. UC Santa Barbara's Carla D'Antonio, Schuyler Professor of Environmental Studies, has conducted one of the only long-term studies of plant invader impacts that spans two decades. Returning to the same grass-invaded field sites in Hawaii Volcanoes National Park that she used in her 1990-1995 studies, D'Antonio, along with postdoctoral scholar Stephanie Yelenik, gathered new data that shed light on mechanisms regulating exotic plant dominance and community change through invasion. The findings are published online in Nature. "We were able to take advantage of detailed studies I and others had conducted in the 1990s. We permanently marked sites we had set up and were able to go back and gain insight into how plant invasions changed over time without management," said D'Antonio, who also is a professor in the Department of Ecology, Evolution and Marine Biology. "Such studies are important because managers have little money to control invasive species or to study how impacts might change without management." Continue reading …

Rare weeds under threat in Britain

Zheljana Peric / WeedsNews4726 / December 8, 2013 / 9:03:58 PM EST / 0 Comments
[Plantlife 29 Nov 2013]England’s farmland is rapidly becoming the domain of a few species where once there was abundant diversity, with increased intensification resulting in wild flowers such as poppy being squeezed out of the landscape. Of the 1,556 flowers in the British flora, 580 are considered threatened or rare in England; the majority (97%) are found on farmland. As they disappear, so the colour is wiped from our countryside. Once so abundant they were the scourge of farmers, now some farmland flowers are on the verge of extinction. Agri-environment is vital for helping to support our threatened flora yet, in its current state, is badly flawed in its results for wild plants. Negotiations within the EU have reached a tipping point and the next Common Agricultural Policy is being settled over the forthcoming months. It is imperative that environment measures within the Rural Development Programme for England protect this unrivalled natural and cultural heritage. Continue reading …

Practices to encourage loss of weed seedbanks are key to weed management

Zheljana Peric / WeedsNews4720 / December 6, 2013 / 9:53:05 PM EST / 0 Comments
[PRWeb 06 Dec 2013] — A study featured in Weed Science presents results of field experiments looking at post-dispersal seed loss of five of the most problematic weeds. The authors saw a natural reduction in the percentage of active seedbank, and suggest that practicing certain techniques could provide sustainable weed management. Nature assists in the loss of weed seed through predation, decay, and loss of viability. Integrated weed management strategies that facilitate these processes can lead to high levels of weed seed loss.
The journal article presents results of field experiments conducted at two locations in Arkansas between November 2010 and October 2011. Researchers studied post-dispersal seed loss of five of the most problematic weeds in the midsouthern United States—barnyardgrass, johnsongrass, pitted morningglory, Palmer amaranth, and red rice. After harvest, weeds seeds left on the ground are vulnerable, and biological interventions can keep them from becoming seedlings and the next season’s weeds. The seeds provide food sources for ants, rodents, and birds. Pathogenic microorganisms can attack seeds, causing decay. In addition, physiological aging can affect the longevity and viability of seeds. Continue reading …

Canadian citizen group seeks cosmetic pesticide ban in Stratford

Zheljana Peric / WeedsNews4719 / December 6, 2013 / 9:12:14 PM EST / 0 Comments
[Daily Business Buzz 14 Nov 2013] — A Canadian citizens group landed at Stratford town council meeting Wednesday, asking it to become the first in the Prince Edward Island province to issue a municipal ban on cosmetic pesticides. Maureen Kerr, on behalf of Pesticide Free PEI, read a letter to council from resident Keslie MacEachern. "It baffles my mind that even with so many other provinces in Canada banning cosmetic pesticides and the Canadian and American medical and paediatric societies stating the real risks and dangers of cosmetic pesticides, that nothing has seemed to change," said MacEachern, who says she is a mother of a toddler and another baby on the way. "My wish is that the Town of Stratford will be the first town in Prince Edward Island to stand up and protect the health of its community by banning the residential use of cosmetic pesticides," read Kerr. Already on it, but not possible yet, said Councillor Diane Griffin. She said that the current P.E.I. Municipalities Act gives no opportunity for such a ban, unlike Quebec where the Supreme Court of Canada granted that opportunity to the town of Hudson. Stratford is nevertheless gearing up for public consultation on the issue of cosmetic pesticides. Changes by the province proposed, but yet unseen, to the Municipalities Act may give Stratford the ban opportunity at some later date, said Griffin. She expects a multi-prong strategy of focus groups, emails, surveys and meetings to roll out in the new year, inviting Stratford residents to weigh in on the issue.] Resident Roger Gordon spoke, challenging Stratford to "pick up the ball" that the province dropped in passing the "worst regulations in the country ... Protect the citizens from the spray-wielding intruders who invade our community with their trucks, drums, and heinous spraying equipment," said Gordon. He asked council to prepare for "the expected onslaught in the spring by the purveyors of poisons." There are lawyers willing to help Stratford with that, said Gordon. [Photo: Maureen Kerr and Roger Gordon prepare to make a presentation to the monthly meeting of Stratford Town Council requesting the municipality ban cosmetic pesticides.] Comment

The future adoption of automation in weed control

Zheljana Peric / WeedsNews4717 / December 6, 2013 / 8:51:51 PM EST / 0 Comments
Abstract: The future adoption of automated weed control, either chemical or mechanical or otherwise, depends on a number of driving forces as well as on constraints that affect the diffusion of innovations. Some driving forces are the high labor requirements for weed control in organic agriculture, the development of herbicide resistance of weeds, and societal pressure for reduction of chemical use in agriculture and for traceability of cultivation practices. In addition, financial stimulation by government programs may accelerate acceptance. The constraints can be either technical in terms of working speed or reliability of technology, but also the relative age of existing chemical sprayers may slow down the diffusion. A number of examples of new technology introduction in agriculture are discussed to find similarities that can be a base for forecasting the adoption rate. We find some of the constraints and drivers for technology adoption and also if and how these drivers and constraints were really effective or were surpassed by other social or behavioral phenomena. It is expected that during the initial phases of adoption of automated weed control, a number of technology advances will be made that can enhance the acceptability by farmers as well as the willingness to invest by manufacturers. A 20-year period for a substantial market share of automated weed control equipment is expected. [Josse De Baerdemaeker (2014). Automation: The Future of Weed Control in Cropping Systems, Springer, 221-234] Comment

Non-chemical weed control for different pavement types

Zheljana Peric / WeedsNews4716 / December 6, 2013 / 8:51:23 PM EST / 0 Comments
Abstract: The recent phaseout of herbicide use on public pavements in Flanders has triggered the development of alternative weed control strategies. Besides the search for effective non-chemical curative methods, there is also a need for strategies that prevent or reduce weed growth on pavements. In this study a paving experiment was set up under a rain shelter to investigate the effects of four construction factors on weed growth: joint filling material, joint width, organic pollution of the joint filling material and type of bedding layer. Paving mini-plots were oversown with a mixture of dominant, hard-to-control weed species found on pavements. The inhibitory effect on weeds was determined by examining initial weed density and weed coverage over a 2-year period. More weed growth was found in pavings with wide joints and organically polluted joint filling materials. High permeability of the bedding layer resulted in higher weed cover. The coarse-grained filling materials and the sodium silicate-enriched sand Dansand® were associated with less weed cover than the fine-grained filling materials. Our results show there is potential for preventing weed growth using suitable paving materials and appropriate high-standard construction and maintenance of pavements. [De Cauwer B, Fagot M, Beeldens A, Boonen E, Bulcke R & Reheul D (2013). Reduced weed growth with different paving constructions. Weed Research, online 20 Nov] Comment

Effective mechanical weed control in processing tomato: Seven years of results

Zheljana Peric / WeedsNews4714 / November 19, 2013 / 11:19:09 PM EST / 0 Comments
Abstract: Open-air crops are important in Spanish horticulture. The limited number of herbicide active ingredients in minor crops, the waste problem of polyethylene (PE) plastic mulch and the high prices of biodegradable plastics leave hand-weeding and mechanical weed control as the most viable weed control methods. Different tools have been tested in northern European countries but their performance remains unknown in the edaphoclimatic situation of southern Europe. The objective of this work was to test novel physical weed control methods on processing tomato in northeastern Spain compared with other effective control methods, i.e., plastic and paper mulches. A first sequence of field trials was established from 2005 to 2008 at Zaragoza (Spain) to select the best physical control methods out of flamer, torsion weeder, finger weeder, flex-tine harrow and brush hoe used alone or in combination. The best method was the brush hoe which was then compared from 2009 to 2011 with PE mulch, biodegradable plastic mulch and paper mulch. Flamer, flex-tine harrow, torsion weeder and finger weeder performed quite irregularly due to crusty soil conditions and needed additional tools or repeated treatments to increase weed control efficacy. The brush hoe performed best in this soil situation working at about 5 cm depth. Weed biomass reduction was higher than 80% in 6 out of 7 years and similar yield was obtained in the brushed plots compared to the yield obtained with PE, biodegradable plastic and paper mulch. The brush hoe is thus a suitable option for weed control in processing tomato while the other tools were too weak to control aggressive summer weeds in the tested conditions. [A. Cirujeda c1, J. Aibar, M.M. Moreno and C. Zaragoza (2013). Effective mechanical weed control in processing tomato: Seven years of results Renewable Agriculture and Food Systems, online 08 October] Comment

Non-chemical weed control strategies for concrete block pavements

Zheljana Peric / WeedsNews4707 / November 15, 2013 / 10:27:18 PM EST / 0 Comments
Abstract: Reduction in herbicide use in non-agricultural areas is being imposed by a growing number of governments, triggering the development of alternative strategies for weed prevention and control. This study aimed to determine the weed preventive abilities of different paving types, the required treatment frequency of non-chemical weed control scenarios on these pavements and the associated weed species composition. A test parking area, constructed with four concrete paving types, was sown with a mixture of dominant weed species. Six scenarios with repeated use of a single weed control method (brushing with waste removal, hot air, selective application of hot water and three scenarios with flaming) and two scenarios with alternating use of brushes and hot air were applied to control the weeds during two growing seasons. Treatments were applied at well-defined intervention moments, based upon weed development. Over 2 years, the paving types differed in weed coverage (up to a fourfold difference) and required varying treatment frequency (up to a 11-fold difference) with lowest values for pavings with porous pavers. Within most paving types, up to 28% lower treatment frequencies were found for selective application of hot water, as compared with all other single method scenarios. Shifts in weed composition occurred in plots treated repeatedly with the same technique. Paving type determined the chances for the establishment of different weed species and alternating non-chemical control methods with different modes of action offered the best opportunity to keep weeds under control. [De Cauwer B, Fagot M, Beeldens A, Boonen E, Bulcke R & Reheul D (2013). Integrating preventive and curative non-chemical weed control strategies for concrete block pavements. Weed Research, on-line 31 Oct.] [Photo credit: Weedtechnics] Comment

Chemical solutions to herbicide resistance increase resistance

Zheljana Peric / WeedsNews4704 / November 15, 2013 / 9:43:48 PM EST / 0 Comments
[Michigan State University Extension 07 Nov 2013 by Diane Brown] — Herbicide-resistant weeds are becoming a more widespread problem in the United States. Although herbicide resistance has most commonly occurred in the south in cotton and soybeans, it is increasing in other regions as well. According to a team of agricultural researchers from Pennsylvania State University, University of New Hampshire and Montana State University, too much reliance on glyphosate-type herbicides for weed control on U.S. farms has created a dramatic increase in the number of genetically-resistant weeds. "I’m deeply concerned when I see figures that herbicide use could double in the next decade,” said David Mortensen, professor of weed ecology at Penn State. “During the period since the introduction of glyphosate-resistant crops, the number of weedy plant species that have evolved resistance to glyphosate has increased dramatically.” Mortensen said. This list includes many of the most problematic weed species, such as common ragweed, horseweed, johnsongrass and several of the most common pigweeds. According to the research team, despite company-sponsored research that indicated resistance would not occur, 21 different weed species have evolved resistance to several glyphosate herbicides, 75 percent of which have been documented since 2005. Read more …

Australian National Parks Service under pressure to stop aerial spraying

Zheljana Peric / WeedsNews4700 / November 12, 2013 / 11:01:16 PM EST / 0 Comments
[ABC News 8 Aug 2013] — A group of concerned Byron residents want to stop aerial spraying of herbicides by the NSW National Parks and Wildlife Service in the Tyagarah Nature Reserve. The Byron Shire Chemical Free Land Care group along with concerned residents stopped the spraying operation earlier this week by entering the dunes. The National Parks and Wildlife Service wanted to spray the site to remove the weed, bitou bush. Concerned resident, Iris Ray Nunn, said chemicals harm the environment and pose a threat to people who use the Nature Reserve. "The possible long term effects on the butterflys, the bees, the people who come there and the children who are playing in the sand," she said. "It stays in the ground for hundreds of days and that's quite alarming." Ms Nunn said people walk through the bush not realising it has just been sprayed with chemicals. "They sprayed the Cape and we watched the National Parks and Wildlife do that with a helicopter," she said. "It happened within half an hour period and then the Lighthouse is opened up again and really if you walked through there that morning you would be none the wiser that that had actually just happened." Comment

Stacked crop rotations exploit weed-weed competition for sustainable weed management

Zheljana Peric / WeedsNews4697 / November 11, 2013 / 10:56:54 PM EST / 0 Comments
Abstract: Crop rotation has long been considered one of the simplest and most effective tools for managing weeds. In this paper, we demonstrate how crop rotations can be strategically arranged to harness a novel mechanism of weed suppression: weed-weed competition. Specifically, we consider how crop stacking, or increasing the number of consecutive plantings of a single crop within a rotation, can decrease the size of the weed seed bank, by forcing weeds to compete with each other in similar environments for longer periods of time, while still reaping the traditional benefits of crop rotation. Using an annual plant model, we investigate the theoretical effects of stacked crop rotations on weeds that have different life-history strategies and phenology. Our results show that when weeds compete within a season, stacking can reduce the weed seed bank compared to rotations without stacked crops. Although more research is needed to fully understand the effects of crop stacking on other aspects of the system, such as insect pests and diseases, our research suggests that crop stacking has the potential to improve weed suppression without additional inputs, and their associated costs and externalities. More generally, improving management by changing the temporal arrangement of disturbances is a novel, process-based approach that could likely be applied to other weed management practices, such as mowing, and which could involve mechanisms other than weed-weed competition. Leveraging this new application of existing ecological theory to improve weed management strategies holds great promise. [Andrew J. Garrison, Adam D. Miller, Matthew R. Ryan, Stephen H. Roxburgh, and Katriona Shea (2013). Stacked crop rotations exploit weed-weed competition for sustainable weed management. Weed Science, on-line Aug 27.] Comment

Herbicides linked to developmental abnormalities in Pacific Oysters

Zheljana Peric / WeedsNews4695 / November 10, 2013 / 10:33:22 PM EST / 0 Comments
Abstract: Irgarol and diuron are the most representative “organic booster biocides” that replace organotin compounds in antifouling paints, and metolachlor is one of the most extensively used chloroacetamide herbicides in agriculture. The toxicity of S-metolachlor, irgarol and diuron was evaluated in Pacific oyster (Crassostrea gigas) gametes or embryos exposed to concentrations of pesticides ranging from 0.1× to 1000×, with 1× corresponding to environmental concentrations of the three studied pesticides in Arcachon Bay (France). Exposures were performed on (1) spermatozoa alone (2) oocytes alone and (3) both spermatozoa and oocytes, and adverse effects on fertilization success and offspring development were recorded. The results showed that the fertilizing capacity of spermatozoa was significantly affected after gamete exposure to pesticide concentrations as low as 1× of irgarol and diuron and 10× of metolachlor. The offspring obtained from pesticide-exposed spermatozoa displayed a dose-dependent increase in developmental abnormalities. In contrast, treating oocytes with pesticide concentrations up to 10× did not alter fertilization rate and offspring quality. However, a significant decline in fertilization success and increase in abnormal D-larvae prevalence were observed at higher concentrations 10× (0.1 μg L−1) for S-metolachlor and 100× for irgarol (1.0 μg L−1) and diuron (4.0 μg L−1). Irgarol, diuron and S-metolachlor also induced a dose-dependent increase in abnormal D-larvae prevalence when freshly fertilized embryos were treated with pesticide concentrations as low as concentration of 1× (0.01 μg L−1 for irgarol or S-metolachlor, and 0.04 μg L−1 for diuron). The two bioassays on C. gigas spermatozoa and embryos displayed similar sensitivities to the studied pesticides while oocytes were less sensitive. Diuron, irgarol and S-metolachlor induced spermiotoxicity and embryotoxicity at environmentally relevant concentrations and therefore might be a threat to oyster recruitment in coastal areas facing chronic inputs of pesticides.[Huong Mai, Bénédicte Morin, Patrick Pardon, Patrice Gonzalez, Hélène Budzinski & Jérôme Cachot (2013). Environmental concentrations of irgarol, diuron and S-metolachlor induce deleterious effects on gametes and embryos of the Pacific oyster, Crassostrea gigas. Marine Environmental Research, 89, 1–8] Comment

Woody weeds can be used for biochar

Zheljana Peric / WeedsNews4691 / November 10, 2013 / 10:00:26 PM EST / 0 Comments
[ABC Rural 6 Nov 2013 by Matt Brann] — Australia's Northern Territory has some of the world's largest plantations of African Mahogany and Indian sandalwood, as well as thousands of hectares of country infested with woody weeds - all of which could contribute to an emerging biochar industry. Known as a "carbon sponge", biochar is essentially charcoal, and is created by converting biomass into a charred product under oxygen-limited conditions (in a reactor). Designed to improve the efficiency of water and fertiliser use in soils, the product is being trialled in the Northern Territory for the first time and showing some excellent results. Environmental scientist, Azain Raban, says zucchini yields on a farm near Darwin have increased by 25 per cent thanks to biochar (applied at a rate of 25 tonnes to the hectare). He says the product has a big future in northern agriculture, but producing biochar locally is the key to its viability. "Having a (biochar) machine in the Territory to utilise woody waste will be the key to its success, because it'll make it cost-effective by reducing transport costs," he said. "I think the plantations in the NT will produce large quantities of waste-wood, which can be utilised for biochar production." The most likely candidates for biochar production include host trees from the Indian sandalwood industry, and trees which have been "thinned" out of mahogany plantations. Azain Raban says woody weeds such as mimosa, could also be used to create local biochar. "Woody weeds are a huge problem in the Territory, and because we now have mobile biochar machines, you could take the machine to where the weeds are and utilise them on site." Mr Raban says a lot woody weeds and waste from plantations are currently burnt, and says turning them into biochar is a much better outcome. "If we turn it into biochar instead of just burning it, we avoid the release of carbon dioxide and other toxic emissions associated (with burning)," he said. "We are instead utilising the biomass and producing carbon that actually contributes to soil productivity and plant productivity... so it closes the loop." [Photo credit: Earth Systems Bioenergy] Comment

Experts agree that GM food safety claims are misleading

Zheljana Peric / WeedsNews4681 / October 29, 2013 / 9:31:16 PM EST / 0 Comments
There is no scientific consensus on the safety of genetically modified foods and crops, according to a statement released by an international group of more than 90 scientists, academics and physicians. The statement comes in response to recent claims from the GM industry and some scientists, journalists, and commentators that there is a “scientific consensus” that GM foods and crops were generally found safe for human and animal health and the environment. The statement calls these claims “misleading”, adding, “This claimed consensus on GMO safety does not exist.” "Such claims may place human and environmental health at undue risk and create an atmosphere of complacency," states Dr. Angelika Hilbeck, chairperson of the European Network of Scientists for Social and Environmental Responsibility (ENSSER) and one of the signatories. “The statement draws attention to the diversity of opinion over GMOs in the scientific community and the often contradictory or inconclusive findings of studies on GMO safety. These include toxic effects on laboratory animals fed GM foods, increased pesticide use from GM crop cultivation, and the unexpected impacts of Bt insecticidal crops on beneficial and non-target organisms,” Dr Hilbeck continues. In spite of this nuanced and complex picture, a group of like-minded people makes sweeping claims that GM crops and foods are safe. In reality, many unanswered questions remain and in some cases there is serious cause for concern. Read more ….

Linking pesticide exposure and dementia: What is the evidence?

Zheljana Peric / WeedsNews4679 / October 29, 2013 / 8:53:51 PM EST / 0 Comments
Abstract: There has been a steep increase in the prevalence of dementia in recent decades, which has roughly followed an increase in pesticide use some decades earlier, a time when it is probable that current dementia patients could have been exposed to pesticides. This raises the question whether pesticides contribute to dementia pathogenesis. Indeed, many studies have found increased prevalence of cognitive, behavioral and psychomotor dysfunction in individuals chronically exposed to pesticides. Furthermore, evidence from recent studies shows a possible association between chronic pesticide exposure and an increased prevalence of dementia, including Alzheimer's disease (AD) dementia. At the cellular and molecular level, the mechanism of action of many classes of pesticides suggests that these compounds could be, at least partly, accountable for the neurodegeneration accompanying AD and other dementias. For example, organophosphates, which inhibit acetylcholinesterase as do the drugs used in treating AD symptoms, have also been shown to lead to microtubule derangements and tau hyperphosphorylation, a hallmark of AD. This emerging association is of considerable public health importance, given the increasing dementia prevalence and pesticide use. Here we review the epidemiological links between dementia and pesticide exposure and discuss the possible pathophysiological mechanisms and clinical implications of this association. [Ioannis Zaganas, Stefania Kapetanaki, Vassileios Mastorodemos, Konstantinos Kanavouras, Claudio Colosio, Martin F. Wilks & Aristidis M. Tsatsakis (2013). Linking pesticide exposure and dementia: What is the evidence? Toxicology, 307, 3–11] Comment

Commercial formulation of herbicide found to be more toxic than pure active ingredient

Zheljana Peric / WeedsNews4677 / October 28, 2013 / 10:33:40 PM EST / 0 Comments
Abstract: The in vitro effects of S-metolachlor and its formulation Twin Gold Pack® (96% a.i.) were evaluated in human hepatoma (HepG2) cells. Cytokinesis-blocked micronucleus cytome (CBMN-cyt) and MTT assays as well as Neutral Red uptake were employed for genotoxicity and cytotoxicity evaluation. Activities were tested within the concentration range of 0.25–15 μg/ml S-metolachlor for 24 h of exposure. Both compounds rendered a minor reduction in the NDI although not reaching statistical significance. Results demonstrated that the S-metolachlor was not able to induce MNs. On the other hand, 0.5–6 μg/ml Twin Pack Gold® increased the frequency of MNs. When cytotoxicity was estimated, S-metolachlor was not able to induce either a reduction of lysosomal or mitochondrial activity. Contrarily, whereas 1–15 μg/ml Twin Pack Gold® induced a significant reduction of mitochondrial activity, all tested concentrations of the formulated product induced a significant decrease of lysosomal performance as a function of the concentration of the S-metolachlor-based formulation titrated into cultures. Genotoxicity and cytotoxicity differences obtained with pure S-metolachlor and the commercial S-metolachlor-based formulation indicate that the latter may contain additional unsafe xenobiotics and support the concept of the importance of evaluating not only the active principle but also the commercial formulation when estimating the real hazard from agrochemicals. [Noelia Nikoloffa, Luciana Escobara, Sonia Soloneskia & Marcelo L. Larramendy (2013). Comparative study of cytotoxic and genotoxic effects induced by herbicide S-metolachlor and its commercial formulation twin gold pack® in human hepatoma (HepG2) cells. Food and Chemical Toxicology, online 18 Oct 2013] Comment

Dutch organic sales up 16.4% to reach €1bn milestone

Zheljana Peric / WeedsNews4675 / October 28, 2013 / 9:50:03 PM EST / 0 Comments
[Fruitnet 11 Oct 2013] — Total consumer spending on organic food in the Netherlands passed the €1bn in 2012, according to a new report by Dutch organic chain organisation Bionext. The study, which was commissioned by the Dutch Ministry of Economic Affairs, found that most organic food was sold in conventional supermarkets, health food stores and through the 'out of home' channel. Farmers markets and local stores sold around €70.1m of organic food, helping the total hit the €1bn mark, with overall spending on organic fruit and vegetables increasing 16.4 per cent compared with 2011. "The non-stop rise of organic sales during the economic crisis is a clear signal to the industry that consumers are fed up with food production that only benefits shareholders, but harms the environment, society's social fabric and your health," noted Eosta CEO Volkert Engelsman. "Consumers ask for sustainability and transparency, which is why we developed the Nature & More transparency scheme," he added. "Transparency empowers consumers to make informed purchase decisions – that creates trust." Comment

Local council uses goats to manage weeds in wetland

Zheljana Peric / WeedsNews4672 / October 28, 2013 / 9:26:46 PM EST / 0 Comments
[Merimbula News 28 Oct 2013] — Volunteers at Panboola Wetlands in NSW Australia have worked hard to remove weeds and have been assisted by Council in their efforts to eradicate dense infestations, but now the wetlands is getting help from a completely different source – goats. Bega Valley Shire’s weeds and vegetation manager, Ann Herbert, said: “In recent weeks council vegetation officers have overseen a different weed control program, using goats to control blackberry, privet, honeysuckle and other woody weeds on an area of Crown Land within the wetlands. “The goats have stripped the area of small trees, shrubs, low hanging branches and enjoyed lopped tree branches. The area was effectively cleared for officers to get in and cut the bigger trees, many of which have been ring-barked by the goats. Branches and fallen trees have been stockpiled for disposal,” said Ms Herbert. Further weed control will continue in the next twelve months with indigenous trees and shrubs to be planted in autumn 2014. “It is proving a very successful project and a great example of how community and council can work together,” said Ms Herbert. For more information on weed management using goats contact Bega Shire Council on +61 2 6499 2222. Comment

First pesticide-residue-free certification appears on lettuce labels

Zheljana Peric / WeedsNews4669 / October 28, 2013 / 8:43:07 PM EST / 0 Comments
[Packaging Digest 10 Oct 2013] — United States produce industry leader, Tanimura & Antle has had its greenhouse grown butter lettuce independently certified as Pesticide Residue Free. Lettuce packages will feature a new certification mark alerting shoppers to this unique product benefit. Tanimura & Antle is the first to obtain this certification for greenhouse grown lettuce. "Our greenhouse operation uses minimal controls in the growing cycle, as the growing environment is closed and generally pest free," according to Diana McClean, director of marketing for Tanimura & Antle. "This certification independently assures consumers that our greenhouse grown lettuce does not have pesticide residue." The Pesticide Residue Free certification is conducted by Emeryville, California-based SCS Global Services (SCS), a third-party certifier of environmental, sustainability and food safety claims. The SCS assessment process screens for high risk pesticides, predicts critical stages in the spraying and harvesting cycle, and tests the final product to ensure that the produce is free of pesticide residues, based on the strict limit-of-detection standard of 0.01 ppm or less. For more information about the program, go to To see othePackaged year-round from their Livingston, TN, greenhouse, Tanimura & Antle Hydroponic Butter lettuce is available in a 1-count clamshell and a 3-count club-pack at retail stores across the United States. Comment

Herbicides killing Great Barrier Reef seagrasses

Zheljana Peric / WeedsNews4663 / October 8, 2013 / 5:49:42 PM EST / 0 Comments
Abstract: Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zostera muelleri and Halodule uninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/Fm′), indicating reduced photosynthesis and maximum effective yields (Fv/Fm) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows of the GBR from further decline. [Flores F, Collier C J, Mercurio P, Negri A P (2013). Phytotoxicity of four photosystem II herbicides to tropical seagrasses. PLoS ONE 8(9): e75798. doi:10.1371/journal.pone.0075798] Comment

Increase in alien plant invasions primarily a result of increased application of chemical fertilizer and herbicides

Zheljana Peric / WeedsNews4660 / October 1, 2013 / 10:13:40 PM EST / 0 Comments
Abstract: Arable areas are commonly susceptible to alien plant invasion because they experience dramatic environmental influences and intense anthropogenic activity. However, the limited reports on relevant factors in plant invasion of croplands have addressed single or a few invasive species and environmental factors. To elucidate key factors affecting plant invasions in croplands, we analyzed the relationship between 11 effective factors and changes in composition of alien plants, using field surveys of crop fields in Anhui Province conducted during 1987–1990 (historical dataset) and 2005–2010 (recent dataset), when rapid urbanization was occurring in China. We found that in the past few decades, the dominance and richness of alien plant populations approximately doubled, despite differences among the 4 regions of Anhui Province. Among the 38 alien invasive plant species observed in the sites, the dominance values of 11 species increased significantly, while the dominance of 4 species decreased significantly. The quantity of chemical fertilizer and herbicide applied, population density, agricultural machinery use, traffic frequency, and annual mean temperature were significantly related to increased richness and annual dominance values of alien plant species. Our findings suggest that the increase in alien plant invasions during the past few decades is primarily a result of increased application of chemical fertilizer and herbicides. [Chen G-Q, He Y-H, Qiang S (2013). Increasing seriousness of plant invasions in croplands of Eastern China in relation to changing farming practices: A case study. PLoS ONE 8(9): e74136. doi:10.1371/journal.pone.0074136] Comment

Pesticides harm reproductive health warn American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine

Zheljana Peric / WeedsNews4657 / October 1, 2013 / 10:00:45 PM EST / 0 Comments
Abstract: Reducing exposure to toxic environmental agents is a critical area of intervention for obstetricians, gynecologists, and other reproductive health care professionals. Patient exposure to toxic environmental chemicals and other stressors is ubiquitous, and preconception and prenatal exposure to toxic environmental agents can have a profound and lasting effect on reproductive health across the life course. Prenatal exposure to certain chemicals has been documented to increase the risk of cancer in childhood; adult male exposure to pesticides is linked to altered semen quality, sterility, and prostate cancer; and postnatal exposure to some pesticides can interfere with all developmental stages of reproductive function in adult females, including puberty, menstruation and ovulation, fertility and fecundity, and menopause. Many environmental factors harmful to reproductive health disproportionately affect vulnerable and underserved populations, which leaves some populations, including underserved women, more vulnerable to adverse reproductive health effects than other populations. The evidence that links exposure to toxic environmental agents and adverse reproductive and developmental health outcomes is sufficiently robust, and the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine join leading scientists and other clinical practitioners in calling for timely action to identify and reduce exposure to toxic environmental agents while addressing the consequences of such exposure. A chemical should never be released if a concern exists regarding its effect on health. Comment

Targeted grazing for weed control proves more cost-effective than herbicides

Zheljana Peric / WeedsNews4652 / October 1, 2013 / 9:10:46 PM EST / 0 Comments
Abstract: Our objective was to evaluate the cost/benefit of a single herbicide application or targeted grazing of invasive annual grasses during restoration of partially invaded sagebrush steppe ecosystems used for livestock production. The cost/benefit model used is based on estimating the production of vegetation in response to implementing management and modeling cost/benefit economics associated with that prediction. The after-tax present value of added animal unit months (AUMs) obtained was lower than the present value of after-tax treatment costs after 20 yr for a single herbicide treatment, but higher than the present value of after-tax treatment costs for the grazing management scenario. Even at the highest weed utilization level, the value of added AUMs did not offset the cost of the treatment after 20 yr. However, the grazing treatment resulted in a value of added AUMs higher than the costs after 20 yr. Depending on the invasive weed utilization level, break-even points with targeted grazing occurred at anywhere from the first year to 7 yr. This assessment clearly shows that grazing management can be economically viable for managing annual grass-infested rangeland. In the future, models like the one used here can be improved by incorporating the rangeland management and restoration benefits on the wide variety of goods and services gained from rangeland. [Roger Sheley, Jordan Sheley, and Brenda Smith (2013). Cost/Benefit Analysis of Managing Invasive Annual Grasses in Partially Invaded Sagebrush Steppe Ecosystems. Weed Science, on line Sept 26. dx.doi.org/10.1614/WS-D-13-00056.1] Comment

Keywords: Restoration cost/benefit, grazing, herbicides, invasive annual grasses

Original source

Smart mouldboard ploughing improves weed management

Zheljana Peric / WeedsNews4649 / September 30, 2013 / 10:15:39 PM EST / 0 Comments
[The Australian Dairy Farmer 23 July 2013] — MOULDBOARD ploughing has not only helped overcome non-wetting soils for Mingenew farmer, Stuart Smart, but also proved an effective non-chemical weed control. Mouldboard ploughing has increased yield by up to 0.4 tonnes per hectare in spot trials on Mr Smart’s property, as well as controlling up to 95 per cent of weeds in the first year of use.“ For us it has been a total turnaround. We’ve gone from soil that wouldn’t accept water at all to fully wet soil,” Mr Smart said. “For weed management, where we once payed $120 per hectare for chemical with no effective control, we now pay $70-90 for mouldboard ploughing.” Mr Smart crops 14,000ha of his 22,000ha property south-east of Mingenew in the Mid-West region of Western Australia. Growing season rainfall has varied greatly in recent years, but is traditionally between 300-350mm. Mr Smart said they began mouldboard ploughing four years ago using a 14-furrow plough with the aim being to completely invert the soil. Over the years he has refined the system and this year had two ploughs running around the clock for selected paddocks. “The point of mouldboard ploughing for us is to invert all of the non-wetting soil and any weed seed, placing between 6-8 inches of clean sand over the top,” Mr Smart said. “Now if we get 5mm of rain, the soil is wet from the top through to its maximum point of extension and our weed control has improved dramatically.” Ryegrass is the main problem weed, with increasing herbicide resistance meaning non-chemical treatments are essential to reduce weed populations. “We were running out of chemicals that we could use and we needed something that allowed us to regain control of the situation,” Mr Smart said. “This year we’ve had great results. The 300-400ha of soil that we’ve re-inverted after two years hasn’t brought any ryegrass back up and only a small amount of wild radish has reappeared.” “We haven’t experienced any adverse effects and only found positives. Last year this was highlighted by a ploughed and non-ploughed crop sitting side-by-side in a small trial we did with the header, and the treated patch outperforming its neighbour 2.4t/ha to 2t/ha. “With a return on investment like that, it really is a no-brainer for our operation. Comment

Allelopathic effects of three plant invaders on germination of native species: a field study

Zheljana Peric / WeedsNews4648 / September 30, 2013 / 9:47:17 PM EST / 0 Comments
Abstract: The ability of some invasive plant species to produce biochemical compounds toxic to native species, called allelopathy, is thought to be one of the reasons for their success when introduced to a novel range, an idea known as the Novel Weapons Hypothesis. However, support for this hypothesis mainly comes from bioassays and experiments conducted under controlled environments, whereas field evidence is rare. In a field experiment, we investigated whether three plant species invasive in Europe, Solidago gigantea, Impatiens glandulifera and Erigeron annuus, inhibit the germination of native species through allelopathy more than an adjacent native plant community. At three sites for each invasive species, we compared the germination of native species that were sown on invaded and non-invaded plots. Half of these plots were amended with activated carbon to reduce the influence of potential allelopathic compounds. The germination of sown seeds and of seeds from the seedbank was monitored over a period of 9 weeks. Activated carbon generally enhanced seed germination. This effect was equally pronounced in invaded and adjacent non-invaded plots, indicating that invasive species do not suppress germination more than a native plant community. In addition, more seeds germinated from the seedbank on invaded than on non-invaded soil, probably due to previous suppression of germination by the invasive species. Our field study does not provide evidence for the Novel Weapons Hypothesis with respect to the germination success of natives. Instead, our results suggest that if invasive species release allelopathic compounds that suppress germination, they do so to a similar degree as the native plant community. [Corina Del Fabbro, Sabine Güsewell, Daniel Prati (2013). Allelopathic effects of three plant invaders on germination of native species: a field study. Biological Invasions, DOI 10.1007/s10530-013-0555-3] Comment

The use of goat grazing to restore pastures invaded by shrubs and avoid desertification

Zheljana Peric / WeedsNews4643 / September 20, 2013 / 10:27:49 PM EST / 0 Comments
Abstract: Spanish mountains have been affected by the expansion of shrubs and forests since the mid-20th century. This secondary succession in vegetation has some positive effects, but also drawbacks, such as an increase in fire risk, loss of diversity in land use, a reduction in landscape and cultural value, less water available in river channels and reservoirs, constraints on livestock farming, a reduced number of local species and loss of biodiversity. This paper analyses the potential for grazing domestic goats to help control the spread of several species of shrubs such as the common broom (Cytisus scoparius), red raspberry (Rubus idaeus) and roses (Rosa sp.) that are commonly found in degraded pastures in the Cantabrian Mountains of northern Spain. Using experimental plots, the effects of two levels of stocking density (4·5 and 9 goats ha−1 y−1) are compared with other land management systems used in the region: burning, mechanical clearing and trimming. The combined use of goats with support from burning, clearing and trimming controls the spread of shrubs. The most efficient treatment was found with nine goats ha−1 y−1. Goat grazing also changes the distribution of shrubs, transforming a dense and continuous coverage into separate clumps and thereby enabling livestock to graze more easily. Maintaining a mixed structure of shrubs and pastures is the best treatment due to the low population density of the Cantabrian Mountains, as this enhances the biodiversity, controls fire risk and enriches the landscape; it also allows extensive livestock grazing as a main economic resource. [Álvarez-Martínez, J., Gómez-Villar, A. and Lasanta, T. (2013). The use of goat grazing to restore pastures invaded by shrubs and avoid desertification: a preliminary case study in the Spanish Cantabrian mountains. Land Degrad. Dev. online 15 June, doi: 10.1002/ldr.2230] Comment

New genetically engineered crop will sharply increase use of toxic pesticide, a "Probable Human Carcinogen"

Zheljana Peric / WeedsNews4642 / September 20, 2013 / 9:42:01 PM EST / 0 Comments
[Center for Food Saftety 29 Aug 2013] — The U.S. Department of Agriculture has quietly approved the first of a new generation of GE crops resistant to more toxic herbicides. The first crop to pass the low regulatory bar was a Bayer soybean variety genetically engineered to withstand direct application of the herbicide isoxaflutole (IFT), which according to the Environmental Protection Agency (EPA) is a “probable human carcinogen.” Center for Food Safety (CFS) projects at least a four-fold rise (.PDF) in national use of this toxic herbicide thanks to these new GE soybeans, and a host of related human health and environmental harms. Additional scientific detail about this and other new GE crops can be found here. “Bayer’s new GE soybeans represent the next wave in agricultural biotechnology – crops that dramatically increase famers’ use of and dependence on toxic herbicides,” said Bill Freese, science policy analyst at Center for Food Safety. Dubbed FG72, these GE soybeans were developed by Bayer CropScience, the second-largest agrichemicals firm in the world. EPA has designated IFT as a “probable human carcinogen” based on animal tests in which it triggered liver and thyroid tumors in rats. IFT and its major breakdown product persist in surface waters, and despite its limited use at present is frequently detected in tests. It is also toxic to aquatic organisms, wild plants and important crops (e.g. vegetables.). IFT is so toxic that three states – Wisconsin, Michigan and Minnesota – rejected the Bayer-EPA label for this herbicide as insufficiently protective of human health, the environment, and neighboring crops. First generation GE crops, like Monsanto’s Roundup Ready (RR) varieties, are resistant to the herbicide glyphosate. Skyrocketing use of glyphosate with RR crops has wiped out biological diversity in our fields, for instance nearly wiping out milkweed and thereby contributing to a dramatic decline in Monarch butterfly populations. Glyphosate use has also triggered an epidemic of glyphosate-resistant weeds that now infest roughly half of farmers’ fields. “Bayer and other biotech companies are now poised to introduce a host of ‘next-generation’ GE crops resistant to more toxic herbicides as a false ‘solution’ to massive weed resistance. But their effect will be to generate still more intractable weeds resistant to multiple herbicides,” said Freese. “It’s ironic that supposedly ‘cutting-edge’ biotechnology is taking American agriculture a half-century and more backwards into a more toxic past,” continued Freese. Dow AgroSciences is awaiting USDA approval of 2,4-D-resistant corn and soybeans. 2,4-D is one of the oldest herbicides, introduced in the 1940s. It formed part of Agent Orange used in the Vietnam War, and has been linked by medical scientists to an often-fatal immune system cancer in farmers, among other adverse effects. “It’s not only Dow. The pipeline includes Monsanto soybeans and cotton resistant to dicamba, which was introduced in the 1960s, and similar crops from other biotech companies,” said Freese. “Don’t listen to the industry hype,” Freese concluded. “Biotechnology means toxic, unsustainable agriculture. We need to evolve our agriculture beyond antiquated, pesticide-promoting GE crops towards cutting-edge agroecological techniques for managing weeds instead of eradicating them. Organic agriculture is one path, low-input systems that minimize pesticide use is another.” For more detailed information on this newly approved crop, visit HERE. Comment

Novel ecosystems support substantial avian assemblages: the case of invasive alien Acacia thickets

Zheljana Peric / WeedsNews4640 / September 20, 2013 / 9:16:09 PM EST / 0 Comments
Abstract: Altered habitats may form entirely novel ecosystems that support new combinations of species. How indigenous species use invaded areas is, however, not well understood. Here, we investigate the value of Australian Acacia thickets as novel ecosystems in the Western Cape of South Africa by surveying bird assemblages within them. Location: Western Cape Province of South Africa. Methods: Birds were surveyed quantitatively in a variety of Acacia thickets in the south-western Western Cape in three seasons to examine species richness, abundance and functional diversity. We also examined the extent to which avian diversity was related to differences in patch-level vegetation structure. Results: Significant variation was observed in assemblage richness, density and biomass across sites. Diversity increased with productivity, but declined with stem density and canopy cover. On average, Acacia thicket patches were used by c. 20 species (with a regional richness of 76 species), had a mean density of 7.78 birds ha−1 and a mean biomass of 0.224 kg ha−1. The most abundant feeding guilds were the mixed feeders and insectivores. Main conclusion: Acacia thickets in the Western Cape support a large subset of the region's birds with the most abundant species being small mixed feeders. Compared with other habitat types, Acacia thickets support avian assemblages with species richness and density similar to some natural sites in the region, but lacking typical nectarivores. Extrapolation to the area transformed by invasive acacias in the Cape Floristic Region suggests that these novel ecosystems support c. 22 million individual birds or 621 tonnes of avian biomass. [Andrew M. Rogers, Steven L. Chown (2013). Novel ecosystems support substantial avian assemblages: the case of invasive alien Acacia thickets. Diversity & Distributions, online 06 Sept.] Comment

Integration of allelopathy to control weeds in rice

Zheljana Peric / WeedsNews4639 / September 20, 2013 / 9:19:33 AM EST / 0 Comments
Rice (Oryza sative L.) is the main food crop in Asia and the staple food of the majority of the population in many regions of the world. The population pressure in rice-consuming countries demands that more attention be directed towards new approaches to sustainable rice produc‐ tion. Improvement of both crop quality and yield is an urgent task [1]. Optimally, rice yield improvement must be sought through agronomic approaches that are environmentally safe [2]. Weed management using allelopathy may effect a yield improvement without environ‐ mental cost, which is one of the most important considerations for worldwide scientists working to secure the world’s food supply for future generations. Allelopathy is described as the ability of plants to inhibit or stimulate growth of other plants in the environment by exuding chemicals. The overuse of agrochemicals has caused environmental degradation, pest tolerance and human health concerns. Agriculture worldwide is currently using about 3 million tons of herbicides annually, and herbicide-resistant weeds have become more prolific, which has further expanded the use of herbicides [8]. To solve these problems, it is necessary to develop sustainable weed management systems that may reduce both herbicide dependency and the burden of manual weeding. With attempts to exploit rice’s allelopathic properties for weed control in rice growing, research into rice allelopathy was begun in the early 1970s and has been widely studied in the USA, Europe, Japan, Korea, India and China. If the allelopathic property of crops can be improved, it implies that the competitive ability of crops against weeds can be strengthened, the amount of applied herbicides lowered and environmental risks reduced. Improved crops’ allelopathic potential may be useful for rice and all other crops [9]. Crop allelopathy may be a successful tool to manage weed infestations in agricultural production, if it can be exploited appropriately in a rotational cropping system [10]. However, in the case of rice, it is difficult to rotate different crops in a paddy field; therefore, enhancing weed suppression by rice itself may be among the most feasible means of controlling weeds. [ Khanh, T.D.Linh, L.H. Linh, T.H. Quan, N.T., Cuong, D.M., Hien, V.T.T., Ham, L.H. Trung, K.H. and Xuan,T.D. (2013). Integration of allelopathy to control weeds in rice. Ch. 4:75-99. In Herbicides - Current Research and Case Studies in Use. dx.doi.org/10.5772/56035] Comment

Comparative life cycle assessment in the wine sector: Biodynamic vs. conventional viticulture activities in NW Spain

Zheljana Peric / WeedsNews4637 / September 10, 2013 / 10:24:58 PM EST / 0 Comments
Abstract: Viticulture is currently experiencing a gradual shift to more sustainable production practices. Many producers see in this shift an opportunity to increase their sales, especially in a context which is greatly influenced by the reduction in wine sales due to the world economic crisis. Hence, both organic and biodynamic viticulture have begun to be applied in many vineyards as alternative attractive agricultural techniques. Nevertheless, it remains unclear which are the exact environmental benefits (or drawbacks) of applying these techniques for numerous environmental impacts, such as climate change or toxicity. Therefore, the main goal of this study is to perform an environmental evaluation using Life Cycle Assessment (LCA) for three different viticulture techniques within a single appellation (Ribeiro, NW Spain): biodynamic cultivation sites, conventional vineyards and an intermediate biodynamic-conventional wine-growing plantation (i.e. biodynamic site lacking certification). Moreover, two methodological improvements in the field of wine LCA studies are suggested and developed in terms of land use impact categories and labour inclusion in life-cycle thinking. Results demonstrate that biodynamic production implies the lowest environmental burdens, and the highest environmental impacts were linked to conventional agricultural practices. The main reasons for this strong decrease in environmental impacts for the biodynamic site is related to an 80% decrease in diesel inputs, due to a lower application of plant protection products and fertilisers, and the introduction of manual work rather than mechanised activities in the vineyards. [Pedro Villanueva-Reya, Ian Vázquez-Roweb, M Teresa Moreiraa, Gumersindo Feijooa (2013). Comparative life cycle assessment in the wine sector: Biodynamic vs. conventional viticulture activities in NW Spain. Journal of Cleaner Production, online 30 Aug] Comment

Durum wheat and allelopathy: towards wheat breeding for natural weed management

Zheljana Peric / WeedsNews4635 / September 9, 2013 / 9:08:03 PM EST / 0 Comments
Abstract: Wheat-derived foodstuffs represent about one-fifth of the calories consumed by humans worldwide. Bread wheat (Triticum aestivum L.) is one of the most important crops throughout the world, and it has been extensively studied for its allelopathic potential. In contrast, for allelopathy in durum wheat (Triticum turgidum ssp. durum), our knowledge is partial and fragmentary. Through highlighting recent advances in using allelopathy as a crop breeding tool, we provide an overview of allelopathy in Triticum spp., to stimulate further coordinated breeding-oriented studies, to favour allelopathy exploitation for the sustainable cultivation of wheat, and in particular, to achieve improved biological weed control. [Mariagiovanna Fragasso, Anna Iannucci and Roberto Papa (2013). Durum wheat and allelopathy: towards wheat breeding for natural weed management. Front. Plant Sci. 4:375]

Coalition of 250 groups demand USA's EPA ban atrazine to protect human health and wildlife

Zheljana Peric / WeedsNews4633 / September 5, 2013 / 10:50:12 PM EST / 0 Comments
[Centre for Biological Diversity 26 Aug 2013] WASHINGTON - A diverse coalition of over 250 conservation, public-health and sustainable farming groups sent a letter asking the U.S. Environmental Protection Agency to ban atrazine, a toxic pesticide that threatens wildlife and people across the country. The Center for Biological Diversity also submitted comments from more than 38,000 people asking the EPA to immediately stop use of this endocrine-disrupting poison in the United States. “We need to get this dangerous pesticide out of our water supply before it does any more damage,” said Collette Adkins Giese, a Center biologist and lawyer who works to save imperiled amphibians and reptiles. “It’s pretty obvious that a pesticide that chemically castrates male frogs is highly suspect for people too, as well as bad for other wildlife. It certainly shouldn’t be showing up in our drinking water.” Although the pesticide is banned in the European Union, up to 80 million pounds of it are used in the United States each year, contaminating ground, surface and drinking water. Atrazine, or its primary degradate, was found in approximately 75 percent of stream water and about 40 percent of all groundwater samples from agricultural areas tested in an extensive U.S. Geological Survey study. Amphibians are particularly vulnerable to pesticide impacts because they live in waterways where their permeable skins absorb contaminants from agricultural runoff. Dr. Tyrone Hayes at the University of California has shown that atrazine chemically castrates and feminizes male frogs at concentrations lower than the level allowed in drinking water by the EPA. In people, atrazine exposure may be linked to increased risks of thyroid cancer, reproductive harm and birth defects. For example, a recent study showed that children of mothers exposed to atrazine had an increased risk of a birth defect called choanal atresia, a narrowing or blockage of the back of the nasal canal that can be life-threatening in newborn infants.The coalition's letter calls upon the EPA to ban atrazine due to “widespread exposure and unreasonable risks to human health and the environment.” The agency received today’s letter, and thousands of comments calling for an atrazine ban, during the public comment period opened for the agency’s “registration review” of the chemical. The EPA also received technical comments on the need to protect endangered species from the dangers of atrazine. Comment

Comparison of organic and conventional managements on yields, nutrients and weeds in a corn–cabbage rotation

Zheljana Peric / WeedsNews4631 / September 5, 2013 / 10:05:01 PM EST / 0 Comments
Abstract: Conventional soil management systems (SMS) use synthetic inputs to maximize crop productivity, which leads to environmental degradation. Organic SMS is an alternative that is claimed to prevent or mitigate such negative environmental impacts. Vegetable production systems rely on frequent tillage to prepare beds and manage weeds, and are also characterized by little crop residue input. The use of crop residues and organic fertilizers may counteract the negative impacts of intensive vegetable production. To test this hypothesis, we evaluated the effect of sweet corn (Zea mays L. var. rugosa) residue incorporation in a corn–cabbage (Brassica oleracea L.) rotation on crop yields, nutrient uptake, weed biomass and soil nutrients for organic and conventional SMS in two contrasting soil types (a Chromosol and a Vertosol). Yields of corn and cabbage under the organic SMS were not lower than the conventional SMS, possibly due to the equivalent N, P and K nutrients applied. Macro-nutrient uptake between the organic and conventional SMS did not differ for cabbage heads. Corn residue incorporation reduced the average in-crop weed biomass in cabbage crops by 22% in 2010 and by 47% in 2011. Corn residue-induced inhibitions on weed biomass may be exploited as a supplementary tool to mechanical weed control for the organic SMS, potentially reducing the negative impacts of cultivation on soil organic carbon. Residue incorporation and the organic SMS increased the average total soil N by 7 and 4% compared with the treatments without residue and the conventional SMS, respectively, indicating the longer-term fertility gains of these treatments. Exchangeable K, but not Colwell P, in the soil was significantly increased by residue incorporation. The clayey Vertosol conserved higher levels of nutrients than the sandy Chromosol. Yields under organic SMS can match that of conventional SMS. Residue incorporation in soil improved soil nutrients and reduced weed biomass. [Yadunath Bajgaia, Paul Kristiansena, Nilantha Hulugallea & Melinda McHenrya (2013). Comparison of organic and conventional managements on yields, nutrients and weeds in a corn–cabbage rotation. Renewable Agriculture and Food Systems, online 12 August.] Comment

Canadian environmental groups sue over Ottawa failure to control herbicides banned in Europe

Zheljana Peric / WeedsNews4627 / September 4, 2013 / 9:25:08 PM EST / 0 Comments
[ctvnews.ca 27 Aug 2013] — The Canadian government is facing a series of lawsuits over its refusal to review three pesticides banned in Europe, as well as its delays in deciding what to do about other chemicals that those countries consider too hazardous to use. "(Environmental groups) have made numerous efforts over the past 10 months to have the government comply with its legal duty to subject these pesticides to special reviews," said Lara Tessaro of Ecojustice, which is representing the David Suzuki Foundation and Equiterre. "The government has now outright refused to do that for three pesticides and is delaying its decision for 26 more." The chemicals include chlorthal-dimethyl, a possible carcinogen and herbicide most commonly used on weeds in vegetable operations; trifluralin, a popular herbicide on the Prairies that's highly toxic to fish; and trichlorfon, an insecticide approved for woodlots, Christmas tree plantations and cattle that has been linked to human nerve damage. The chemicals are found in about 700 commercially available products, said Elaine MacDonald, an Ecojustice scientist. All three have been banned in Europe for at least six years. "There's no exaggeration to say these are risky, dangerous chemicals," MacDonald said. The lawsuits argue that under federal legislation, Health Canada is obliged to review any pesticide banned by any country belonging to the Organization for Economic Co-operation and Development. [Photo credit: The Tordon Players] Comment

Commonly used ultraviolet water disinfection treatment increases toxicity of herbicide degradation products

Zheljana Peric / WeedsNews4620 / September 4, 2013 / 8:07:27 PM EST / 0 Comments
Abstract: The widespread occurrence of chlorinated herbicides and their degradation products in the aquatic environment raises health and environmental concerns. As a consequence pesticides, and to a lesser degree their degradation products, are monitored by authorities both in surface waters and drinking waters. In this study the formation of degradation products from ultraviolet (UV) treatment of the three chloroacetamide herbicides acetochlor, alachlor and metolachlor and their biological effects were investigated. UV treatment is mainly used for disinfection in water and wastewater treatments. First, the chemical structures of the main UV-degradation products were identified using gas chromatography coupled with mass spectrometry and liquid chromatography–mass spectrometry. The main transformation reactions were dechlorination, mono- and multi-hydroxylation and cyclizations. The ecotoxicity of the mixed photoproducts formed by UV-treatment until 90% of the original pesticide was converted was compared to the toxicity of chloroacetamides using the green alga Pseudokirchneriella subcapitata, the crustacean Daphnia magna and the marine bacteria Vibrio fischeri as test organisms. UV-treatment of alachlor and metolachlor increased the toxicity compared to the parent compounds while an equal toxicity was found for photolysis products of acetochlor. This suggests that toxic photodegradation products are generated from chloroacetamides under UV-treatment. An important perspective of this finding is that the photolysis products are at least as toxic as the parent compounds.[Yasmine Souissi, Stéphane Bouchonnet, Sophie Bourcier, Kresten Ole Kusk, Michel Sablier, Henrik Rasmus Andersen (2013). Identification and ecotoxicity of degradation products of chloroacetamide herbicides from UV-treatment of water. Science of The Total Environment, Volumes 458–460, 527-534] Comment

Mulching with large round bales between covered beds using an offset round-bale unroller for weed control

Zheljana Peric / WeedsNews4618 / September 4, 2013 / 7:33:25 PM EST / 0 Comments
Abstract: Mulching between rows of plastic used for vegetable production can be an effective practice for controlling weeds. An existing round-bale unroller was modified to create an offset bale unroller, allowing round bales of hay to be unrolled between planting rows with a tractor. This modification has made the practice of mulching with round bales of hay or wheat straw more efficient. This offset round-bale unroller was used to apply hay and wheat straw mulch to between-row areas of ‘Crimson Sweet’ watermelon (Citrullus lanatus) in 2009 and 2010. Hay and wheat (Triticumsp.) straw mulches were applied at two thicknesses, corresponding one and two layers of mulch from the round bale, respectively. All of the hay and wheat straw mulch treatments controlled weeds significantly better than the non-treated controls in both years. There was a significant mulch-type by year interaction for weed control, with 1-year-old hay having less weed control in 2010 compared with 2009, whereas other mulches had improved weed control in 2010. One-year-old wheat straw and new hay had the lowest levels of weed biomass present compared with new wheat straw and the no-mulch control. Mulch thickness significantly affected weed control, with mulches applied in two layers having significantly less weed biomass than those applied in one layer. Weed pressure was significantly less in 2010 compared with 2009. The offset bail-unroller that has been developed to apply mulches to between-row areas of plastic-covered beds is a useful tool that can be used to efficiently unroll round bales of a variety of organic mulches for weed control. [John Wilhoit & Timothy Coolong (2013). Mulching with Large Round Bales between Plastic-covered Beds Using a Newly Developed Offset Round-bale Unroller for Weed Control. HortTechnology, 23(4), 511-516] Comment

Herbicide runoff a threat to Great Barrier Reef water quality

Zheljana Peric / WeedsNews4610 / September 3, 2013 / 9:34:47 PM EST / 0 Comments
[Ecos 26 August 2013] — A 2013 Scientific Consensus Statement on ‘Land use impacts on Great Barrier Reef water quality and ecosystem condition’ has found that the health of key Great Barrier Reef ecosystems is deteriorating due to ‘continuing poor water quality, cumulative impacts of climate change and increasing intensity of extreme events. Mean-annual modelled loads of photosystem II inhibiting herbicides, namely ametryn, atrazine, diuron, hexazinone, tebuthiuron and simazine, are estimated to range between 16,000 and 17,000 kilograms per year. The total pesticide load to the Great Barrier Reef lagoon is likely to be considerably larger, given that another 28 pesticides have been detected in the rivers. The Statement was developed by an independent group of scientists, with oversight from a Reef Plan science panel. The group of scientists – including some from CSIRO’s Water for a Healthy Country and Sustainable Agriculture Flagships – reviewed and synthesised recent scientific findings on water quality in the Great Barrier Reef to reach a consensus on current understanding. They found that ‘the main source of excess nutrients, fine sediments and pesticides from Great Barrier Reef catchments is diffuse source pollution from agriculture’. Comment

Study finds pesticides in "bee-friendly" plants

Zheljana Peric / WeedsNews4601 / August 22, 2013 / 11:03:28 PM EST / 0 Comments
Plants marketed as "bee-friendly" by many home and garden stores may actually contain neonicotinoid pesticides, according to a study released today by USA's Friends of the Earth (FOE). FOE commissioned PhD scientists at the Pesticide Research Institute to examine a sampling of garden plants purchased at top retailers in Washington DC, the San Francisco Bay Area and Minneapolis. The plants were being sold as "bee-friendly," suggesting an absence of chemical treatments that could pose risk to bees. However, when tested, scientists found that seven of the 13 plants contained neonicotinoid pesticides at doses that could harm or kill bees. Some plants contained low levels of neonicotinoids, but two of the plants contained high enough levels to kill bees directly. An additional three plants had high enough levels to cause "serious harm." Sublethal exposure to neonicotinoids, even at low levels, weakens bees and is known to make them disoriented, impairing their ability to navigate to food sources and return to their hives. This effect generally results in bee mortality, and has long been implicated as a primary contributor to Colony Collapse Disorder (CCD). FOE is urging consumers to confront major retailers such as Lowes and Home Depot and demand that they immediately stop sales of lawn and garden plants that have been pretreated with neonicotinoid pesticides. Visit their website, www.foe.org/beeaction, for more information on this effort. Read the Full Report Comment

Getting sheepish on invasive plants

Zheljana Peric / WeedsNews4599 / August 22, 2013 / 9:21:06 PM EST / 0 Comments
[hmbreview.com 15 August 2013 by Stacy Trevenon] -- Land trust employs sheep and goats instead of machines to clear plants. A herd of more than 400 goats and sheep are herded around the corner at Poplar Street and Railroad Avenue toward a nearby pen for grazing on Friday. It’s part of Coastside Land Trust’s habitat restoration project in the area. Rustling sounds of big animals moving through dry brush and a steady stream of 450 fleecy white animals pouring through open lands near the old Ocean Shore Railroad depot are unusual sights and sounds on the coast. But they have greeted residents at Poplar Street and Railroad Avenue for several days. “This is the biggest thing that ever happened around here,” said Betsy Hutchinson of Frenchmans Creek. She often walks her dog by the depot. Throwing back to days when animals, not machines, were key in land management, the animals were trucked to the area for ongoing habitat restoration under the auspices of the Coastside Land Trust. The restoration herd of 450 Dorper/St. Croix cross sheep and Boer goats (the breed has roots in Africa,) were brought in from the Belmont-based Star Creek Land Stewards. The company takes herds to similar jobs around the greater Bay Area. In the wintertime, the herds are based in Los Banos. The herd included two long-bearded billies (male goats) and two rams (male sheep,) but most of the animals were females and pregnant, due to give birth around November. In a projected five-day process and under the watchful eye of Peruvian-born herder Roony Tacza Rojas and his two border collie helpers, the sheep and goats filtered through the land near the depot, devouring invasive plants. On Friday the herd was moved from the county land fill near the Poplar State Beach parking area to the railroad right-of-way. The land is owned by the city of Half Moon Bay, but a conservation easement is held by the land trust, which helps with management of the property. Until their projected departure today or Thursday, the herd will chomp down overgrown invasive plants between Poplar Street and Valdez Avenue, on the railroad right-of-way easement. Comment

Differences in competitive ability between plants from nonnative and native populations of a tropical invader relates to adaptive responses in abiotic and biotic environments

Zheljana Peric / WeedsNews4598 / August 22, 2013 / 9:07:00 PM EST / 0 Comments
Abstract: The evolution of competitive ability of invasive plant species is generally studied in the context of adaptive responses to novel biotic environments (enemy release) in introduced ranges. However, invasive plants may also respond to novel abiotic environments. Here we studied differences in competitive ability between Chromolaena odorata plants of populations from nonnative versus native ranges, considering biogeographical differences in both biotic and abiotic environments. An intraspecific competition experiment was conducted at two nutrient levels in a common garden. In both low and high nutrient treatments, C. odorata plants from nonnative ranges showed consistently lower root to shoot ratios than did plants from native ranges grown in both monoculture and competition. In the low nutrient treatment, C. odorata plants from nonnative ranges showed significantly lower competitive ability (competition-driven decreases in plant height and biomass were more), which was associated with their lower root to shoot ratios and higher total leaf phenolic content (defense trait). In the high nutrient treatment, C. odorata plants from nonnative ranges showed lower leaf toughness and cellulosic contents (defense traits) but similar competitive ability compared with plants from native ranges, which was also associated with their lower root to shoot ratios. Our results indicate that genetically based shifts in biomass allocation (responses to abiotic environments) also influence competitive abilities of invasive plants, and provide a first potential mechanism for the interaction between range and environment (environment-dependent difference between ranges). [Liao Z-Y, Zhang R, Barclay GF, Feng Y-L (2013) Differences in Competitive Ability between Plants from Nonnative and Native Populations of a Tropical Invader Relates to Adaptive Responses in Abiotic and Biotic Environments. PLoS ONE 8(8): e71767] Comment

Effect of aqueous leaf extract of Parthenium hysterophorus L. on the germination and shoot growth of two native species

Zheljana Peric / WeedsNews4595 / August 22, 2013 / 8:55:24 PM EST / 0 Comments
Abstract: In order to evaluate the allelopathic potential of an exotic invasive weed, Parthenium hysterophorus L., the effect of different concentrations of aqueous extracts (5%, 25%, 50%, 75% and 100%) prepared from leaves of P. hysterophorus were studied on the seed germination and seedling shoot growth of two common native herbs, Plantago asiatica L. and Youngia japonica (L.) DC., through laboratory bioassays. The aqueous leaf extracts at the concentrations of 25%, 75% and 100% significantly inhibited the seed germination and seedling shoot growth of two target species. There was complete failure of seed germination of Y. japonica in 75% and 100% aqueous leaf extracts. The inhibitory effect increased with increasing extract concentration. These results suggested that allelopathy may play a role in the impact of P. hysterophorus invasion on native plant recruitment of invaded communities in southern China. [Hu, G., Zhang, Z.H., Hu, B.Q. (2013). Effect of Aqueous Leaf Extract of Parthenium hysterophorus L. on the Germination and Shoot Growth of Two Native Species. Advanced Materials Research, Volumes (726 - 731):4348-4351. DOI10.4028/www.scientific.net/AMR.726-731.4348] Comment

Australia bans 2,4-D HVE

Zheljana Peric / WeedsNews4594 / August 22, 2013 / 8:52:53 PM EST / 0 Comments
[APVMA 21 Aug 2013] -- As part of the ongoing review of 2,4-D, the Australian Pesticides and Veterinary Medicines Authority (APVMA) has cancelled the registration of 11 high volatile ester products (HVE) products and two active constituents. The decision means that the supply of the cancelled 2,4-D HVE active constituent is to cease immediately (21 August 2013). From 31 August 2013 the supply of product containing 2,4-D HVE manufactured up to 21 August 2013 is to cease. People can use products they have already purchased up until 31 August 2014 under the same permit instructions (PER14329) which restricts use to winter only and under strict conditions - use of these products after 31 August 2014 will be illegal. The APVMA suspended registrations and label approvals of 2,4-D products containing high volatile ester forms in 2006. This was on the basis of environmental concerns about off-target damage to nearby crops, vegetation and the environment due to its ability to easily evaporate and be carried long distances under certain conditions. Tight restrictions on the use of 2,4-D HVE products have been in place since 2006 while data about the environmental impact was generated under Australian conditions. The latest assessment of data from the Department of Sustainability, Environment, Water, Population and Communities (DSEWPAC) determined the risks of the use of 2,4-D HVE products under the suspended label instructions are unacceptable and cannot be mitigated. Registrants and approval holders were notified last month of the APVMA's intention to cancel the registration of the products and the active constituents used in the products. The DSEWPAC report was also published on the APVMA website in July. This action completes the review for the high volatile ester forms of 2,4-D. 2,4-D is a herbicide used to control weeds in crops, commercial and industrial areas, turf, forestry and waterways. There are now 220 registered 2,4-D products in Australia, with sales representing about 7–8% of all herbicide sales. Comment

Planting pattern and weed management for enhancing productivity and profitability in urdbean + finger millet intercropping

Zheljana Peric / WeedsNews4592 / August 22, 2013 / 8:30:43 PM EST / 0 Comments
Abstract: An experiment was conducted during Kharif 2009 and 2010 to find out the most appropriate planting pattern and weed management practice for obtaining higher yield in urdbean + finger millet intercropping in replacement series. Results revealed that urdbean + finger millet (1:1 or 2:1) recorded significantly lower weed dry matter and higher weed control efficiency over the sole urdbean or finger millet. However, intercropping of urdbean + finger millet (1:1) being at par with 2:1 and finger millet sole, yielded higher urdbean equivalent over sole urdbean. One hand weeding 25 DAS recorded the highest weed control efficiency and urdbean equivalent yield with higher number of ear heads/plant and fingers/ear head in finger millet over other weed management practices. [Chandra, B. & Singh, V.K. (2013). Planting pattern and weed management for enhancing productivity and profitability in urdbean + finger millet intercropping. Journal of Food Legumes. Vol 26(1& 2):112-115] Comment

Goats replace herbicides at historic Washington, DC landmark

Zheljana Peric / WeedsNews4583 / August 11, 2013 / 8:58:33 PM EST / 0 Comments
[Beyond Pesticides, August 8, 2013] — Over 100 goats have been tasked with controlling poison ivy, ground cover, vines and other invasive weeds at the Congressional Cemetery this week. The Association for the Preservation of The Historic Congressional Cemetery partnered with Eco-Goats to control the invasive species that threaten large mature trees, which can fall and damage headstones. In addition to their weed-managing services, the goats provide free fertilizer, aerate the soil with their hooves, and eliminate the need for chemicals. The goats, penned outside of the burial area of nearly 200 members of Congress, J. Edgar Hoover and other notable Washingtonians, will graze 24 hours a day for the next several days to control weeds along the perimeter of the cemetery. At a press event held Wednesday at the cemetery, Paul Williams, president of the Association explained that the goats are being used as an eco-friendly and cost-efficient alternative to machines or pesticide, considering the cemetery rests on the banks of the Anacostia River. (See information on pesticides and waterways.) Brian Knox, president of President of Sustainable Resource Management, Inc. and the supervising forester for Eco-Goats explained that goats act as broad-spectrum weed killers; they will eat everything. In fact, goats are often more efficient at eradicating weeds, and are more environmentally sustainable than using harmful pesticides and chemicals. Once goats graze a weed it cannot go to seed because it has no flower and cannot photosynthesize to take in sunlight and build a root system because it has no leaves. Grasses are a last choice for goats, which means the desirable grass species are left behind with natural fertilizer to repopulate the land. Goats are notorious for eating poisonous plants, such as poison ivy and poison oak, and can handle them without getting sick.Though this is the first time goats will be used in Washington, D.C. to control weeds, goat grazing is a growing movement throughout the nation. Communities across the nation, from California to Colorado toChicago, have discovered that grazing goats is a great option for land that suffers from unwanted plants, low organic matter and soil compaction. [Photos by Beyond Pesticide] Comment

Glyphosate applications on invasive plants voted down in Clay Township, Michigan USA

Zheljana Peric / WeedsNews4579 / August 11, 2013 / 7:53:43 PM EST / 0 Comments
[The Voice 09 Aug 2013 by Jeri Packer] — A group of Clay Township (Michigan, USA) residents let their concerns over a broad-spectrum weed killer be known last week, which led to the township board voting down a scheduled aquatic herbicide application. The spray of concern was glyphosate. Glyphosate has been the subject of rigorous debate because of its toxic properties, especially by Clay Township residents along the Colony Drive/Aqua Isles canals and the "bird canals" of Flamingo, Cardinal, Bluebill and Audubon. The municipality provides two advertised public hearings, where citizens get to speak their minds on the subject and then the township board votes. In this case, the objections were so strong, the board voted after the first hearing to cancel any chemical treatment for weeds. "They were overwhelming against it," Clay Township Supervisor Artie Bryson said. "We chose not to proceed with another hearing." Bea Zrepskey, secretary to the Colony Park Association Board, was adamantly opposed to the treatments. "Children swim in these canals," she said. "People water their lawns and gardens with water pumped from the canal. Water can collect in puddles from sprinkling the lawn and pets and other wildlife can drink the treated water." In her extensive research, she said she has found that herbicides are cumulative in the human body. In most cases, she said, it is a long time later before cancer and other diseases occur from the accumulation of chemicals and heavy metals. Even though the special assessment was turned down, she worries about the individual homeowners who freely use the chemical to treat their landscapes. "People are doing the same thing privately with no real knowledge of the danger," she said. "People use Preen, a long-lasting weed preventive herbicide, on their garden beds which then washes into our waterway." According to Zrepskey's research, when herbicides kill aquatic plants, they lie in a "septic mass" at the bottom of the canal, robbing oxygen from the water and causing pollution. Sarah Kilchevskyi lives on Cardinal Street, in the special assessment area. She figured, for her single lot, the estimated amount of her assessment would be about $142 over five years. "It's definitely not about the money," she said. "It's about putting a chemical into the water we swim in, use for gardens and our pets that we do not really need. As far as I understand, we are not battling an invasive species – they're just naturally occurring weeds." Kilchevskyi said when she was young, her dad and neighbors used to pull the plants up with rakes or boat motors, "at no sacrifice to the health of our families or little ones." [Photo: Child swimming in the area proposed to be polluted with herbicides: Harsens Island, MI gallery] Comment

Making money with weeds

Zheljana Peric / WeedsNews4577 / August 10, 2013 / 10:07:55 PM EST / 0 Comments
Abstract: The need for the adoption of innovation in weed management seems obvious in agriculture where significant economic issues arise in relation to 'problem' weeds. When a farmer has a problem with weeds, who is he or she going to ask for help? Most weed experts I know assume that the needs of the farmer are related to the weed species and refer them to information about the weed and which chemicals can be used to kill it. The farmer, however, is running a business and his or her needs are related to the profitability and sustainability of the enterprise as a whole. The farmer has questions that relate to how to make money from managing the farm as a whole. Information on how to kill a weed with herbicide may have little relevance to making money in this context, indeed, such advice might make the situation worse for the farmer, both from an economic and an environmental point of view. By only considering a list of chemicals supplied by an agricultural adviser, the farmer will only be getting advice that maximises profit for the chemical supplier. Such advice may not be the kind of advice that maximises profitability for the farmer, especially in the long-term. For example, if the advice is to knock down or 'terminate' a weedy cover crop with herbicide instead of using the cover crop for fodder, the chemical supplier will profit and the farmer will miss out on an important economic opportunity. [Photo: Holisically managed cattle at Eggers Farm , USA]

Under a chemically based weed control strategy, problem weeds may develop chemical resistance, requiring more chemicals of higher toxicity. In this scenario -- a very common one these days I should add -- the agricultural chemical supplier is selling a solution to fix the problem they have created. The farmer is losing by being locked into an expensive chemical dependency and missing out on profitable options, such as using the weed biomass to feed stock or replenish the soil.

As the above is intended to illustrate, in weed management, the assumption is often that it is the weed that is having the financial impact rather than the context in which the weed issue arises and is then managed. Thus, and as Allan Savory would be quick to point out, farmers should not necessarily be interested in killing weeds, but rather, they should be turning their attention to finding out what they are doing to cause weeds to florish and how they can change this context so that their land management generates income and makes more profit. By only addressing the eradication of a weed, a farmer is failing to recognise that he or she is only seeing the symptom of a system out of balance – their farm ecosystem – and that by thinking about weeds from within a more holistic context, they can maximise the profitability of their enterprise. Holistic or systems thinking is needed to ‘make money out of weeds’. [Low, D. W. (2013). Making money with weeds. Presented at The Day After Tomorrow Conference, Orange, Australia, 6th August - Download PowerPoint 19.5MB] Comment

Savory Institute Conference: scaling up holistic management around the world

Zheljana Peric / WeedsNews4574 / July 30, 2013 / 9:44:38 PM EST / 0 Comments
[foodtank.org 19 July 2013 by Judith D. Schwartz] — Last month Holistic Management—the land stewardship model in which livestock serve as tools for restoration, developed by wildlife biologist Allan Savory—became a global movement. The first Savory Institute International Conference, held at the end of June in Boulder, Colorado, brought together ranchers, scientists, investors, and environmental activists from more than ten nations to grapple with how to scale up Holistic Management around the world. In his opening remarks, Savory called agriculture a “destructive” force that “produces far more eroding soil than food”. However, he stressed that we already know how to shift to regenerative means of food and fiber production in a way that improves land and returns carbon and water to the soil, the lack of which inevitably leads to desertification. As he did in his TED talk, he said that reviving the world’s grasslands—which, he noted, has been proven can be done with Holistic Planned Grazing—is the key to meeting the formidable challenges of climate change, biodiversity loss, and the multiple social and political crises that ensue when land no longer sustains life. [Photo: Raising cattle using Holistic Management is an effective method for preventing & controlling weeds without the use of chemicals.] Comment

Herbicide exposure linked to depression among agricultural workers in France

Zheljana Peric / WeedsNews4571 / July 28, 2013 / 7:20:23 PM EST / 0 Comments
Abstract: Pesticides are ubiquitous neurotoxicants, and several lines of evidence suggest that exposure may be associated with depression. Epidemiologic evidence has focused largely on organophosphate exposures, while research on other pesticides is limited. We collected detailed pesticide use history from farmers recruited in 1998–2000 in France. Among 567 farmers aged 37–78 years, 83 (14.6%) self-reported treatment or hospitalization for depression. On the basis of the reported age at the first such instance, we used adjusted Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals for depression (first treatment or hospitalization) by exposure to different pesticides. The hazard ratio for depression among those who used herbicides was 1.93 (95% confidence interval (CI): 0.95, 3.91); there was no association with insecticides or fungicides. Compared with nonusers, those who used herbicides for <19 years and ≥19 years (median for all herbicide users, 19 years) had hazard ratios of 1.51 (95% CI: 0.62, 3.67) and 2.31 (95% CI: 1.05, 5.10), respectively. Similar results were found for total hours of use. Results were stronger when adjusted for insecticides and fungicides. There is widespread use of herbicides by the general public, although likely at lower levels than in agriculture. Thus, determining whether similar associations are seen at lower levels of exposure should be explored.[Marc G. Weisskopf*, Frédéric Moisan, Christophe Tzourio, Paul J. Rathouz & Alexis Elbaz (2013). Pesticide exposure and depression among agricultural workers in France. American Journal of Epidemiology, online 12 July 2013.] [Photo credit: getfarming.com.au] Comment

Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

Zheljana Peric / WeedsNews4569 / July 27, 2013 / 10:00:46 PM EST / 0 Comments
Abstract: Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment. [Smalling, K. L., Fellers, G. M., Kleeman, P. M. and Kuivila, K. M. (2013). Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA. Environmental Toxicology and Chemistry, 32: 2026–2034. doi: 10.1002/etc.2308] Comment

"We were told it was safe enough to drink" - ABC report on dangerous herbicides

Zheljana Peric / WeedsNews4562 / July 25, 2013 / 9:55:13 PM EST / 0 Comments
[ABC 22 July 2013] -- In the 1980s and 1990s governments across Australia outlawed the use of the herbicide 245T. The ban was introduced for one very good reason - 245T contains dioxin, a chemical impurity with the potential to seriously harm people who are exposed to it. But has the dioxin menace been tamed? Four Corners reveals evidence that this potentially deadly chemical compound may still be present in weed control products and that authorities do not routinely test for it. The program also reveals that this hands-off approach to regulation is entirely in keeping with the way governments have dealt with the lethal chemical dioxin over four decades. In the 1960s and 70s the solution used in weed eradication often involved the spraying of herbicides 245T and 24D. Both substances contained dioxin. It was common practice for workers, in many parts of the country, to decant the herbicides from large drums into backpacks to apply the chemicals. In many cases they sprayed the liquid without using proper protective clothing.

Four Corners reveals the full extent of the problems caused by the chemicals. We meet the families of former government employees who have died almost certainly as a result of their exposure. The program also reveals the failure of successive governments to acknowledge the problems associated with the use of the chemicals and the refusal of those governments to pay adequate compensation to people who sprayed them and who have suffered massive health problems as a result. Four Corners reveals there are now reports of the children and partners of former sprayers also getting sick.

It is now widely accepted by experts that dioxin is the common factor that causes health problems in people who were exposed to herbicides. Although governments finally banned 245T, they continued to sanction the use of 24D as a herbicide, provided it did not contain anything more than trace levels of dioxin. The problem is authorities admit they do not routinely test for the potentially lethal chemical contaminant.

Four Corners has found evidence that herbicides containing 24D, currently being sold, do have levels of dioxin which could pose a potential health risk. Significantly, experts warn that cheap imports might be a source of herbicides contaminated with dioxin and yet those imports haven't attracted significant scrutiny.

To add to the problem posed by the lack of regulation enforcement, there is also evidence that farmers are spraying forms of 24D that drift across large tracts of neighbouring land creating a potential danger to other farm crops. Comment

Chemical Time Bomb, reported by Janine Cohen and presented by Kerry O'Brien, went to air on Monday 22nd July at 8.30pmon ABC1. The program is repeated on Tuesday 23rd July at 11.35pm. To view online, click here.

Canada's' City of Victoria Pesticide Reduction Bylaw

Zheljana Peric / WeedsNews4557 / July 25, 2013 / 9:47:42 PM EST / 0 Comments
[TWN 25 July 2013] -- In February 2008, the City of Victoria, Canada became the first municipality in the Capital Region to adopt a bylaw to regulate the use of pesticides on residential and public property. Enforcement of the bylaw began January 2009.The Pesticide Use Reduction Bylaw is in place to protect the natural environment by regulating and reducing the non-essential (cosmetic) use of pesticides, specifically on lawns, trees, shrubs, and flowers, to beautify residential and public property. The bylaw still allows pesticides to be used on hard landscaping surfaces such as driveways, sidewalks, curbs, and gutters, as well as on or inside buildings. A pesticide can be long lived. It often spreads from where it is applied and can easily move through the air, land and water to our lakes, streams and ocean. Although an individual lawn or garden may seem quite small, the cumulative effect of pesticide use on many lawns and gardens can have a significant impact on a neighbourhood and our environment.

Dow herbicide that contaminated Green Mountain Compost now effectively banned in the Northeast USA

Zheljana Peric / WeedsNews4556 / July 25, 2013 / 9:45:13 PM EST / 0 Comments
[vtdigger.org 10 June 2013] -- A herbicide that tainted Green Mountain Compost (GMC) last summer can no longer legally be used on Vermont pastures. But compost companies still worry the chemical will find its way into their products. The GMC compost, made at the Chittenden Solid Waste District facility in Williston, damaged or killed some broadleaf garden plants, such as tomatoes, costing the district at least $800,000. The cause of the contamination was found to be aminopyralid. That agent is found in Dow weed-control products Milestone and Forefront and it apparently entered Green Mountain Compost in manure from horses that consumed feed treated with aminopyralid products. Milestone is used to kill up to 85 plant varieties. The discovery was the result of many months of forensic work by CSWD, the state Agency of Agriculture, the Environmental Protection Agency and pesticide giant Dow Agrosciences. The identification of aminopyralid as the cause of the compost contamination led to Dow voluntarily changing its labeling of the chemical, ruling out its use on pastures in New England or for any purpose in New York. Any violation, or off-label use, is a federal offense. The new restrictions are aimed at keeping aminopyralid out of horse feed, specifically hay. Horse manure is often a key ingredient in local compost.

Weeds warrant urgent conservation

Zheljana Peric / WeedsNews4554 / July 24, 2013 / 9:56:14 PM EST / 0 Comments
[Nature 22 July 2013 by Virginia Gewin] — Faced with climate change, plant breeders are increasingly turning to the genomes of the wild, weedy relatives of crops for traits such as drought tolerance and disease resistance. But a global analysis of 455 crop wild relatives has found that 54% are underrepresented in gene bank collections — and that many, including ones at risk of extinction, have never been collected. The findings, released on 22 July by the International Center for Tropical Agriculture (CIAT) in Cali, Colombia, will guide the largest international initiative so far to conserve crop wild relatives. The effort — which is being spearheaded by the Global Crop Diversity Trust, based in Bonn, Germany, in partnership with the Millennium Seed Bank at the Royal Botanic Gardens in Kew, UK — is deemed urgent at a time when one in five plants faces extinction. [Image: In an effort to breed better crops, a global survey has identified geographical regions where the wild relatives of 29 crops are in greatest need of collection if their genetic diversity is to be conserved — with notable hotspots in northern Australia and Portugal.] read more …

Rotterdam bans Monsanto’s RoundUp

Zheljana Peric / WeedsNews4551 / July 24, 2013 / 9:06:27 PM EST / 0 Comments
[occupymonsanto360.org 19 July 2013] — Just a short while ago, on June 27th, the Rotterdam city council voted to ban Monsanto’s controversial Roundup herbicide. The initiative was begun largely thanks to a citizen run petition campaign appropriately named, “Non-toxic Sidewalks for Our Children”, along with a lot of support from the Green Party to get it passed. While glyphosate (RoundUp’s “active” ingredient) has long been believed to be quite non-toxic, recent studies have shown that to be very much untrue. The herbicide, currently the most used in the world by a large margin, has been found to be especially harmful when combined with the adjuvants labeled as “inert ingredients” which are designed to increase delivery of the pesticide to target plants. This ban is considered a big win by the city and a large number of the citizenry who have been working hard to both start the initiative and get it passed. RoundUp has already been found in the urine of a majority of western European urbanites, according to a recent study. “It is bad stuff and I’m glad we’re giving it up,” says Emile Cammeraat, Green party leader in the council. ’The producer Monsanto also provides genetically engineered seeds, Monsanto’s own plants are the only thing RoundUp doesn’t kill ... Roundup is simply unnecessary, as there are organic alternatives." In addition to this win, the Greens have many more reasons to celebrate as they had 12 more of their proposals passed. The city will be designing and building many more projects all over ranging from new parks and play areas, new fruit trees all over, initiatives to help support the bees and other important wildlife, all the way up to new green wall projects being erected. ”Think of more flowers, more space for urban wildlife and (natural) scrublands, and less lawnmowing.”, said Ms. Cammeraat. The initiative was clearly started primarily out of parents’ concern for the children playing in parks and other areas that may be contaminated by the pesticide, but as often is the case with environmentally related initiatives such as these; the benefits it ultimately results in are innumerable. Total cost of the 12 initiatives is projected to be approximately 90,000 euros (the glyphosate ban costs little to nothing at all). [Photo: Rotterdam city worker sprays RoundUp alongside urban walkways .Translated by Fritz Kreiss] Comment

Europe views gmo's with suspicion

Zheljana Peric / WeedsNews4543 / July 21, 2013 / 9:19:35 PM EST / 0 Comments
[ABC News 19 July 2013] — United States agrochemicals giant Monsanto will drop all requests to be allowed to grow new genetically modified foods in the European Union, which has for years held up approval. The company says it would instead focus on its conventional seeds business and enabling imports of such products into the region. "We will no longer be pursuing approvals for cultivation of new biotech crops in Europe," the company said in a statement. The European Commission, the EU's executive arm, said it "took note of the decision" by Monsanto which produces a whole stable of GM crops and associated agrochemicals in wide use in the US and elsewhere. In Europe, however, there is widespread suspicion about the use of GM food products, with many fearing their use could have an unintended long-term impact on health. Environmental groups welcomed Monsanto's announcement. "This is great news for science and research in Europe," Greenpeace EU spokesman Mark Breddy said. "Over the last couple of decades, GM crops have proven themselves to be an ineffective and unpopular technology, with unacceptable risks for our environment and health. "Monsanto's retreat could finally create the space for European farming to focus on modern practices and technologies that offer real advances for food production and rural communities." Comment

Superweeds: How biotech crops bolster the pesticide industry

Zheljana Peric / WeedsNews4537 / July 14, 2013 / 8:30:42 PM EST / 0 Comments
Summary: Genetically engineered (GE) crops were first approved in the United States in the 1990s, and since then the United States has been the biggest global adopter of this technology. GE crops were supposed to improve yields, lower costs for farmers and reduce agriculture’s environmental impact. Yet nearly 20 years after their introduction, genetically engineered crops have not provided the benefits promised by the companies that patented them. Food & Water Watch examined U.S. Department of Agriculture (USDA) and U.S. Environmental Protection Agency (EPA) data to document the increased use of herbicides that has accompanied the adoption of herbicide-tolerant GE crops. Our analysis looks at the rapid proliferation of GE crops and affiliated pesticides in the United States and points out the interdependent relationship between these two industries that also fuels the crisis of weed resistance. Food & Water Watch evaluated data from the International Survey of Herbicide Resistant Weeds that reveal burgeoning herbicide-resistant weeds caused by the over-reliance on glyphosate for broad control of weeds. These data make it clear that the problem of herbicide-resistant weeds will not be solved with the intensified use of older, more toxic herbicides like 2,4-D and dicamba. [Superweeds: How Biotech Crops Bolster the Pesticide Industry. Food & Water Watch]

Scouting for water chestnuts to protect Lake Hopatcong

David Low / WeedsNews4533 / July 13, 2013 / 11:20:52 PM EST / 0 Comments
[Daily Record 06 July 2013] Hopatcong USA — A group of 20 kayakers paddled past the Hopatcong State Park beach, next to kids swimming and people fishing. They were Water Scouts, on the lake to work. The Water Scouts have spent the past month scouring Lake Hopatcong for invasive plant species, particularly the water chestnut. The plants, native to Eurasia and Africa, displace native plants and reproduce rapidly by dropping black seeds bearing four sharp spines to a lake’s sediment. Thick mats of the plant can choke out other native plants that are a vital part of a lake’s ecosystem. The water chestnut was first sighted in New Jersey in 2001 and has been spreading rapidly in many waterways in New Jersey and other states, scientist Chris Mikolajczyk said. It was spotted in a cove of Lake Hopatcong near the Landing shoreline in 2010, and it has become the scourge of the nearby Lake Musconetcong over the past several years. Water Scouts hand pulled the chestnut out of the water in 2010, and it hasn’t returned since, due in large part to the watchful eyes of the Scouts. The Water Scouts, which is made up of mostly adults who live on the lake, was founded with the purpose of keeping unwanted species out of the lake.

Sustainability and innovation in staple crop production in the US Midwest

Zheljana Peric / WeedsNews4532 / July 12, 2013 / 1:02:23 PM EST / 0 Comments
Summary: An agroecosystem is constrained by environmental possibility and social choices, mainly in the form of government policies. To be sustainable, an agroecosystem requires production systems that are resilient to natural stressors such as disease, pests, drought, wind and salinity, and to human constructed stressors such as economic cycles and trade barriers. The world is becoming increasingly reliant on concentrated exporting agroecosystems for staple crops, and vulnerable to national and local decisions that affect resilience of these production systems. We chronicle the history of the United States staple crop agroecosystem of the Midwest region to determine whether sustainability is part of its design, or could be a likely outcome of existing policies particularly on innovation and intellectual property. Relative to other food secure and exporting countries (e.g. Western Europe), the US agroecosystem is not exceptional in yields or conservative on environmental impact. GM crops have maintained or increased US pesticide use relative to equally advanced competitors. The pattern and quantities unique to the use of GM-glyphosate-tolerant crops has been responsible for the selection of glyphosate-tolerant weeds, with estimates of resistant weeds on between 6 and 40 million hectares in the United States (Waltz 2010, Owen 2011, Benbrook 2012, Heap et al. 2013). We suggest strategies for innovation that are responsive to more stakeholders and build resilience into industrialized staple crop production. [Heinemann, J.A., Massaro, M., Coray, D.S., Agapito-Tenfen, S. Z. & Wen, J.D. (2013). Sustainability and innovation in staple crop production in the US Midwest. International Journal of Agricultural Sustainability, DOI:10.1080/14735903.2013.806408].

Imact of pesticide application in Gaza Strip

Zheljana Peric / WeedsNews4529 / July 12, 2013 / 12:31:01 PM EST / 0 Comments
Abstract: This article reviews the application of pesticides in Gaza Strip, Palestine and discusses its associated health risks. This study is based on data collection and analysis. Data showed that large quantities of pesticides are used in Gaza Strip and the quantities are increased annually. Analyzing the data indicates that large numbers of pesticides are used for controlling different types of pests. Some pesticides are restricted by law but are available in the local market. Classification of pesticides according to its biological activity indicates that insecticides are the largest uses among other pesticides. Reviewing the acute poisonous cases in health records indicates that the reported acute toxic cases were among local farmers in Gaza and the number of acute toxic cases increased annually indicating direct health risks associated with pesticide use. In addition, the increased number of congenital malformation among the newborns indicates indirect health risks. Moreover, the number of cancer cases in Khan Younis governorate indicates a positive association with pesticide use. Classification of pesticides according to WHO standards identified extreme toxic pesticides (e.g parathion), highly toxic (dichlorvos), moderately toxic (malathion) and less toxic ones. These Pesticides have a wide range of octanol-water partitioning coefficient (Kow, log P) values (-0.8 - 6.6), which results in a variety of storage and transport patterns in human bodies. They may move from the storage sites (e.g fat bodies) via partitioning to other parts of the human body. A pesticide with high Kow log P value (hydrophobic) such as Fenvalerate can be stored in fat containing particles and be released in milk secretion exposing fetus, mother, and infants to health risks. A satisfactory solution to these problems is the implementation of restriction measures and the performance of frequent pesticide residue analysis of food samples. [El-Nahhal, Y., & Radwan, A.A. (2013). Human health risks: Impact of pesticide application. Journal of Environment and Earth Science, 3(7):199-210].

Comparison of synthetic and organic herbicides applied banded for weed control in carrots

Zheljana Peric / WeedsNews4524 / July 6, 2013 / 9:57:55 PM EST / 0 Comments
Abstract: The necessity to reduce environmental impact and control the increasing cost of production has many carrot growers seeking new methods of crop management. This research evaluated the potential of applying herbicides in 30-cm bands over the carrot row in combination with between-the-row cultivation to control weeds. Linuron applied in a 30-cm-wide band over the row and linuron applied broadcast provided effective weed control and comparable yield. Clove oil and citrus oil gave slightly better weed control and yield than acetic acid and flaming at the late seeding date. This study demonstrates that acceptable weed control with minimal impact on yield can be achieved with the use of synthetic and organic herbicides applied as a 30-cm-wide band over the row combined with between-row cultivation. This method of weed control provides a 66% reduction in herbicide applied per hectare compared with a broadcast application. [Main, D. C., Sanderson, K. R., Fillmore, S. A. E. and Ivany, J. A. (2013). Comparison of synthetic and organic herbicides applied banded for weed control in carrots ( Daucus carota L.). Can. J. Plant Sci., 93. on-line June 27.] Comment

Keywords: Herbicide, carrot, seeding date, banded herbicide, clove oil, citrus oil, acetic acid, organic

Mental models of organic weed management: Comparison of New England US farmer and expert models

Zheljana Peric / WeedsNews4523 / June 28, 2013 / 10:40:50 PM EST / 0 Comments
Abstract: Weeds are a major challenge for organic farmers, yet we know little about the factors influencing organic farmers’ weed management decisions. We hypothesized that farmers and scientist ‘experts’ differ in fundamental areas of knowledge and perceptions regarding weeds and weed management. Moreover, these differences prevent effective communication, outreach programming and research prioritization. An expert mental model, constructed primarily from interviews with research scientists and extension professionals, revealed expert emphasis on knowledge of ecological weed management as crucial for successfully implementing such strategies. We interviewed 23 organic farmers in northern New England, yielding an aggregate farmer mental model to compare with the expert model. Farmers demonstrated knowledge of the major concepts discussed by experts, but differed in emphasis. Farmers placed less emphasis on ecological complexity than experts. One-third of farmers interviewed discussed the potential role of weeds as indicators of soil nutrient status, a concept of which experts were skeptical. Farmer beliefs about the weed seedbank highlighted potential misconceptions regarding seed persistence, with one-fourth of farmers focusing on the concept that seeds can live for an exceptionally long time in the soil, while experts focused on the concept of the seed half-life. Farmers emphasized the role of experience, both their own and that of other farmers, rather than knowledge derived from scientific research. Farmers considered yield and the cost of time and labor as equally at risk because of weeds, whereas experts predominantly discussed yield loss. During discussions of management, both farmers and experts most emphasized risks associated with cultivation and benefits associated with cover cropping. These results have prompted us, first, to develop new educational materials focused on weed seed longevity and management of the weed seedbank, and, second, to conduct regional focus groups with farmers who prioritize fertility management in their efforts to control weeds, especially manipulations of soil calcium and magnesium. [Randa Jabbour, Sarah Zwickle, Eric R. Gallandt, Katherine E. McPhee, Robyn S. Wilson & Doug Doohan (2013). Mental models of organic weed management: Comparison of New England US farmer and expert models. Renewable Agriculture and Food Systems, Online 27th June 2013.]

Weeds Make Their Way from Garden to Gourmet

Zheljana Peric / WeedsNews4516 / June 26, 2013 / 11:14:48 AM EST / 0 Comments
Article by Thomas Szymanski: Weeds, like dandelion, are becoming increasingly popular with reputable chefs and are making their way into farmers' markets and grocery stores alike.Common weeds that gardeners spend time and money combating may soon be finding their way into kitchens. The rise in popularity of incorporating plants commonly thought of as weeds into culinary repertoires is thanks in large part to recent interest in foraging.Noma, a Danish restaurant whose menu is crafted around locally foraged edibles, has solidly held a top spot as one of the world’s best restaurants for the past eight years and boasts two Michelin stars. Integrating herbage such as dandelion and stinging nettle into diets not only fosters biodiversity of gardens, but may also be a way to enrich meals with unique flavors and valuable nutrients. The idea of weeds as food has steadily been creeping into mainstream discussions of sustainability, farming, and nutrition. This past February, weeds made it to the main stage of the TEDxManhattan Changing the Way We Eat event, where corporate attorney-turned-weed forager Tama Matsuoka Wong expounded on the environmental and health benefits of regularly incorporating weeds into one’s diet. In her presentation, "How I Did Less and Ate Better, Thanks to Weeds",Wong claimed that “weeds are the ultimate, opportunistic, sustainable plants.” She places the cultivation of weeds as food in direct opposition to the nutrient-depleting monoculture systems currently dominating agricultural landscapes. Weeds naturally exist among and alongside other species, and with their presence, biodiversity of the growing area is often increased, and the soil subsequently enriched.

Green Highways: New Strategies To Manage Roadsides as Habitat

Zheljana Peric / WeedsNews4509 / June 26, 2013 / 10:49:43 AM EST / 0 Comments
Article by Richard Conniff: From northern Europe to Florida, highway planners are rethinking roadsides as potential habitat for native plants and wildlife. Scientists say this new approach could provide a useful tool in fostering biodiversity. Not long ago, a biologist took Florida landscape architect Jeff Caster aside and suggested that he ought to be designing highway margins not just for safety or scenic value, but as habitat, to help address the nation’s drastic decline in pollinating insects. Caster passed the idea along to his boss at the Florida State Department of Transportation (DOT), who looked at him as if he were crazy. Even in the best of circumstances, highways are notorious for fragmenting habitat, spreading pollution, causing roadkills, and otherwise disrupting the natural world. Highways are where insects go to be splattered on windshields. “You expect the DOT to do research on bees?” she told him. “Get real.” Instead, Caster walked her through the reasoning behind the proposal from University of Florida entomologist Jaret C. Daniels: The population of feral honeybees has dropped more than 50 percent nationwide over the past half-century. Pathogens, pesticides, and habitat loss have also decimated native pollinating insect species. The tripling of herbicide use in agriculture since the introduction of Roundup Ready corn and soybeans has also eliminated milkweed and other native species that used to live in U.S. farm fields. That’s caused monarch butterfly populations to crash, says University of Kansas insect ecologist Orley Taylor, founder of Monarch Watch. Click here for full article.[Photo credit: Jaret Daniels, Wildflowers, Gaillardia pulchella, bloom along a Florida road.]

Relay-intercropped forage legumes help to control weeds in organic grain production

Zheljana Peric / WeedsNews4503 / June 25, 2013 / 9:24:41 PM EST / 0 Comments
Abstract: In organic grain production, weeds are one of the major limiting factors along with crop nitrogen deficiency. Relay intercropping of forage legume cover crops in an established winter cereal crop might be a viable option but is still not well documented, especially under organic conditions. Four species of forage legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) were undersown in six organic wheat fields. The density and aerial dry matter of wheat, relay-intercropped legumes and weeds were monitored during wheat-legume relay intercropping and after wheat harvest until late autumn, before the ploughing of cover crops. Our results showed a large diversity of aerial growth of weeds depending on soil, climate and wheat development. The dynamics of the legume cover crops were highly different between species and cropping periods (during relay intercropping and after wheat harvest). For instance, T. repens was two times less developed than the other species during relay intercropping while obtaining the highest aerial dry matter in late autumn. During the relay intercropping period, forage legume cover crops were only efficient in controlling weed density in comparison with wheat sole crop. The control of the aerial dry matter of weeds at the end of the relay intercropping period was better explained considering both legumes and wheat biomasses instead of legumes alone. In late autumn, 24 weeks after wheat harvest, weed biomass was largely reduced by the cover crops. Weed density and biomass reductions were correlated with cover crop biomass at wheat harvest and in late autumn. The presence of a cover crop also exhibited another positive effect by decreasing the density of spring-germinating annual weeds during the relay intercropping period. [Camille Amossé, C., Marie-Hélène Jeuffroy, M-H., Celette, F. & David, C. (2013). Relay-intercropped forage legumes help to control weeds in organic grain production. European Journal of Agronomy, 49:158–167. http://dx.doi.org/10.1016/j.eja.2013.04.002]

Unravelling the beneficial role of microbial contributors in reducing the allelopathic effects of weeds

Zheljana Peric / WeedsNews4500 / June 25, 2013 / 1:50:38 PM EST / 0 Comments
Abstract: The field of allelopathy is one of the most fascinating but controversial processes in plant ecology that offers an exciting, interdisciplinary, complex, and challenging study. In spite of the established role of soil microbes in plant health, their role has also been consolidated in studies of allelopathy. Moreover, allelopathy can be better understood by incorporating soil microbial ecology that determines the relevance of allelopathy phenomenon. Therefore, while discussing the role of allelochemicals in plant–plant interactions, the dynamic nature of soil microbes should not be overlooked. The occurrence and toxicity of allelochemicals in soil depend on various factors, but the type of microflora in the surroundings plays a crucial role because it can interfere with its allelopathic nature. Such microbes could be of prime importance for biological control management of weeds reducing the cost and ill effects of chemical herbicides. Among microbes, our main focus is on bacteria—as they are dominant among other microbes and are being used for enhancing crop production for decades—and fungi. Hence, to refer to both bacteria and fungi, we have used the term microbes. This review discusses the beneficial role of microbes in reducing the allelopathic effects of weeds. The review is mainly focused on various functions of bacteria in (1) reducing allelopathic inhibition caused by weeds to reduce crop yield loss, (2) building inherent defense capacity in plants against allelopathic weed, and (3) deciphering beneficial rhizospheric process such as chemotaxis/biofilm, degradation of toxic allelochemicals, and induced gene expression. [Mishra, S., Upadhyay, R.S. & Chandra Shekhar Nautiyal, C.S. (2013). Unravelling the beneficial role of microbial contributors in reducing the allelopathic effects of weeds. Applied Microbiology and Biotechnology. 97(13):5659-5668]

Meta-analysis: Bug and weed killers, solvents may increase risk of Parkinson's disease

Zheljana Peric / WeedsNews4498 / June 25, 2013 / 1:34:18 PM EST / 0 Comments
Press Release: MINNEAPOLIS – A large analysis of more than 100 studies from around the world shows that exposure to pesticides, or bug and weed killers, and solvents is likely associated with a higher risk of developing Parkinson’s disease. The research appears in the May 28, 2013, print issue of Neurology®, the medical journal of the American Academy of Neurology. “Due to this association, there was also a link between farming or country living and developing Parkinson’s in some of the studies,” said study author Emanuele Cereda, MD, PhD, with the IRCCS University Hospital San Matteo Foundation in Pavia, Italy. The research was also conducted by Gianni Pezzoli, MD, with the Parkinson Institute – ICP, Milan. For the analysis, researchers reviewed 104 studies that looked at exposure to weed, fungus, rodent or bug killers, and solvents and the risk of developing Parkinson’s disease. Studies that evaluated the proximity of exposure, such as country living, work occupation and well water drinking were also included. The research found that exposure to bug or weed killers and solvents increased the risk of developing Parkinson’s disease by 33 to 80 percent. In controlled studies, exposure to the weed killer paraquat or the fungicides maneb and mancozeb was associated with two times the risk of developing the disease. “We didn’t study whether the type of exposure, such as whether the compound was inhaled or absorbed through the skin and the method of application, such as spraying or mixing, affected Parkinson’s risk,” said Cereda. “However, our study suggests that the risk increases in a dose response manner as the length of exposure to these chemicals increases.” The study was supported by the Grigioni Foundation for Parkinson's Disease and the IRCCS University Hospital San Matteo Foundation. [(2013). American Academy of Neurology.]

The importance of roads, nutrients, and climate for invasive plant establishment in riparian areas in the northwestern United States

Zheljana Peric / WeedsNews4488 / June 20, 2013 / 11:34:06 AM EST / 0 Comments
Abstract: Natural and anthropogenic site characteristics play a role in determining the current distribution of invasive plant species. An understanding of these characteristics can be used to prioritize areas for monitoring and control efforts and to determine appropriate management actions to lower site invasion risk. We used species distribution models to look for attributes associated with invasion and to determine the extent to which these attributes varied across a suite of species. We modeled the presence-absence of 11 invasive plant species along riparian areas in the northwestern United States using the model Random Forests. We found that climate variables were most important for predicting species distributions across the large study area and factors related to nutrients, land cover, and disturbance had moderate importance. We also found that there was a general pattern related to invasion for almost all species. Invasion was more likely to occur at hotter, drier sites near roads in unforested areas. In addition, high nutrient levels and proximity to streams with lower baseflow values also generally increased the likelihood that at least one invasive species would be present. Examining patterns across a broad range of regions can help suggest general mechanisms of invasion as well as provide region-specific management recommendations. [ Menuz, D.R. & Kettenring, K. R. (2013). The importance of roads, nutrients, and climate for invasive plant establishment in riparian areas in the northwestern United States. Biological Invasions, 15 (7):1601-1612] Comment

A review of the effects of crop agronomy on the management of Alopecurus myosuroides

Zheljana Peric / WeedsNews4486 / June 14, 2013 / 7:59:41 PM EST / 0 Comments
Abstract: Alopecurus myosuroides is the most important herbicide-resistant weed in Europe, occurring in at least 10 countries (Moss et al., 2007). This study reviews 52 field experiments, mostly from the UK, studying the effects of cultivation techniques, sowing date, crop density and cultivar choice on Alopecurus myosuroides infestations in cereal crops. Where possible, a statistical meta-analysis has been used to calculate average responses to the various cultural practices and to estimate their variability. In 25 experiments, mouldboard ploughing prior to sowing winter cereals reduced A. myosuroides populations by an average of 69%, compared with non-inversion tillage. Delaying drilling from September to the end of October decreased weed plant densities by approximately 50%. Sowing wheat in spring achieved an 88% reduction in A. myosuroides plant densities compared with autumn sowing. Increasing winter wheat crop density above 100 plants m−2 had no effect on weed plant numbers, but reduced the number of heads m−2 by 15% for every additional increase in 100 crop plants, up to the highest density tested (350 wheat plants m−2). Choosing more competitive cultivars could decrease A. myosuroidesheads m−2 by 22%. With all cultural practices, outcomes were highly variable and effects inconsistent. Farmers are more likely to adopt cultural measures and so reduce their reliance on herbicides, if there were better predictions of likely outcomes at the individual field level. [Lutman PJW, Moss SR, Cook S & Welham SJ (2013). A review of the effects of crop agronomy on the management of Alopecurus myosuroides. Weed Research, online 03 June 2013.] Comment

Road verges and winter wheat fields as resources for wild bees in agricultural landscapes

Zheljana Peric / WeedsNews4483 / June 10, 2013 / 8:27:02 PM EST / 0 Comments
Abstract:The effects of farming system on plant density and flowering of dicotyledonous herbs of high value for bees were investigated in 14 organic and 14 conventional winter wheat fields and adjacent road verges. The organic and conventional winter wheat fields/road verges were paired based on the percentage of semi-natural habitats in the surrounding landscape at 1-km scale. Mean density of high value bee plants per Raunkiaer circle was significantly higher in organic winter wheat fields and their adjacent road verges than in their conventionally farmed counterparts. The effect of organic farming was even more pronounced on the flowering stage of high value bee plants, with 10-fold higher mean density of flowering plants in organic fields than in conventional fields and 1.9-fold higher in road verges bordering organic fields than in those bordering conventional fields. In summary, organic farming had a strong positive effect in both road verges and wheat fields on the density of high value bee plants. This was due to the absence of herbicides and to practices inherent to organic farming systems, such as the use of clover (a high value bee plant) as a green manure and fodder crop. [Henriksen, C. I. & Langer, V. (2013). Road verges and winter wheat fields as resources for wild bees in agricultural landscapes. Agriculture, Ecosystems & Environment, 173 (1):66–71] Comment

Ecosystem services of Phragmites in North America with emphasis on habitat functions

Zheljana Peric / WeedsNews4481 / June 5, 2013 / 11:25:44 PM EST / 0 Comments
Abstract: Phragmites australis (common reed) is widespread in North America, with native and nonnative haplotypes. Many ecologists and wetland managers have considered P. australis a weed with little value to the native biota or human society. I document important ecosystem services of Phragmites including support for many common and rare species of plants and animals. This paper is based on an extensive review of the ecology and natural history literature, discussions with field workers, and observations in 13 U.S. states and one Canadian province during the past 40 years. Phragmites sequesters nutrients, heavy metals, and carbon, builds and stabilizes soils, and creates self-maintaining vegetation in urban and industrial areas where many plants do not thrive. These non-habitat ecosystem services are proportional to biomass and productivity. Phragmites was widely used by Native Americans for many purposes; the most important current direct use is for treatment of wastes. Most knowledge of non-habitat ecosystem services is based on studies of Phragmites australis haplotype M (an Old World haplotype). Phragmites also has habitat functions for many organisms. These functions depend on characteristics of the landscape, habitat, Phragmites stand, species using Phragmites, and life history element. The functions that Phragmites provides for many species are optimal at lower levels of Phragmites biomass and extent of stands. Old World Phragmites, contrary to many published statements, as well as North American native Phragmites, provide valuable ecosystem services including products for human use andhabitat functions for other organisms. Phragmites stands may need management (e.g., thinning, fragmentation, containment, or removal) to create or maintain suitable habitat for desired species of animals and plants. [Erik Kiviat (2013). Ecosystem services of Phragmites in North America with emphasis on habitat functions. AoB Plants, on-line 18 Feb 2013.] [Photo: Creek bordered by common reed (Phragmites australis), Empire Tract, Hackensack Meadowlands, New Jersey. Creeks like this are used by ducks in bad weather, muskrat, dragonflies, and several species of fishes. Photograph by Erik Kiviat.] Comment

Study finds effective methods to control weeds under guardrails

Zheljana Peric / WeedsNews4479 / June 4, 2013 / 10:27:48 PM EST / 0 Comments
[Roads & Bridges April 2013] -- For the past 50 years or more, mowing and herbicides have been the predominant methods used to manage USA's nationwide roadside vegetation. New environmental laws, reduced budgets and increased public interests necessitate finding more environmentally sensitive methods, incorporating new technologies, incurring lower maintenance costs and finding cost-effective alternatives to today’s methods of management of roadside vegetation. The Delaware Department of Transportation (DelDOT) is committed to reducing pesticide use in their transportation rights-of-way and therefore funded a study to look at various options for controlling vegetation under guardrails while maintaining functionality. The area adjacent to the guardrail must be kept clear of vegetation to allow clear visibility of the barrier. Robert Moosmann of Maine DOT explained that control of vegetation under and behind guardrails would restrict the buildup of debris, which includes sand and sediment that prevent proper sheet flow of water off the road surface. With unmanaged vegetation, rills develop behind the guardrail as water channels to points of least resistance and results in erosion. But low-growing grasses planted under guardrails can increase biofiltration of storm-water runoff. Some states use mowing and hand trimming (mechanical control) as their primary management tool. Mowing, while evaluated as the most cost efficient currently available option in a California study, is often not feasible because of mower size and the inability to maneuver the mowing head around and under the guardrails. Hand trimming is time consuming and labor intensive as well as dangerous because of operator exposure working between traffic and the barriers. With cultural control, a plant species is established that will compete with and suppress growth of the unwanted brush. A dense stand of low-growing plants is referred to as living mulch. White clover was tested as living mulch but did not establish successfully enough to compete with weeds. Where maintenance with residual herbicides has been practiced over a number of years, the lingering presence of residual herbicides may limit desirable plant growth, favoring the most aggressive and often undesirable species. Creating and encouraging stable, low-maintenance vegetation is a more permanent vegetation-management strategy and should be the goal for all rights-of-way. [Photo: The study revealed that zoysiagrass sod provided a competitive, low maintenance vegetative cover under guardrail.] Comment

Is teaching cows to eat weeds a beneficial weed control technique?

Zheljana Peric / WeedsNews4475 / June 2, 2013 / 8:35:04 PM EST / 0 Comments
[On Pasture by Cathy Voth May 27 2013] -- One of the common questions I get from folks who hear me talk about training livestock to eat weeds is whether or not it is a good way to control weeds. For the answer, I’ll share what was in my head when I started trying to figure out the process for teaching animals to try a new food. 1. Using herbicides is expensive. Not only is there the cost of the chemical itself, but there’s the cost of the equipment to apply it, along with labor for learning about how to use it, sometimes getting certified to use it, then applying it. And it’s not a one time cost, but something that is repeated over and over again. 2. Herbicides don’t appear to be working. In spite of our best efforts, weed populations continue to expand at about 14% per year. So it seems like we’re pouring good money after bad. 3. Producers are often low on forage, particularly in arid areas or during drought. But weeds are always there, even in drought, AND they’re often higher in nutritional value than traditional grass-based forage. 4. Margins are pretty low in agriculture and the producers who can reduce costs are the ones who are going to be successful. 5. SO – If I can figure out how to get a cow to eat a weed, producers can eliminate the expense for weed control, they’ll have more feed at no additional cost, cows gain weight more rapidly when they eat higher protein foods, so farmers will be able to raise more, fatter cows more cheaply and they’ll make more money doing it. [Photo: This calf is eating musk thistle, just like her mom taught her to do.] Continue reading …

Preventing weeds through duck-rice cultivation

Zheljana Peric / WeedsNews4473 / June 2, 2013 / 8:18:35 PM EST / 0 Comments
Abstract: Rice-duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. The duck's secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich the species diversity and improve the field environment. Rice-duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers, the control effects can be up to 98.47% and 100% respectively; also has effects on the control of chilo suppressalis ,tryporyza incertulas, and the rice leafrollers. Notable control results are found on the sheath blight, while the effects on other diseases are about 50%. It puts the harm of weeds under primary control, the prevention on weeds is sequenced by broad-leaf weeds > sedge weeds > gramineae weeds. Contents of SOM, N, P and K are improved by the system, nutrients utilization is accelerated resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1% to 2% and duck fodder is saved in this system. Besides, there is obvious economic benefit. Compared to conventional rice cultivation, rice-duck cultivation shows great benefits on ecologic cost and economic income. [Pan Long, Huang Huang, Xiaolan Liao, Zhiqiang Fu, Huabin Zheng, Aiwu Chen& Can Chen (2013). Mechanism and capacities of reducing ecological cost through rice-duck cultivation. Journal of the Science of Food and Agriculture, online 22 May, DOI: 10.1002/jsfa.6223] Comment

Aspergillus alliaceus, a new potential biological control of the root parasitic weed Orobanche

Zheljana Peric / WeedsNews4471 / June 2, 2013 / 7:58:04 PM EST / 0 Comments
Abstract: During extensive surveys in fields heavily infested by broomrape in the Trakya Region-Turkey, a different new fungus, Aspergillus alliaceus, was isolated from the infected broomrape. It is aimed to investigate whether or not it is really a pathogen for Orobanche. The fungi was exposed to a greenhouse environment in order to assess its pathogenicity and virulence against Orobanche cernua. In addition, infection tests on Orobanche seeds were also performed under laboratory conditions. The fungus was subjected using two different methods, exposure to a liquid culture with conidial solution and a sclerotial solid culture with fungal mycelia. Cytological studies were carried out at light, TEM and SEM levels. The results show that the sclerotial solid culture with fungal mycelia quickly caused necrosis and was more effective than the other type. It also greatly diminished attachments, tubercles, and caused the emergence of shoots and an increase in the total shoot number of Orobanche. In addition, both when the fungi was exposed to both soil and used to contaminate sunflower seeds, its pathogenicity was more effective. Consequently, it was determined that A. alliaceus was an effective potential biological control of broomrape throughout its life cycle from dormant seed to mature plant. [Aybeke, M., Şen, B. and Ökten, S. (2013). Aspergillus alliaceus, a new potential biological control of the root parasitic weed Orobanche. Journal of Basic Microbiology, online 20 May 2013. doi: 10.1002/jobm.201300080] Comment

Goats to manage weeds at Chicago airport

David Low / WeedsNews4462 / May 21, 2013 / 9:52:58 PM EST / 0 Comments
[TriplePundit 15 May 2013 by Tina Casey] -- Chicago’s Department of Aviation announced that O’Hare International Airport is getting its own herd of goats to help manage vegetation, so even though the pilot project hasn’t even gotten off the ground yet it’s already a whopping success. That’s because, although the airport does expect to realize some concrete bottom line benefits from goat-powered landscaping, one goal of the project was to raise public awareness about environmental stewardship. That might seem to be a curious message for a massive, sprawling, energy-sucking facility like an airport to promote, but take a look at O’Hare’s other activities and you can see how just about any business can seize the initiative and transition its operations to a more sustainable future. The goat contract for “sustainable management grazing services” was awarded to a Chicago company called Central Commissary Holdings, LLC, which already has a grazing herd of about 25 goats at the ready near the city. Once enough spring foliage fills out at the airport, the goats will be moved there. For now, the pilot project consists of just 120 acres (the airport covers more than 7,000 acres in all), but these are key acres. They include creeks, streams and roadways where hilly areas create obstacles for motorized equipment. The goats are tasked with trimming down densely growing scrub, including poison ivy and other noxious or invasive species, while helping the airport to save fuel, cut down on herbicides and greenhouse gas emissions, reduce the potential for soil erosion, and of course, “naturally recycle nutrients as fertilizer.

Why wheat farmers could reduce chemical inputs: evidence from social, economic, and agronomic analysis

David Low / WeedsNews4461 / May 21, 2013 / 4:53:12 PM EST / 0 Comments
Abstract: Though European policies recommend pesticide reduction, most farmers still manage their crops with a high level of chemical inputs, notably in arable crop-based systems. Factors influencing farmers’ practices and the reasons why they do not adopt alternative techniques are not well-known. Actual reports on that topic are based on monodisciplinary analyses either in agronomy, sociology, or economics, whereas farmers’ motives are most probably manifold. Therefore, we surveyed winter wheat agricultural practices to understand the factors influencing the choice of crop management plans implemented by farmers. We interviewed 71 farmers in the French Department of Eure-et-Loir. Results revealed three main types of practices depending on inputs and wheat yield: (1) 29 % of farmers use low levels of inputs and get low yield, (2) 38 % of farmers use medium levels of inputs and get high yield, (3) 33 % of farmers use high levels of inputs and get medium yield. We found that the medium-input type is the most efficient with better economic results whatever the wheat price. On the other hand, the high-input type has a lower economic performance. We showed that farm profile, individual motives, and social commitments explain the level of input use. High-input practices are often implemented by farmers who have less family labor availability and who rarely join extension groups, whereas low-input practices are conducted by farmers bearing civic responsibilities and showing environmental awareness. The novelty of our study is to use a multidisciplinary analysis to take into account agronomic, social, and economic factors. [Stéfanie Nave, Florence Jacquet & Marie-Hélène Jeuffroy (2013). Why wheat farmers could reduce chemical inputs: evidence from social, economic, and agronomic analysis. Agronomy for Sustainable Development, ]

USA removes obstacles to the growth of organic production

David Low / WeedsNews4460 / May 21, 2013 / 2:22:44 PM EST / 0 Comments
[PR Newswire 14 May 2013] WASHINGTON-- Speaking to member-attendees of the Organic Trade Association's (OTA's) recent policy conference, Secretary of Agriculture Tom Vilsack officially recognised the unique production system covering U.S. organic agriculture, and announced guidance to remove agency obstacles to its continued growth. "Organic is not the 'same as.' It is its own separate commodity and needs to be treated as such. I'm committed to that," Secretary Vilsack told policy attendees. (See USDA's press release). He added that USDA will be providing new guidance and direction on organic production to all USDA agencies directing them to recognise the distinct nature of USDA certified organic production and organic goods, and to take into account the documentation and inspection required for organic certification when considering organic operations' eligibility for USDA programs and policies. The landmark guidance document Vilsack alluded to points out that through the National Organic Program (NOP), USDA has helped farmers and other operations create an industry now encompassing over 17,000 organic businesses in the United States and achieving $35 billion in U.S. retail sales. In fact, organic ranks fourth in U.S. food and feed crop production at farm-gate values when viewed as a distinct category. "Organic production models may provide alternative solutions to current agricultural challenges, and it is the agency's responsibility to develop diversity in research and alternatives for all producers," the guidance points out. Importantly, the guidance also establishes that agency administrators review their goals and report on actions taken towards achieving the USDA strategic goals related to organic agriculture. Organic production and commerce are bright spots in the American marketplace of innovation and entrepreneurship, and particularly can contribute to USDA's goals for rural economic development. In recognition of its potential, the 2010 USDA Strategic Plan called for an increase of 25 percent in U.S. certified organic businesses by 2015.

Evaluation of weed composts on yield and quality of fodder maize

David Low / WeedsNews4457 / May 21, 2013 / 1:28:15 PM EST / 0 Comments
Abstract: Composts were prepared from the weeds viz. Cassia tora L., Ipomoea muricata L. and Hyptis suaveolens (L.) Poit, and incorporated into the top soil by disking. Fodder maize (Zea mays L.) var. ‘African Tall’ (Mahalaxmi) was cultivated on the manure amended soils, and their effect on growth of maize was studied and compared with recommended dose of chemical fertilizers and control (no fertilizer application). The compost prepared from Ipomoea was found suitable for higher productivity of fodder maize. Highest dry matter yield was recorded due to the treatment of mixed compost prepared from the mixture of three weeds.[Sanap S.B. & Jadhav Bharati (2013). Evaluation of weed composts on yield and quality of fodder maize. Bioinfolet - A Quarterly Journal of Life Sciences, 10(2), 543-546. ]

Ecological impacts of invasive African olive (Olea europaea ssp. cuspidata) in Cumberland Plain Woodland, Sydney, Australia

David Low / WeedsNews4454 / May 6, 2013 / 6:02:39 AM EST / 0 Comments
Abstract: African olive (Olea europaea ssp. cuspidata) is a small evergreen tree which has become highly invasive at a landscape scale in the western Sydney and Hunter Valley regions of New South Wales, Australia. African olive invasion results in the formation of a dense and permanent mid-canopy in grassy woodland vegetation. We investigated the relationship between African olive and native species establishment, abundance and diversity, using field surveys and a manipulative shading experiment. There were 78% fewer native species beneath African olive canopy in the field compared to uninvaded woodland sites. The shading experiment showed that simulated dense African olive shade levels produced the lowest dry weight for the three native species studied, with simulated canopy edge light providing optimal conditions for the native shrub Bursaria spinosa and African olive. Dense African olive shade levels produced the highest mortality rate for native species; however, African olive was able to maintain an 88% survival rate under dense canopy shade. This study confirms the adaptability of African olive and its capacity to decrease native plant diversity and substantially modify native vegetation at the community level. [CUNEO, P. and LEISHMAN, M. R. (2013). Ecological impacts of invasive African olive (Olea europaea ssp. cuspidata) in Cumberland Plain Woodland, Sydney, Australia. Austral Ecology, 38: 103–110. doi: 10.1111/j.1442-9993.2012.02382.x]

A new method to evaluate the weed-suppressing effect of mulches: a comparison between spruce bark and cocoa husk mulches

David Low / WeedsNews4452 / May 5, 2013 / 8:21:49 PM EST / 0 Comments
Abstract: To suppress weeds in an apple (Malus sp.) orchard, we placed spruce (Picea spp.) bark mulch and cocoa (Theobroma cacao) husk mulch for 3 months in thicknesses of 0, 2.5, 5, 10 and 15 cm. To assess the development of weed cover, an innovative use of log-logistic dose–response models was applied, with mulch thickness as the independent variable. Weed cover was measured by non-destructive image analysis by estimating the relationship between the number of green pixels and the total number of pixels in each experimental plot. The thickness of mulch layer required to attain a 50 and 90% weed suppression (ED50 and ED90) differed significantly within and between mulch types. In all except one instance, the cocoa mulch was superior in suppressing weeds. This method was useful for the evaluation, but further research is needed to give a more general conclusion about the suppression ability of the two mulches under other climatic and growing conditions.[Arentoft BW, Ali A, Streibig JC, Andreasen C. (2013). A new method to evaluate the weed-suppressing effect of mulches: a comparison between spruce bark and cocoa husk mulches. Weed Research, 53(3), 169–175]

Leftover biomass in Dutch flower bulb production can be used as a source of allelochemicals against weeds

David Low / WeedsNews4442 / April 29, 2013 / 9:10:33 AM EST / 0 Comments
Abstract: A major problem in flower bulb cultivation is weed control. Synthetic herbicides are mainly used, although they cause a range of problems, and integrated weed control through application of naturally occurring allelochemicals would be highly desirable. Flower bulb production creates large amounts of leftover biomass. Utilizing this source for weed control may provide new applications of the bulb crops. We therefore screened 33 flower bulb extracts for allelochemical activity against weeds. Several methanol and chloroform extracts were observed to inhibit germination and growth of Senecio vulgaris L. and Lolium perenne L., as representatives of di- and mono-cotyledonous weeds, respectively. Narciclasine was identified as the bioactive compound in Narcissus. The extract of Amaryllis belladonna L. was equally active, but did not contain any narciclasine. Bioassay-guided fractionation of the A. belladonna extract resulted in the identification of lycorine as the bio-active compound. The IC50 measured for radicle growth inhibition was 0.10 μM for narciclasine and 0.93 μM for lycorine, compared to 0.11 mM of chlorpropham, a synthetic herbicide. Therefore, the leftover biomass from the spring bulb industry represents an interesting potential source for promising allelochemicals for further studies on weed growth inhibition. [Dinar S. C. Wahyuni , Frank van der Kooy, Peter G. L. Klinkhamer, Rob Verpoorte & Kirsten Leiss (2013). The use of bio-guided fractionation to explore the use of leftover biomass in Dutch flower bulb production as allelochemicals against weeds. Molecules, 18, 4510-4525] [Daffodil fields in Holland/Photo by Deb Wiley] Comment

Environmental stewardship outcomes from year-long invasive species restoration projects in middle school

David Low / WeedsNews4440 / April 29, 2013 / 9:00:11 AM EST / 0 Comments
Abstract: To investigate the impacts of long term targeted invasive plant stewardship projects on students' subsequent stewardship attitudes , a pre-post test control experiment for program effects and a post-test control experiment for school effects was conducted. The resulting scores from two science classes that participated in year long invasive plant and restoration activities were compared with those from three comparable classes at a linked school that did not participate in any of these activities. Students in the experimental classes showed overall significantly higher scores compared with the control classes. These attitude scores were then divided into two indexes; sense of personal effectiveness, and attitudes of caring for particular places. Students in the experimental group showed increases in both, as compared with the controls. Parent and student focus groups were conducted at the end of the academic year. The resulting comments provide evidence for actual behavior change outside of the school environment. Analysis showed that any student, especially those in the control classes in the traditional middle school, indicating they had prior exposure to nature stewardship projects showed significantly higher scores than students who did not. The results underscore the value of having students involved in real world stewardship projects, especially those of a long term nature. [Marion Dresner and Kelly A. Fischer (2013). Environmental stewardship outcomes from year-long invasive species restoration projects in middle school. Invasive Plant Science and Management, 12 March 2013] Comment

Spray-on-mulch helps apple trees grow and prevents weeds

David Low / WeedsNews4439 / April 29, 2013 / 6:19:58 AM EST / 0 Comments
Abstract: Apple producers are eager to grow fruit using fewer chemical inputs that can harm the environment. Finding cost effective and sustainable methods of weed control that encourage high yields of quality fruit is a goal amongst fruit producers. Due to improved recycling programs, organic mulch (made from any-thing that can decay, including grain, wood, paper, etc.) is increasingly available. It is considered effective at controlling weeds and improving soil health, but is seen as more costly than traditional chemical pesticides because of the labour-intensive method of application. However, if mulch could be sprayed onto orchards, it would be less expensive than traditional mulching. Previous research has shown that spray-on-mulch (SOM) can reduce the growth of most weeds. The goal of this research was to develop and evaluate a new way to apply SOM to make it more convenient and less costly to apply. The experiment involved 4 different apple species, grown in separate orchards. SOM (a combination of waste newsprint, chopped straw, non-coloured shredded paper, and water) was sprayed adjacent to trees using a mechanical sprayer. For each apple species, up to nine different methods of application were used. Standard levels of irrigation and fertilizers were used in all treatments. Researchers measured soil moisture and temperature, tree growth, amount of fruit produced and the number and types of weeds. The use of SOM increased soil moisture and made seasonal soil temperatures less extreme. When SOM was included in treatments, trees grew very well except when a residual herbicide was added to SOM. All trees with SOM treatments produced more fruit than trees with glyphosate treatments, except when SOM was sprayed on top of plastic sheeting. All SOM treatments outperformed glyphosate in controlling weeds. Adding a sticky substance to SOM provided only slightly improved weed control. SOM treatments also increased levels of potassium in leaves more effectively than glyphosate. Fruit nutrients were equivalent across treatments. [Cline, J., Neilsen, G., Hogue, E., Kuchta, S., Neilsen, D. (2011). Spray-on-mulch technology for intensively grown irrigated apple orchards: Influence on tree establishment, early yields, and soil physical properties. Journal of HortTechnology, 21(4) 398-411] Comment

The runaway weed: costs and failures of Phragmites australis management in the USA

David Low / WeedsNews4438 / April 27, 2013 / 12:12:22 AM EST / 0 Comments
Abstract: While public funding of invasive species management has increased substantially in the past decade, there have been few cross-institutional assessments of management programs. We assessed management of Phragmites australis, a problematic invader of coastal habitats, through a cross-institutional economic survey of 285 land managers from US public and private conservation organizations. We found that from 2005 to 2009, these organizations spent >$4.6 million per year on P. australis management, and that 94% used herbicide to treat a total area of ∼80,000 ha. Despite these high expenditures, few organizations accomplished their management objectives. There was no relationship between resources invested in management and management success, and those organizations that endorsed a particular objective were no more likely to achieve it. Our results question the efficacy of current P. australis management strategies and call for future monitoring of biological management outcomes. [Laura J. Martin & Bernd Blossey (2013). The runaway weed: costs and failures of Phragmites australis management in the USA. Estuaries and Coasts, 36(3), 626-632] Comment

Viability of aquatic plant fragments following desiccation

David Low / WeedsNews4437 / April 26, 2013 / 11:41:48 PM EST / 0 Comments
Abstract: Desiccation following prolonged air exposure challenges survival of aquatic plants during droughts, water drawdowns, and overland dispersal. To improve predictions of plant response to air exposure, we observed the viability of vegetative fragments of ten aquatic plant species (fanwort, coontail, common elodea, Brazilian elodea, parrotfeather, variable-leaf watermilfoil, Eurasian watermilfoil, curlyleaf pondweed, Richardson's pondweed, and hydrilla) following desiccation. We recorded mass loss, desiccation rate, and plant fragment survival across a range of air exposures. Mass loss accurately predicted viability of aquatic plant fragments upon reintroduction to water. However, similar periods of air exposure differentially affected viability between species. Understanding viability following desiccation can contribute to predicting dispersal, improving eradication protocols, and disposing aquatic plants following removal from invaded lakes or contaminated equipment. [Matthew Barnes, Christopher L. Jerde, Doug Keller, W Lindsay Chadderton, Jennifer G. Howeth, and David M. Lodge (2013). Viability of aquatic plant fragments following desiccation. Invasive Plant Science and Management, on-line 17 Jan.] Comment

Glyphosate: a pathway to modern disease

David Low / WeedsNews4432 / April 26, 2013 / 10:20:29 AM EST / 0 Comments
Abstract: Glyphosate, the active ingredient in Roundup®, is the most popular herbicide used worldwide. The industry asserts it is minimally toxic to humans, but here we argue otherwise. Residues are found in the main foods of the Western diet, comprised primarily of sugar, corn, soy and wheat. Glyphosate's inhibition of cytochrome P450 (CYP) enzymes is an overlooked component of its toxicity to mammals. CYP enzymes play crucial roles in biology, one of which is to detoxify xenobiotics. Thus, glyphosate enhances the damaging effects of other food borne chemical residues and environmental toxins. Negative impact on the body is insidious and manifests slowly over time as inflammation damages cellular systems throughout the body. Here, we show how interference with CYP enzymes acts synergistically with disruption of the biosynthesis of aromatic amino acids by gut bacteria, as well as impairment in serum sulfate transport. Consequences are most of the diseases and conditions associated with a Western diet, which include gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease. We explain the documented effects of glyphosate and its ability to induce disease, and we show that glyphosate is the “textbook example” of exogenous semiotic entropy: the disruption of homeostasis by environmental toxins. [Anthony Samsel and Stephanie Seneff (2013). Glyphosate’s suppression of cytochrome P450 enzymes and amino acid biosynthesis by the gut microbiome: Pathways to modern diseases. Entropy, 15.] Comment

UBC researchers weed out ineffective biocontrol agents

David Low / WeedsNews4423 / April 21, 2013 / 9:39:48 PM EST / 0 Comments
[UBC APRIL 17, 2013] -- ‘Keep it simple’ is a good rule of thumb when designing biocontrol programs to combat weeds and invasive plants, according to a meta-analysis of studies by UBC biodiversity experts. Biocontrol programs use an invasive plant’s natural enemies (insects and pathogens) to reduce its population. Most biocontrol programs combine many different enemies – typically about three different species, but sometimes as many as 25 – with the hope that at least one will prove effective. But more isn’t necessarily better. Some combinations of enemy species can actually end up competing or interfering with each other, instead of attacking the weed. "It's important to get the right combination of biocontrol agents, as testing species is costly and time-consuming, and no amount of testing can eliminate the risk that something unexpected will occur with the introduction of a new species," says Andrea Stephens, lead author on the paper published in the Proceedings of the Royal Society B this week. Until now, biocontrol managers have chosen weed enemies to release based on the individual effect of each species in isolation, with little thought to overall combinations. “Our study suggests that this approach can lead to ineffective biocontrol, because the interactions between the released enemies can reduce the overall effectiveness of biocontrol,” says Diane Srivastava, author on the paper and professor in UBC's Biodiversity Research Centre. Of the 75 combinations the researchers investigated, about a quarter appeared to have a smaller combined impact than expected. The researchers suggest simple species combination rules could improve the effectiveness of biocontrol programs. The study recommends avoiding combinations of species that attack the same part of the plant at the same time, as well as assessing the impact of species attacking reproductive structures. “In most cases damage from different species of insects was independent,” says Judith Myers, Professor Emerita and author on the paper. “But insect species feeding on the seeds of plants tend to compete and so multiple introductions can be detrimental.” One of the studies researchers analyzed focused on three agents (two species of weevils and a fly) that have been released in western North America to control two species of invasive plants, diffuse and spotted knapweed. The weevils consume the fly larvae, nullifying the effectiveness of the fly. [Photo of Larinus minutus, a weevil introduced to combat the invasive diffuse knapweed in western North America. The effectiveness of the weevil and other biological agents may be reduced when species combinations work against each other.] Comment

Canada's organic market now worth $3.7 billion - Growth driven by broad-scale support of organic foods

David Low / WeedsNews4422 / April 21, 2013 / 9:18:55 PM EST / 0 Comments
[CNW April 11, 2013] OTTAWA -- Canada's organic market grew to $3.7 billion in 2012, with national sales of certified organic food and non-alcoholic beverages reaching $3 billion. The value of the Canadian organic food market has tripled since 2006, far outpacing the growth rate of other agri-food sectors. A diverse consumer base is driving the sector, with 58% of all Canadians buying organic products every week. "At the industry's urging, the government implemented strict national standards and label requirements in 2009 to uphold consumer confidence in organic claims" said Matthew Holmes, Executive Director of the Canada Organic Trade Association, "so it's tremendously gratifying to see this result in such strong market growth and continued consumer commitment to organic." In BC, the focus of the first phase of research, two-thirds of consumers—and over three-quarters of Vancouverites—are buying organic groceries weekly. BC generated 23% of the value of the national organic food and beverage market, with strong sales across distribution channels. "We are pleased to see growing consumer demand and impressive sales growth from mainstream retail to direct-to-consumer channels," stated Rebecca Kneen, Co-President of the Certified Organic Associations of BC. Funding for this research has been provided through Loblaw Companies, Taste of Nature, UNFI Canada, Whole Foods Market and the Organic Sector Development Program (OSDP). Funding for the OSDP comes from Agriculture and Agri-Food Canada's Canadian Agricultural Adaptation Program, which is delivered by the Investment Agriculture Foundation in British Columbia. The full BC report and national highlights are available at www.ota-canada.ca. [Photo credit: Wikipedia] Comment

Making peace with daisies

David Low / WeedsNews4420 / April 21, 2013 / 8:43:56 PM EST / 0 Comments
Abstract: Ox-eye daisies (Leucanthemum vulgare) and scentless chamomile (Matricaria perforata) were intentionally introduced to North America from other continents for aesthetics, agriculture, medicinal use, or culinary pleasure, but have also been labeled as noxious weeds in the USA and Canada. While working to eradicate these plants as part of a mine land restoration project in Colorado, botanist Katherine Darrow contemplates some of the ethical and biological dilemmas inherent to the task of eradicating plants we have been taught to loathe. "With all of their benefits to balance out their proclivity to colonize and reproduce, isn’t there a way we could make peace with daisies, rather than label them as botanical terrorists that must be destroyed? Is this “war on weeds” a battle we can even win? What are some compromises that might dissolve the conflict and allow co-existence based on mutual respect? Can we make agreements to disagree while honoring the basic rights of other living beings…even if they are only plants?" As restoration ecologists, these are some of the questions we may choose to explore if we wish to approach the task of controlling other species with an attitude of non-violent conflict resolution. Because, ultimately, “we will all be pushing up, rather than pulling up daisies.Full-text available here. Comment

Detection of herbicides in the urine of pet dogs following home lawn chemical application

David Low / WeedsNews4419 / April 19, 2013 / 10:55:03 PM EST / 0 Comments
Abstract: Exposure to herbicide-treated lawns has been associated with significantly higher bladder cancer risk in dogs. This work was performed to further characterize lawn chemical exposures in dogs, and to determine environmental factors associated with chemical residence time on grass. In addition to concern for canine health, a strong justification for the work was that dogs may serve as sentinels for potentially harmful environmental exposures in humans. Experimentally, herbicides [2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxypropionic acid (MCPP), dicamba] were applied to grass plots under different conditions (e.g., green, dry brown, wet, and recently mowed grass). Chemicals in dislodgeable residues were measured by LC-MS at 0.17, 1, 24, 48, 72 h post treatment. In a separate study, 2,4-D, MCPP, and dithiopyr concentrations were measured in the urine of dogs and in dislodgeable grass residues in households that applied or did not apply chemicals in the preceding 48 h. Chemicals were measured at 0, 24, and 48 h post application in treated households and at time 0 in untreated control households. Residence times of 2,4-D, MCPP, and dicamba were significantly prolonged (P < 0.05) on dry brown grass compared to green grass. Chemicals were detected in the urine of dogs in 14 of 25 households before lawn treatment, in 19 of 25 households after lawn treatment, and in 4 of 8 untreated households. Chemicals were commonly detected in grass residues from treated lawns, and from untreated lawns suggesting chemical drift from nearby treated areas. Thus dogs could be exposed to chemicals through contact with their own lawn (treated or contaminated through drift) or through contact with other grassy areas if they travel. The length of time to restrict a dog's access to treated lawns following treatment remains to be defined. Further study is indicated to assess the risks of herbicide exposure in humans and dogs. [Deborah W. Knapp et al. (2013). Detection of herbicides in the urine of pet dogs following home lawn chemical application. Science of The Total Environment, Volumes 456–457, 1 July 2013, Pages 34–41] Comment

Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control

David Low / WeedsNews4417 / April 19, 2013 / 10:34:50 PM EST / 0 Comments
Abstract: Many public authorities rely on the use of non-chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order to investigate the efficacy of four non-chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air/flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed cover was measured every second week using a 75 cm × 75 cm quadrat divided into 100 squares. On the control areas, a rapid increase in weed cover was observed, whereas weed cover could be kept below 2% by 2–7 treatments per year, depending on control method. On average, the following numbers of treatments per year were required: glyphosate 2.5, hot water 3, flames 5, hot air/flames 5.5 and steam 5.5 treatments. The results demonstrate that the weed control should be adjusted to the prescribed quality for the traffic islands by regularly assessing the need for weed control. They also show that tailored treatments can reduce the number of required non-chemical treatments per year. [Rask A M, Larsen S, Andreasen C & Kristoffersen P (2013). Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control. Weed Research, on-line 16 April] Comment

Higher soybean production using honeybee and wild pollinators, a sustainable alternative to pesticides and autopollination

David Low / WeedsNews4416 / April 19, 2013 / 9:45:54 PM EST / 0 Comments
Abstract: This is the first report showing that using honeybee (Apis mellifera) and wild pollinators complementary pollination can enhance soybean productivity (Glycine max). Current industrial production of soybean involves autopollination and high loads of pesticides. Therefore, growers have neglected possible biotic pollination despite suggestions that soybean benefit from insect pollinators. Reports advocating possible biotic pollination are based on experiments where bees are caged with flowering plants and the absence of pesticides, thus not in field conditions. Therefore, here we compared in field conditions soybean yield produced (1) independently of biotic pollinators, (2) with wild pollinators and (3) with honeybee colonies. Results showed an increase of +6.34 % of soybean yield in areas where wild pollinators had free access to flowers. The introduction of honeybee colonies further raised the yield of +18.09 %. Our findings therefore show that, though soybean is autogamous, allowing pollination by wild pollinators leads to higher yields. Moreover, adding honeybee mitigates pollination deficits and improves yield compared to current practices. [Marcelo de O. Milfont, Epifania Emanuela M. Rocha, Afonso Odério N. Lima & Breno M. Freitas (2013). Higher soybean production using honeybee and wild pollinators, a sustainable alternative to pesticides and autopollination. Environmental Chemistry Letters, April 2013] Comment

Bioherbicides: A more sustainable future for weed control

David Low / WeedsNews4404 / April 14, 2013 / 2:49:13 PM EST / 0 Comments
[Marrone Bio Innovations 04 April 2013 Originally published on Grainews by Lisa Guenther] -- While high costs are still a hurdle to overcome, bioherbicides are in the works and could be a weapon in the struggle against herbicide resistance. Researchers in Canada and the United States are developing bioherbicides that will not only give organic and conventional farmers more weed control options, but also, in some cases, control herbicide-resistant weeds. Bioherbicides are synthetically produced compounds identical to chemicals found in nature. They may be sourced from micro-organisms or plants. Bioherbicides can also include whole microorganisms that infect weeds. Currently there are no bioherbicides registered for use on agricultural crops in Canada, but researchers with Agriculture and Agri-Food Canada (AAFC) are working to change that … read more

US residents push city to stop using toxic chemicals in local parks

David Low / WeedsNews4403 / April 14, 2013 / 2:26:32 PM EST / 0 Comments
[connectstoughton.com by Bill Livick 08 April 2013] -- Three local Wisconsin women are spearheading an effort to persuade city officials to abandon a plan to use herbicides in Stoughton parks and athletic fields beginning this spring. After learning of the plan about two weeks ago, Sylvia Lawrence, Gennifer Weaver and Sara Downie – all mothers with young children – contacted friends in the city who share their concerns. They established a grassroots group opposed to using chemicals to control broadleaf plants such as dandelions and clover. They also offered to help maintain park lawns and playing fields and have encouraged the city to adopt alternatives to chemical applications. The three and about two-dozen supporters calling themselves Naturally Stoughton-Cultivating Sustainable Solutions attended a Public Works Committee meeting last Monday to question the new policy. They hope the city can find organic solutions to what some people are considering a significant weed problem. [Photo by Bill Livick: From left, city residents Gennifer Weaver, Sylvia Lawrence with baby Felix, Hannah Lawrence, Eve Downie, Sara Downie and Drew Downie gather at Veterans Park, in which the women hope city officials will not use chemicals to control weeds.] Comment

Improved understanding of weed biological control safety and impact with chemical ecology: A review

David Low / WeedsNews4399 / April 14, 2013 / 1:52:57 PM EST / 0 Comments
Abstract: We review chemical ecology literature as it relates to biological control of weeds and discuss how this means of controlling invasive plants could be enhanced by the consideration of several well-established research approaches. The interface between chemical ecology and biological control of weeds presents a rich opportunity to exploit potentially coevolved relationships between agents and plants where chemical factors mediating interactions are important. Five topics seem relevant, which if implemented could improve the predictability of host range determination, agent establishment, and impact on the target weed. (1) The host secondary plant chemistry and a potential biological control agent's response to that chemistry can be exploited to improve predictability of potential agent host range. (2) Evolutionary changes may occur in secondary plant chemistry of invasive weeds that have been introduced to novel environments and exposed to a new set of biotic and abiotic stressors. Further, such a scenario facilitates rapid evolutionary changes in phenotypic traits, which in turn may help explain one mechanism of invasiveness and affect the outcome of biological control and other management options. (3) Herbivores can induce production of secondary plant compounds. (4) Variability of weed secondary chemistry which, either constitutive or inducible, can be an important factor that potentially influences the performance of some biological control agents and their impact on the target weed. (5) Finally, sequestration of secondary plant chemistry may protect herbivores against generalist predators, which might improve establishment of a biological control agent introduced to a new range and eventually impact on the target weed. Recognition of these patterns and processes can help identify the factors that impart success to a biological control program. [Gregory S. Wheeler and Urs Schaffner (2013). Improved understanding of weed biological control safety and impact with chemical ecology: A review. Plant Science and Management, 6(1), 16-29.] Comment

Spatial pattern and severity of fire in areas with and without buffel grass (Cenchrus ciliaris) and effects on native vegetation in central Australia

David Low / WeedsNews4398 / April 14, 2013 / 1:42:30 PM EST / 0 Comments
Abstract: The spread of buffel grass (Cenchrus ciliaris) in semi-arid Australia in recent decades has substantially increased ground cover and fuel loads, particularly in open woodland vegetation communities. The resulting alteration of fire regimes may be the most significant impact of buffel invasion on ecological communities in these areas. Broad scale management of buffel grass is currently not an option in Australia but it is becoming increasingly relevant to assess the benefits of restoring areas of native vegetation where preventing buffel grass invasion is no-longer possible. We managed buffel grass in a series of experimental plots from 2008–2012. In June and August 2011, two unplanned fires burnt through the plots providing a unique opportunity to compare the outcome of wildfire, including the spatial pattern of fire, and the effect on ground vegetation and on a long-lived, perennial overstorey species, in replicated managed and unmanaged plots. The area of ground that remained unburnt was much greater in managed plots (with predominantly native vegetation) than unmanaged (predominantly buffel grass) plots and where the managed plots did burn the fire was more patchy. This had direct implications for the richness of ground layer plant taxa following fire and the extent to which overstorey trees were exposed to fire. Fire increased pre-existing differences in the number of taxa in the ground level vegetation, an effect that persisted for the duration of our study, suggesting that fire accelerates direct negative competitive effects between buffel grass and native grasses and forbs. Hakea divaricata(fork-leafed corkwood) trees in unmanaged buffel grass sites suffered higher burn intensities, and their long-term viability at this location is likely to be threatened if fires fuelled by buffel grass continue. Our results demonstrate clear benefits of removing fire-enhancing invasive plants from areas of high conservation value. [Christine Schlesinger, Sarah White & Shane Muldoon (2013). Spatial pattern and severity of fire in areas with and without buffel grass (Cenchrus ciliaris) and effects on native vegetation in central Australia. Austral Ecology, on-line 28 March.] Comment

Plant biodiversity enhances bees and other insect pollinators in agroecosystems. A review

David Low / WeedsNews4397 / April 14, 2013 / 1:35:38 PM EST / 0 Comments
Abstract: Thirty-five percent of global production from crops including at least 800 cultivated plants depend on animal pollination. The transformation of agriculture in the past half-century has triggered a decline in bees and other insect pollinators. In North America, losses of bee colonies have accelerated since 2004, leaving the continent with fewer managed pollinators than at any time in the past 50 years. A number of factors linked to industrial modes of agriculture affect bee colonies and other pollinators around the world, ranging from habitat degradation due to monocultures with consequent declines in flowering plants and the use of damaging insecticides. Incentives should be offered to farmers to restore pollinator-friendly habitats, including flower provisioning within or around crop fields and elimination of use of insecticides by adopting agroecological production methods. Conventional farmers should be extremely cautious in the choice, timing, and application of insecticides and other chemicals. Here, we review the literature providing mounting evidence that the restoration of plant biodiversity within and around crop fields can improve habitat for domestic and wild bees as well as other insects and thus enhance pollination services in agroecosystems. Main findings are the following: (1) certain weed species within crop fields that provide food resources and refuge should be maintained at tolerable levels within crop fields to aid in the survival of viable populations of pollinators. (2) Careful manipulation strategies need to be defined in order to avoid weed competition with crops and interference with certain cultural practices. Economic thresholds of weed populations, as well as factors affecting crop–weed balance within a crop season, need to be defined for specific cropping systems. (3) More research is warranted to advance knowledge on identifying beneficial weed species and ways to sponsor them to attract pollinators while not reducing yields through interference. (4) In areas of intensive farming, field margins, field edges and paths, headlands, fence-lines, rights of way, and nearby uncultivated patches of land are important refuges for many pollinators. (5) Maintenance and restoration of hedgerows and other vegetation features at field borders is therefore essential for harboring pollinators. (6) Appropriate management of non-cropped areas to encourage wild pollinators may prove to be a cost-effective means of maximizing crop yield. [Nicholls Clara I. & Altieri Miguel A. (2013). Plant biodiversity enhances bees and other insect pollinators in agroecosystems. A review. Agronomy for Sustainable Development, 33(2), 257-274] Comment

Regulation of pesticides: A comparative analysis

David Low / WeedsNews4396 / April 14, 2013 / 1:25:48 PM EST / 0 Comments
Abstract: This paper compares three internationally representative regulatory frameworks for pesticides. We look first at the USA, which shifted regulatory powers from the US Department of Agriculture to the Environmental Protection Agency in the early 1970s, during a historical transition from a predominantly economic to a predominantly social regulatory model. The second country is Brazil, currently the world’s largest consumer of pesticides, followed by the USA in second place. In the early 1990s, Brazil’s new regulatory model adopted a troika of decision-making ministries (agriculture, health and environment), with the prevalence of economic over social-environmental interests. The third case is the regulatory framework adopted in 2011 by the EU, where shifts in risk-assessment criteria and corporate financial liability reveal a prevalence of concerns involving social-environmental regulation. [Victor Pelaez, Letícia Rodrigues da Silva & Eduardo Borges Araúj0 (2013). Regulation of pesticides: A comparative analysis. Science & Public Policy, online 04 April.] Comment

Weeds alter the evolutionary relationships of native species

David Low / WeedsNews4386 / April 5, 2013 / 8:55:13 PM EST / 0 Comments
Abstract: Plant populations are often adapted to their local conditions, including abiotic factors as well as the biotic communities with which they interact. Soil communities, in particular, have strong effects on both the ecology and evolution of plant populations. Many invasive plant species alter the ecological relationships between native plants and soil communities; however, whether invaders also alter the evolutionary dynamics between native plants and soils is less well known. Here I show that populations of a native annual, Pilea pumila, shift from being maladapted to adapted to their local soil community with increasing history of invasion by Alliaria petiolata, an invader known to alter microbial communities. Additionally, native populations showed a signal of adaptation to soils of particular invasion stages, independent of local coevolutionary dynamics. These results suggest that invasive species affect not only the ecological, but also the evolutionary relationships of native species. [Richard A. Lankau (2013). Species invasion alters local adaptation to soil communities in a native plant.] [Photo: Garlic mustard (Allaria petiolata) via Wikipedia] Comment

Sustainable agriculture encouraged in Taiwan

David Low / WeedsNews4385 / April 5, 2013 / 8:29:57 PM EST / 0 Comments
Abstract: As Taiwan has a dense population and only limited natural resources, the government began actively establishing a Taiwan’s sustainable development indicators (TSDI) system in 2003 to evaluate the progress towards sustainability. Commonly used pesticides could pose a risk of causing adverse effects to food sanitation, human health and the environment. Thus, the pesticide usage rate per hectare of farmland and the area of organic cultivation have been selected as agricultural sustainability indicators. The objective of this paper was to describe an analysis of current status of pesticide use and regulatory policy for environmental sustainability in Taiwan. Furthermore, it can be connected with the regulatory infrastructure, which has been established by the joint-venture of the central competent authorities (i.e., Council of Agriculture, Environmental Protection Administration, Department of Health, Ministry of Economic Affairs, and Council of Labor Affairs) for controlling and/or preventing pesticide distribution in the environment. The significant progress is that the residual pesticides have notably declined in the past decade, which was in parallel with the pesticide usage rate decreased and organic farming area increased. For example, total area of organically certified cropping in Taiwan has been increased from 900 hectares (ha) in 2001 to about 4,500 ha in 2010. Finally, some recommendations for the pollution prevention and toxicity reduction of pesticide use were also addressed to progress towards a sustainable agriculture in Taiwan. Comment

GMO herbicides 'not fit for purpose'

David Low / WeedsNews4383 / April 5, 2013 / 7:59:27 PM EST / 0 Comments
[The Huffington Post 24 March 2013] -- In the late 1990s while on a visit to the USA I saw my first GM crop - herbicide tolerant soybeans. As a farmer it was of great interest to see the latest agricultural technology being made available to US farmers. I have been a regular visitor to the USA since then and have seen how GM crops have developed over the years, I have also visited other countries who are growing GM crops among them India and South Africa. On that first visit farmers were keen to try out these new crops. The herbicide tolerant crops were going to make weed control so easy with the crops ability to withstand the total herbicide 'Roundup' (Glyphosate) one sprayer pass at the right time with Roundup would mean job done. Much easier than the old system of walking the fields seeing which weeds were growing then deciding which herbicide to use - and often it meant more than one herbicide to kill all the different weeds. All that was needed now was the one herbicide and job done, what was not to like about this new technology? But on my visit in 2002 I started to hear farmers say that it was now taking several passes with Roundup to kill the weeds and that they were using it at higher concentrations in order to kill the weeds. On visits over the next few years I started to hear about weeds which had become resistant to the Round Up which meant that farmers had to add other herbicides to the sprayer tank in order to kill those weeds. Read more …

Do conflict metaphors affect beliefs about managing “unwanted” plants?

David Low / WeedsNews4378 / April 5, 2013 / 7:26:17 PM EST / 0 Comments
Abstract: Woody plants have increased in density and extent in rangelands worldwide since the 1800s, and land managers increasingly remove woodland plants in hopes of restoring pre-settlement conditions and/or improved forage for grazing livestock. Because such efforts can be controversial, especially on publicly owned lands, managers often attempt to frame issues in ways they believe can improve public acceptance of proposed actions. Frequently these framing efforts employ conflict metaphors drawn from military or legal lexicons. We surveyed citizens in the Rocky Mountains region, USA, about their beliefs concerning tree-removal as a management strategy. Plants targeted for removal in the region include such iconic tree species as Douglas-fir and ponderosa pine as well as other less-valued species, such as Rocky Mountain juniper, that are common targets for removal nationwide. To test the influence of issue frame on acceptance, recipients were randomly assigned surveys in which the reason for conifer removal was described using one of three terms often employed by invasive biologists and land managers: “invasion”, “expansion”, and “encroachment”. Framing in this instance had little effect on responses. We conclude the use of single-word frames by scientists and managers use to contextualize an issue may not resonate with the public. [Cameron G. Nay & Mark W. Brunson (2013). A War of Words: Do conflict metaphors affect beliefs about managing “unwanted” plants? Societies, 3(2), 158-169] Comment  [Photo: IGI]

Weed-killer warps genes in fish embryos

David Low / WeedsNews4376 / April 5, 2013 / 7:03:21 PM EST / 0 Comments
[Purdue University 04 April 2013]An agricultural herbicide alters reproductive and neuroendocrine genes during embryonic development in fish, according to new research. “The exact connection to health outcomes is not defined, but we found gene alterations in our animal model when exposed to the level of atrazine that is deemed safe for drinking water,” says Jennifer Freeman, an Assistant Professor of Toxicology in the School of Health Sciences at Purdue University. “Also of concern was an increase in head length in the study’s young zebrafish when exposed to low doses of this widely used herbicide.” The researchers tested atrazine at three levels, 0.3 ppb, 3 ppb, and 30 ppb, by exposing developing zebrafish embryos. The 3 ppb level is the current safe level in drinking water, and the larger amount of atrazine tested represents what a worker may be exposed to or may be present in surface water. By using the zebrafish model the researchers were able to focus on the 72-hour embryonic development time, which mirrors human prenatal development. The researchers started by evaluating the more than 35,000 genes in the zebrafish’s genome. They found that two genes, CYP17A1 and SAMHD1, were changed in all three treatments. CYP17A1 plays a role in biosynthesis of steroid hormones and the conversion of androgens to estrogen, and SAMHD1 controls immune function. Also of concern was that 42 of the genes, including CYP17A1 and SAMHD1, were affected in the 30 ppb treatments as well as in the 3 ppb treatment. The LH gene, which produces the hormone that triggers ovulation, is another example of an affected gene at both 3 ppb and 30 ppb treatment levels. “There is a connection between the current legal level of atrazine and higher concentrations that need further study,” Freeman says. Freeman says continuing to investigate changes in genes associated with cancer is critical because there needs to be more information before determining if atrazine is a human carcinogen. Comment [Photo credit: Flickr]

Canadian pilot projects replace chemical poisons with goat herds

David Low / WeedsNews4374 / April 5, 2013 / 6:34:22 PM EST / 0 Comments
[CBC News 26 March 2013] -- Using goats rather than chemicals to control invasive species is more environmentally friendly and about 30 per cent cheaper. The B.C. Ministry of Transportation is piloting two projects in the B.C. Interior that will replace chemical poisons with herds of hungry goats. Donna Olsen, the environmental services coordinator at the Ministry of Transportation, says the pilots at two gravel pits are proving successful. "[There are] very visually stunning results,” she said. The goats actually prefer invasive species to the area's native grasses and they aren’t just greener than chemicals — the goats are also about 30 per cent cheaper. "We'd really like to continue it and there's a lot of interest from other stakeholders,” Olsen said. The animals are also used to control invasive species in the City of Kamloops."A lot of our areas are quite sensitive especially near water, where we can't even use chemicals there,” said Karla Hoffman, the city’s pest management coordinator.“So in most cases, they're one of the best choices."Hoffman says the goats have been successful in tackling invasive species.“They did help to bring the numbers of the plants down and therefore the amount of seed that would cause reproduction,” said Karla Hoffman, the integrated pest management coordinator in Kamloops.“Of course it's not a one-time process and we would need to put them back in there for subsequent years, just like we would for spraying, in order to get better control of the toadflax.” The province first used goats to control pests in 2012 and officials are in the process of gathering data on the treated plots to determine just how well the goats performed. Comment

Study details benefits of sustainable agriculture at state and local levels

David Low / WeedsNews4366 / March 27, 2013 / 9:23:37 PM EST / 0 Comments
[ATTRA 26 March 2013] -- To help guide the growing "Farm to Table" movement, PennEnvironment has released a new study that outlines how sustainable farming benefits the environment, economy, and public health--and offers a blueprint of state policies to improve the food system. The report, Healthy Farms, Healthy Environment: State and Local Policies to Improve Pennsylvania's Food System and Protect Our Land and Water (pdf) explains the myriad benefits of sustainable farming and offers policy solutions to take advantage of the growing consumer market for locally grown and organic products. The report identifies successful programs in other states and urges Pennsylvania's legislators to bring their success to the Commonwealth, as well as calling on state officials to renew funding for and expand successful sustainable agriculture programs. Some of the finding of the report include: Organic growing methods have been shown to reduce polluted runoff and energy consumption in agriculture, while boosting the carbon content of soils, according to experiments at the Rodale Institute organic farm laboratory in Kutztown, Pennsylvania. Consumption of fresh, local food – as opposed to processed food or produce from halfway around the globe – can reduce the amount of energy used in preserving and transporting food. Farmers can grow and market fresh peas with 60 percent less energy than frozen peas, and 75 percent less energy than packaging peas in an aluminum can. Sustainable farming can also help farmers keep farmland in production, despite development pressure, by increasing farm income – thereby protecting open land and the valuable ecosystem services it provides. Comment

Farmers' knowledge of the value of ecosystem services can help scientists

David Low / WeedsNews4365 / March 27, 2013 / 8:42:29 PM EST / 0 Comments
Abstract: Exploiting the complementarities between biological components in agricultural systems is presented as a solution to increase food production and decrease environmental problems. This amounts to maximizing the ecosystem services (i.e., the benefits human obtain from ecosystems) provided by biodiversity at the expense of the disservices (i.e., the nuisances human obtain from ecosystems). In recent years, science has produced significant results supporting this strategy, but their application in the field is dependent on stakeholders’ knowledge. This article therefore addresses two questions: What do stakeholders know about the services and disservices provided by biodiversity? Does this knowledge agree with scientific results? We address these questions by combining a literature review of 39 scientific articles and interviews with 8 farmers and 3 farm advisors in France. Scientific results and stakeholders’ knowledge both indicate that within- and between-field plant biodiversity have a positive effect on the provision of ecosystem services. For instance, it can reduce inputs and give higher and more stable plant production. It may even improve farmers’ management conditions. However, our work revealed two gaps in our scientific knowledge. Only 3 scientific articles connected ecosystem services with plant biodiversity at the farm scale or between fields, while stakeholders did so for 43 % of the services they mentioned. Similarly, management services concerned about one-third of the services mentioned by stakeholders but were addressed in only 3 scientific articles. Stakeholders’ expertise can thus help us to prioritize research options in order to simultaneously fill scientific gaps and produce knowledge relevant to practice. [M. Lugnot & G. Martin (2013). Biodiversity provides ecosystem services: scientific results versus stakeholders’ knowledge. Regional Environmental Change, on-line 03 March 2013. Photo: ENDURE.] Comment

Controlling weeds with biodiversity

David Low / WeedsNews4364 / March 27, 2013 / 7:54:38 PM EST / 0 Comments
Abstract: Farmland biodiversity and its associated ecosystem services are affected by agricultural activities at multiple spatial scales. Among these services, the regulation of weeds by invertebrate seed predators has received much attention recently but little is known about the relative effect of local management and landscape context of fields on this process. We monitored seed predation on four common weed species and carabid communities in 28 winter-cereals fields during five consecutive weeks in spring 2010. These fields were situated in contrasted landscape contexts and varied in terms of intensity of pesticide treatments and soil tillage regimes. Weed seed predation was strongly and positively related to the Shannon diversity of (strictly) granivorous carabids and to the activity–density of omnivorous carabids but negatively to the richness of omnivorous carabids. Weed seed predation and granivore diversity were positively related to landscape diversity and the proportion cover of temporary grassland within a 1000 m radius around focal fields and were negatively affected by the intensity of local pesticide treatments. No-till systems sheltered higher diversity of granivorous carabids but did not show higher seed predation rates. We showed that landscape composition factors had a higher relative influence than local practices factors on weed seed predation service. Consequently, weed management strategies should not only consider the management of single fields but also the surrounding landscape to preserve carabid biodiversity and enhance weed seed predation service. [Aude Trichard, Audrey Alignier, Luc Biju-Duval & Sandrine Petit (2013). The relative effects of local management and landscape context on weed seed predation and carabid functional groups. Basic and Applied Ecology, online 1 March 2013] [Photo: The granivore, Harpalus rufipes, feeding on weed seed at the soil surface © INRA] Comment

Weeds can be used as quality forage

David Low / WeedsNews4360 / March 26, 2013 / 7:59:36 PM EST / 0 Comments
[On Pasture 19 March 2013 By Kathy Voth] -- Forage quantity, quality and cost limit how much livestock a producer can raise, and how much money he/she makes doing it. Our emphasis on pasture grasses has led to decades of research to improve grass varieties, and farmers and ranchers have sprayed, burned, mowed, seeded, and invested in the necessary equipment for all this in an effort to increase the quantity and quality of pastures. There is an alternative. By understanding a little more about what’s growing in our pastures, and how animals choose what to eat, we could reduce expenses and increase the numbers of cattle we can produce. By turning weeds into forage, producers could potentially raise more cattle, and spend less money doing it .... Economist John Morley found that, based on average pasture weed populations, if a producer’s cattle ate just 70% of the weeds available, that producer would have about 43% more forage. This is just an average and your percentage will be different based on your past weed management practices .... Weeds are also high quality forage, maintaining much higher levels of protein through the growing season than typical pasture grasses. Because they have a higher leaf to stem ratio than grasses, they generally have better digestibility numbers as well. A maintenance ration for cattle requires 8% protein, so when grasses dry in mid-summer and drop below 8%, weeds can provide the protein cattle need to maintain, or even to gain weight. Higher levels of protein in weeds can also provide the nutrients rumen microbes need to process lower quality forages, so we can take advantage of forage that might not otherwise have been useful. Comment

Maryland introduces pesticide reporting bill

David Low / WeedsNews4358 / March 25, 2013 / 9:05:08 PM EST / 0 Comments
[PAN 21 March 2013 by Kristin Schafer] -- Access to information can be a powerful thing. The pesticide industry understands this, which must be why they're fighting tooth and nail to block — for the third time — a commonsense law that would require pesticide use reporting in Maryland. But the people of Maryland are fighting back. A strong coalition has formed around the "Smart on Pesticides" law, which is being considered right now by state legislators. They're making the case that children, communities and the precious Chesapeake Bay will all be better protected if decisionmakers know what pesticides are being used and where. A very simple — and very smart — idea. The Pesticide Reporting and Information Act (SB 675 and HB 775) would require pesticide users and sellers to make information that they are already required to maintain publicly available. This data would help public health and environmental experts identify "hot spots" and determine which pesticides are putting children’s health and waterways at risk. Biologists say, for example, that such data would help them address the growing problem of intersex fish in the bay. In some locations between 50-100% of the male bass examined are producing eggs rather than sperm. The scientists told Washington Postreporters that "lack of data on pesticides running into the bay" is keeping them from understanding and effectively addressing the problem. Comment

Optimising sustainable weed control options for wheat producers

David Low / WeedsNews4354 / March 25, 2013 / 9:46:54 AM EST / 0 Comments
[SARE 01 Feb 2013] – North Carolina organic wheat producers who face challenges in controlling stubborn weeds, specifically Italian ryegrass, may soon be able to choose from varieties that suppress those weed populations. North Carolina State University graduate student Margaret Worthington is studying 60 soft red winter wheat cultivars from public and private breeding programs for morphological characteristics and allelopathic traits that would help the wheat plants out-compete Italian ryegrass. “The goal of the project is identify wheat varieties that can out-perform Italian ryegrass in the field while not compromising yields, so that organic and conventional wheat growers have options available to them to control weeds that don’t involve chemical applications,” said Worthington. “Through this work, we can develop improved breeding protocols that will enable public sector wheat breeders across the Southeast to select for lines with enhanced allelopathy and morphological traits conferring weed suppressive ability. Comment

Human health impacts of exposure to herbicides and pesticides: a review

David Low / WeedsNews4346 / March 21, 2013 / 10:51:43 AM EST / 0 Comments
Summary: The objectives of this paper are to provide a summary scientific review of peer‐reviewed literature on the human health impacts of exposure to pesticides, especially those that may be impacting Australia’s Great Barrier Reef; and to briefly review key international concerns and emerging approaches to pesticide issues. Evidence is provided of the increased risk of some adverse health effects from exposure to pesticides. There is evidence that a number of the pesticides found in the Great Barrier Reef waters and in waterways discharging into the area may cause cancer (e.g. atrazine, 2,4‐D,diuron, simazine), neurological conditions (chlorpyrifos), birth defects (atrazine, 2,4‐D, diuron, endosulfan, MCPA), reduced foetal growth (atrazine, chlorpyrifos, 2,4‐D,metolachlor), and metabolic problems leading to obesity and diabetes (chlorpyrifos). Foetal and early childhood exposures to pesticides are a key concern, with considerable evidence of links between such exposures to a wide variety of pesticides and a range of childhood cancers, especially brain cancer and leukaemia. Prenatal exposure, particularly to organophosphate insecticides, is strongly linked with a range of developmental, cognitive and behaviour deficits, that can result in lasting adverse effects on the brain and leading towhat has been described as a “silent pandemic” of developmental neurotoxicity. Prenatal exposure is also strongly linked with a range of birth defects. More …

Herbicides pollute commercial compost

David Low / WeedsNews4343 / March 20, 2013 / 4:26:49 PM EST / 0 Comments
[Planet Natural 07 Dec 2012 by Bill Kohlhaase] -- When the State of California required Los Angeles to reduce its landfill waste, the city had the perfect solution. Compost! A large percentage of what went into the dumps came from lawns, gardens and parks. By collecting green waste, composting it and marketing it back to the public, the City not only reduced its waste by half, it made money to boot. The commercial compost was sold by the yard to large growers and landscape services as well as in attractive bags at select home, garden and grocery stores. The program more than paid for itself. Win-win! Then the reports started coming in. Growers of tomatoes, peas and other vegetables noticed they were losing crops. Sunflowers and daisies died. The culprit was found to be Clopyralid, a widely-used dandelion herbicide, found to be present in the City-manufactured compost. Suddenly compost programs in Los Angeles, Spokane and other parts of the country came to a halt as the “contaminated compost” scandal spread. Clopyralid isn’t the only contaminant that buyers of commercial compost have had to worry about. There’s a wide array of herbicides, pesticides, heavy metals and other chemicals as well as bacterial pathogens that can make their way into commercial compost. Compounding the problem are persistent toxins from sprays used on forests (forest products make up a large share of commercial compost). The addition of sewage sediments and sludge — once freely labeled as such, now more stealthily named — as well as other waste water by-products harboring everything from heavy metals to prescription drugs show up in compost. As the often-heard saying goes, garbage in, garbage out. Comment

Study finds it's cheaper to prevent agricultural pollution

David Low / WeedsNews4340 / March 19, 2013 / 12:11:32 PM EST / 0 Comments
Abstract: Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs) have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMPs for nonpoint source pollution control include cover crops, prescribed grazing, livestock access control, contour farming, nutrient management, and conservation buffers. The selected BMPs for stormwater management are rain gardens, roadside ditch retrofitting, and detention basin retrofitting. Cost-effectiveness is measured by the reduction in pollutant loads in total suspended solids and total phosphorus relative to the total costs of implementing the selected BMPs. The pollution load reductions for these BMPs are based on the total pollutant loads in the watershed simulated by the Soil and Water Assessment Tool and achievable pollutant reduction rates. The total implementation cost includes BMP installation and maintenance costs. The assessment results indicate that the BMPs for the nonpoint source pollution control are generally much more cost-effective in improving water quality than the BMPs for stormwater management. [Qiu, Zeyuan (2013). Comparative assessment of stormwater and nonpoint source pollution best management practices in suburban watershed management. Water, 5(1), 280-291.] [Photo credit: USDA] Comment

Fungicide use surging, largely unmonitored

David Low / WeedsNews4338 / March 19, 2013 / 11:01:56 AM EST / 0 Comments
[Environmental Health News 22 Feb. 2013 by Brett Israel] -- With an estimated $8-billion global market in 2005, industry experts now predict $21 billionworth of fungicides will be sold annually by 2017. Spraying of soybean crops quadrupled between 2002 and 2006 in an effort to fight Asian Soybean Rust, according to the latest data available from the U.S. Department of Agriculture. Fungicides were routinely applied on up to 30 percent of USA's 220 million acres of corn, soybean and wheat, according to a 2009 estimate. University of Kentucky plant pathologist Paul Vincelli estimates that 10 to 15 percent of all U.S. crops are treated with fungicide. "It's concerning," said Jason Belden, an environmental toxicologist at Oklahoma State University. "We have limited toxicological data for a lot of these compounds." Fungicides are contaminating the majority of water bodies tested in states where there is heavy use, such as in Maine, Idaho and Wisconsin. Some are known to be highly toxic to aquatic creatures, but little is known about whether they are actually harming frogs or other animals in the environment. The potential threats to people are unknown, with new research on lab mice linking them to obesity. Farmers have historically sprayed fungicides to stop disease. But over the past decade, in an effort to squeeze extra bushels from their crops, they have been spraying more kinds of fungicides on more acres. Farmers around USA are doing the same, causing an unprecedented surge in fungicide use. But as widespread contamination of waterways near these farms emerges, experts warn that there is inadequate environmental monitoring and information on the chemicals' safety. "It's concerning," said Jason Belden, an environmental toxicologist at Oklahoma State University. "We have limited toxicological data for a lot of these compounds." Comment

Economic and policy issues of U.S agricultural pesticide use trends

David Low / WeedsNews4333 / March 14, 2013 / 4:42:59 PM EST / 0 Comments
Summary: Current pesticide policy focuses on reducing dietary and other risks to meet safety standards, rather than weighing risks and benefits, and mitigating impacts by finding “safer” alternatives. This paper discusses U.S. agricultural pesticide use trends from 1964 to 2010 based on estimates developed from USDA surveys, and the influence of economic factors, agricultural policy, and pesticide regulation on aggregate quantities and mix of pesticides used. Synthetic organic pesticide use grew dramatically from the 1960's to the early 1980's, as farmers treated more and more acreage. Use then stabilized, with herbicides applied to about 95 percent of corn, cotton, and soybean acres, annually. Subsequently, major factors affecting trends were: 1) changes in crop acreage and other economic factors, 2) use of new pesticides that reduced per-acre application rates and/or met more rigorous health and environmental standards, and 3) adoption of genetically engineered insect-resistant and herbicide-tolerant crops. The use of pesticides and other control practices responded to economic factors such as input and output markets and agricultural policies. Changing societal values toward pesticide risks and benefits profoundly affected pesticide policy, influencing the pesticides available for use, but only indirectly affecting aggregate quantities used. While the current pesticide regulatory process might have economic inefficiencies, it might be consistent with policy preferences held by much of the public -- to reduce pesticide hazards rather than minimize regulatory costs. [Craig D. Osteen & Jorge Fernandez-Cornejo (2013). Economic and policy issues of U.S agricultural pesticide use trends. Pest Management Science, online 08 March 2013] Comment

Microbial agents for control of aquatic weeds and their role in integrated management

David Low / WeedsNews4332 / March 12, 2013 / 9:27:39 PM EST / 0 Comments
Abstract: Aquatic ecosystems throughout the world are threatened by the presence of invasive aquatic plants, both floating and submerged. Some of the aquatic species, such as water hyacinth (Eichhornia crassipes [Mart.] Solms), alligator weed, Alternanthera philoxeroides (Mart.), giant salvinia, Salvinia molesta D.S. Mitchell and water lettuce (Pistia stratiotes L.), Griseb. despite being relatively minor problems in their native range, have become major invaders of aquatic habitats in other parts of the world after having escaped from their natural enemies. Unchecked growth of aquatic vegetation is generally undesirable and reduces the value of the water resource. Despite adopting all control options including manual, mechanical, chemical and classical biological, the problem persists. The current weed management is oriented towards finding approaches that are effective in controlling the weed and reducing environmental contamination from herbicides. Plant pathogens have been gaining increasing attention and interest among those concerned with developing environmentally friendly, effective and compatible approaches for integrated management of the noxious weeds. This paper discusses some of the major microbial agents associated with aquatic weeds and their increasing role in integrated weed management. [Ray, P. & Hill, M. P. (2013). Microbial agents for control of aquatic weeds and their role in integrated management. CAB Reviews, 8, 014, 1-9] Comment

Global organic food and beverage sales approach $US63 billion

David Low / WeedsNews4324 / March 8, 2013 / 12:35:11 PM EST / 0 Comments
[IFOAM 13 Feb 2013] -- The Research Institute of Organic Agriculture (FiBL) and the International Federation of Organic Agriculture Movements (IFOAM) reports that organic food and beverage sales have now top 60 billion US dollars for the first t time. Nearly two million farmers in 162 countries now grow organically on more than 37 million hectares of agricultural land worldwide. The global market for organic food reached 62.9 billion US dollars in 2011, which is 4 billion more than reported for 2010. "200.000 new organic farmers, this is good news for the environment and for the social and economic development of rural areas", says IFOAM president and Australian organic farmer Andre Leu. In fact, the results of the latest annual global survey on organic agriculture conducted by FiBL and IFOAM show evidence of continued growth. Past investments have clearly paid off and three new initiatives are now paving the way for investments in future growth and expansion. These figures show that in countries where organic agriculture is institutionally well embedded, there is constant market growth and expansion of the area under organic management. This is impressively shown in the case of Europe, where many countries provide a wide range of support measures such as direct payments, advisory services, relevant research and marketing measures. This underpins the importance of National Action Plan development, as promoted by FiBL and IFOAM. Comment

2,4-D found to be potential cancer initiator

David Low / WeedsNews4323 / March 8, 2013 / 12:33:02 PM EST / 0 Comments
Abstract: We studied the eco-toxic and carcinogenic effects of a commonly used 2,4-D acid iso-octylester herbicide on rat liver and pancreas. The rats in Group 1 were fed a standard feed and the rats in Group 2 were fed with standard feed to which was added 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks. Azaserine, 30 mg/kg/body weight, was injected into rats of Groups 3 and 4 to investigate the effects of 2,4-D acid iso-octylester on the development of neoplasms. After feeding the rats with neoplasms in Group 4 with food including 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks, an autopsy was carried out on all animals. We found that 2,4-D acid iso-octylester caused the formation of atypical cell foci (ACF) in the pancreata and livers of rats. ACF that were formed experimentally by exposure to azaserine had increased diameter, volume and number of atypical cell foci/mm2 and mm3after exposure to 2,4-D acid iso-octylester. Our observations indicated that this herbicide potentially is a cancer initiator. [C Ozdemir & H Oztas (2013). Assessing eco-toxicological effects of industrial 2,4-D acid iso-octylester herbicide on rat pancreas and liver. Biotechnic & Histochemistry, online on February 11, 2013: doi:10.3109/10520295.2012.758312] Comment

GMO cultivation banned in Washington State county

David Low / WeedsNews4322 / March 8, 2013 / 12:24:07 PM EST / 0 Comments
[AllAboutFeed 1 March 2013] -- In San Juan County, Washing State, the population of 16,000 voted in favour of banning the “propagation, cultivation or growing of genetically modified organisms” in the county. The initiative 2012-4 was won by a 1.5 to 1 majority. According to the Washington State Department of Agriculture, the county has 291 farms producing US$4 million in crops annually. The first violation is a Class 1 civil infraction carrying a $250 penalty plus statutory assessments. The second violation is a criminal misdemeanor punishable by a fine of up to $1,000, 90 days in jail, or both. A third or subsequent violation is a gross misdemeanor punishable by a fine of up to $5,000, 365 days in jail, or both. According to the initiative, criminal charges will be brought only when civil remedies have failed to ensure compliance. The initiative does allow for the growth of hybrid organisms and GMOs to be grown by health-care providers and researchers in secure environments. It will not affect GMO products sold in local grocery stores. Comment

Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

David Low / WeedsNews4320 / March 8, 2013 / 11:34:55 AM EST / 0 Comments
Abstract: The allelopathic potential of rye (Secale cereale L.) is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a cover crop to control summer weeds in a following maize crop. Significant differences in benzoxazinoid content were detected between rye cultivars. In controlled environments, rye mulches significantly reduced germination of some broadleaf weeds. Germination and seedling growth of Amaranthus retroflexus and Portulaca oleracea were particularly affected by the application of rye mulches, while Chenopodium album was hardly influenced and Abutilon theophrasti was advantaged by the presence of the mulch. With reference to the influence of agronomic factors on the production of benzoxazinoids, nitrogen fertilization increased the content of allelochemicals, although proportionally less than dry matter. The field trial established on no-till maize confirmed the significant weed suppressiveness of rye mulch, both for grass and broadleaf weeds. A significant positive interaction between N fertilization and no-tillage resulting in the suppression of broadleaf weeds was observed. The different behavior of the weeds in the presence of allelochemicals was explained in terms of differential uptake and translocation capabilities. The four summer weeds tested were able to grow in the presence of low amounts of benzoxazolin-2(3H)-one (BOA), between 0.3 and 20 μmol g−1 fresh weight. Although there were considerable differences in their sensitivity to higher BOA concentrations, P. oleracea, A. retroflexus, and Ch. album represented a group of species with a consistent absorption capability. The insensitivity of A. theophrasti to BOA was due to reduced accumulation in seedlings. Overall, results confirm that the use of a rye cover crop in a suitable crop rotation represents a sustainable weed management practice permitting a reduction in the amount of herbicides used in agroecosystems, thus limiting the environmental risks of intensive agriculture. [Vincenzo Tabaglio, Adriano Marocco & Margot Schulz (2013). Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems. Italian Journal of Agronomy, 8(5), 35-40.] Comment

Phytoremediation of atrazine-contaminated soil using Zea mays (maize)

David Low / WeedsNews4318 / March 7, 2013 / 2:20:30 PM EST / 0 Comments
Abstract: Greenhouse experiments were carried out to determine the potential capability of maize plants to remediate atrazine-contaminated soil. The potted sandy loam soil was treated with atrazine (Gesaprim 90%WG) at 0.5 and 1.0 ppm then was planted immediately with maize. After 15, 30, 45 and 60 days from sowing, maize plants were cut and discarded. Wheat seeds were sown in treated soil to determine atrazine residues. Untreated soil and soil unplanted with maize served as controls. Seven days after sowing, the shoot and root lengths of wheat seedlings were measured. The results indicated that shoot and root lengths of wheat in the treated-soil previously planted with maize were taller than the treated-unplanted soil. Persistence percentage of atrazine in the treated soil was estimated by determining the residues of atrazine by Gas Liquid Chromatography (GLC). The obtained data showed that residues of atrazine were less in soil planted with maize compared with unplanted soil. Considerable concentrations of atrazine, i.e., 0.99 ppm and 0.14 ppm were detected in sterilized unplanted or planted soils with maize after 30 days of sowing, respectively. While these values, were 0.38 ppm and 0.09 ppm in sterilized unplanted or planted soil with maize after 60 days of sowing, respectively. This study demonstrated that residues of atrazine were reduced in faster rate in contaminated soil planted with Zea mays than the unplanted soil. Results indicated that Z. mays was useful for phytoremediation of soils contaminated with atrazine. [S.I. Ibrahim, , M.F. Abdel Lateef, H.M.S. Khalifa & A.E. Abdel Monem (2013). Phytoremediation of atrazine-contaminated soil using Zea mays (maize). Annals of Agricultural Sciences, online 27 February 2013] Comment

Biological utilities of Parthenium hysterophorus

David Low / WeedsNews4316 / March 7, 2013 / 2:02:49 PM EST / 0 Comments
Abstract: Parthenium hysterophorus L. (Asteraceae) is a serious weed of pastures, wasteland and agricultural fields in world. Various problems are posed by the weed to human health, agriculture, live stock production and biodiversity. It is used as folk remedy against various afflictions. The review discusses several prominent biological utilities of P. hysterophorus as it contains several important chemical constituents mainly histamine, saponin, glucosides and triterpene (sesquiterpene) and can be of use for the purpose of biocontrol of various pathogens, for its medicinal utility and even for the purpose of food. [Veena B. Kushwaha & Shivani Maury (2012). Biological utilities of Parthenium hysterophorus. Journal of Applied and Natural Science, 4 (1), 137-143.] Comment

A meta-analysis of the effects of pesticides and fertilizers on survival and growth of amphibians

David Low / WeedsNews4308 / March 1, 2013 / 1:15:01 PM EST / 0 Comments
Abstract: The input of agrochemicals has contributed to alteration of community composition in managed and associated natural systems, including amphibian biodiversity. Pesticides and fertilizers negatively affect many amphibian species and can cause mortality and sublethal effects, such as reduced growth and increased susceptibility to disease. However, the effect of pesticides and fertilizers varies among amphibian species. We used meta-analytic techniques to quantify the lethal and sublethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date and produce generalized conclusions. We found that pesticides and fertilizers had a negative effect on survival of − 0.9027 and growth of − 0.0737 across all reported amphibian species. We also observed differences between chemical classes in their impact on amphibians: inorganic fertilizers, organophosphates, chloropyridinyl, phosphonoglycines, carbamates, and triazines negatively affected amphibian survival, while organophosphates and phosphonoglycines negatively affected amphibian growth. Our results suggest that pesticides and fertilizers are an important stressor for amphibians in agriculturally dominated systems. Furthermore, certain chemical classes are more likely to harm amphibians. Best management practices in agroecosystems should incorporate amphibian species-specific response to agrochemicals as well as life stage dependent susceptibility to best conserve amphibian biodiversity in these landscapes. [Nick J. Baker, Betsy A. Bancroft & Tiffany S. Garcia (2013). A meta-analysis of the effects of pesticides and fertilizers on survival and growth of amphibians. Science of The Total Environment, 449(1), 150–156] [Photo: Amphibian populations are declining worldwide - Science Daily.] Comment

Challenging a herbicide-based bioeconomy: The dynamics of collective action in Argentina

Zheljana Peric / WeedsNews4306 / March 1, 2013 / 1:03:26 PM EST / 0 Comments
Abstract: This paper analyzes the local bottom-up dynamics of challenging the growth of a bioeconomy in Argentina. In the last decade, growing controversies and conflict have arisen in the region regarding the adoption of genetically modified crops and the growing use of glyphosate-based herbicides. Even if the industry and the World Health Organization claim that glyphosate is a product of low-toxicity, an increasing body of scientific research shows severe health problems for villagers and farmers. In Argentina, many peasants, neighbors, environmental activists, as well as rural physicians, scientists, agronomic engineers and lawyers have asked for a ban or strict limits on the use of glyphosate-based herbicides. Using a case study, I focus on collective action between 1996 and 2011 aimed at changing “science-based regulations” for the commercialization and use of agrochemicals. I demonstrate that by implementing diverse and innovative collective strategies as well as promoting the creation of new scientific data, affected populations can achieve some degree of influence on decisions regarding risk. Even if social and scientific disagreements over regulatory frameworks for biotechnology in Latin America have been acknowledged in the literature, regulatory science has rarely been thought of as a field of social struggle where social movements can participate and promote change. This is an important contribution to the emerging field of studies focused on political collective action and social movements within science and technology. [Florencia Arancibia (2013). Challenging the bioeconomy: The dynamics of collective action in Argentina. Technology in Society, online 18 February 2013] Comment

Are environmental transitions more prone to biological invasions?

David Low / WeedsNews4303 / February 28, 2013 / 10:31:20 PM EST / 0 Comments
Abstract: The aim was examine whether at a subcontinental-scale ecotonal areas of transition between vegetation communities are at higher risk of plant invasion. Location: South Africa and Lesotho. Methods: Using plant data on native and established alien species in South Africa, we examined the relationship between plant richness (native and alien) in each grid cell (quarter-degree resolution) in the study area and the distance of the grid cell to the nearest ecotone between vegetation communities. We used a residual analysis to estimate each grid cell's relative invasibility (i.e. susceptibility to invasion) relative to its ecotone distance. We further explored the relative importance of ecotones in relation to large-scale environmental variation, and the importance of ecotonal spatial heterogeneity, in structuring alien species richness patterns. Results: Both alien and native richness patterns become higher with declining distance to ecotones, suggesting that transitional environments are more susceptible to invasion than areas located farther away; however, levels of invasibility vary across South Africa. The negative relationship between ecotone distance and alien species richness remained negative and significant for the whole of South Africa, grassland and Nama-Karoo, after controlling for environmental variables. Several sources of environmental heterogeneity, which were shown here to be associated with ecotones, were also found to be important determinants of alien species richness. Main conclusions: While most of the current conservation efforts at the regional and global scales are currently directed to distinct ecosystems, our results suggest that much more effort should be directed to the transitions between them, which are small in size and have high native richness, but are also under greater threat from invasive alien species. Understanding how alien species richness and invasibility change across transitions and sharp gradients, where environmental heterogeneity is high, is important for ongoing conservation planning in a biogeographical context. [van Rensburg, B. J., Hugo, S., Levin, N., Kark, S. (2013). Are environmental transitions more prone to biological invasions? Diversity and Distributions, 19: 341–351. doi: 10.1111/ddi.12026] Comment

Chemical composition, physico-chemical properties, antifungal and herbicidal activities of Pinus halepensis Miller essential oils

David Low / WeedsNews4302 / February 28, 2013 / 10:02:23 PM EST / 0 Comments
Abstract: The chemical composition, physico-chemical properties, and antifungal and herbicidal activities of essential oils obtained by hydrodistillation from needles, stems and cones of Pinus halepensis Miller were investigated. The chemical composition analysed by GC and GC/MS varied significantly among organs. Among the 67 identified components, α-pinene (63% and 51.7%, respectively, in stems and cones) and (Z)-caryophyllene (33.9% in needles) were found to be the major ones. Moreover, it was found that chemical composition of essential oils extracted from different organs of P. halepensis Miller growing in Tunisia showed noteworthy differences with the same species cultivated in Algeria, Morocco, Greece and Italy based on a comparison with published results. In addition, the physico-chemical properties of essential oils from different organs of P. halepensis were analysed. The analysis of the refraction index, density and acid index of different oil samples showed a weak variability among organs. The in vitro antifungal activity of the essential oil samples evaluated against 10 cultivated crop fungi was found to be low, probably due to the low level of oxygenated compounds in P. halepensis oils. In contrast, the herbicidal activity investigated towards three common weeds in Tunisian cereal crops was very strong and seed germination was inhibited at 2 μl ml− 1. Thus, P. halepensisessential oil appears to have more value as a bioherbicide than as a biofungicide. [Ismail Amri, Lamia Hamrouni, Mohsen Hanana, Samia Gargouri, Tarek Fezzani & Bassem Jamoussi (2013). Chemical composition, physico-chemical properties, antifungal and herbicidal activities of Pinus halepensis Miller essential oils. Biological Agriculture & Horticulture: An International Journal for Sustainable Production Systems, online 13 Feb 2013.]

Invasive species cost Europe €12 billion each year

David Low / WeedsNews4293 / February 28, 2013 / 4:45:25 PM EST / 0 Comments
[EEA 21 February 2013] The European Environment Agency (EEA) has released two reports on invasive species. The first, titled "The impacts of invasive alien species in Europe," discusses the effects and spread of some invasive species. Weed species examined include Japanese knotweed (Fallopia japonica), ice plant (Carpobrotus edulis), pontic rhododendron (Rhododendron ponticum) and water hyacinth (Eichhornia crassipes). The second, titled "Invasive alien species indicators in Europe," looks at the methodology for collecting the data. The first report notes, through 28 dedicated species accounts, that invasive species are largely introduced for horticulture, but also for other reasons including farming, hunting and fishing, or as pets. Trade and tourism can compound the effects of their diffusion as well as climate change, which allows for some species to spread more easily. The report on indicators also highlights the high economic costs of invasive alien species. It estimates that they cost Europe around €12 billion per year, by damaging crops or fouling water filtration plants and water cooling reservoirs of power plants. [Photo: Pontic rhododendron is the most important host for Sudden Oak Death that threatens trees, woodland ecosystems and other habitats in Europe.] Comment

The impacts of traditional and novel herbicide application methods on target plants, non-target plants and production in intensive grasslands

David Low / WeedsNews4291 / February 23, 2013 / 10:16:07 PM EST / 0 Comments
Abstract: Herbicides contribute significantly to agricultural intensification, but some negatively impact non-target organisms. Much research has focused on reducing herbicide use through technological improvements in application and herbicide selectivity, but impacts on non-target organisms are less well understood. Using experimental plots in silage systems, we investigated impacts of herbicides (both narrow spectrum targeting broad-leaved plants and selective and non-selective broad spectrum) applied using traditional techniques (blanket- and manual spot-spraying) and a novel application technique (automated spot-spraying) on non-target plant richness/diversity, target weed presence (Rumex species) and production (DM yield). All herbicides reduced non-target plant richness/diversity and sometimes target weeds (when applied using traditional methods). Automated spot-spraying had fewer negative effects on non-target organisms, but did not reduce target weeds. No differences in production levels among treatments were observed. The automated spot-spraying technique requires further research and development. Our results indicate that 20–30% weed cover does not significantly alter production and so, as herbicides are expensive, their effects on non-target organisms and the environment can be more significant than their benefits to production. We advocate more research into the relationships between weed infestation and production in grasslands, so that the propensity to overuse herbicides is reduced. [Power EF, Kelly DL & Stout JC. (2013). The impacts of traditional and novel herbicide application methods on target plants, non-target plants and production in intensive grasslands. Weed Research, online 15 Feb 2013.] Comment

U.S. report urges deeper look into breast cancer's links to herbicides

David Low / WeedsNews4285 / February 21, 2013 / 11:46:45 PM EST / 0 Comments
[The Center for Public Integrity 12 Feb 2013 by Jim Morris] -- A new federal advisory panel reportmakes a forceful case for more research into environmental causes of breast cancer, which was diagnosed in 227,000 women, killed 40,000 and cost more than $17 billion to treat in the United States last year. Compiled by the congressionally mandated Interagency Breast Cancer and Environmental Research Coordinating Committee, the report notes that most cases of breast cancer “occur in people with no family history,” suggesting that “environmental factors — broadly defined — must play a major role in the etiology of the disease.” Yet only a fraction of US Federal research funding has gone toward examining links between breast cancer and ubiquitous chemicals such as the plastic hardening agent bisphenol A; the herbicide atrazine; and dioxin, a byproduct of plastics manufacturing and burning, says the report, prepared for Health and Human Services Secretary Kathleen Sebelius and released today. “Prevention needs to be as important as other investments that are made in screening, treatment and access to care,” Jeanne Rizzo, co-chair of the committee and president of the San Francisco-based Breast Cancer Fund, said in an interview. “There really is a problem, and until we address it we’re going to continue to have a quarter of a million new cases every year. Comment

Cover crops shown to successfully suppress weeds

David Low / WeedsNews4284 / February 21, 2013 / 11:44:09 PM EST / 0 Comments
[USDA 04 Feb 2013 by Ann Perry] -- Farmers can fine-tune their use of cover crops to help manage costs and maximize benefits in commercial organic production systems, according to U.S. Department of Agriculture (USDA) scientists. Production expenses for high-value organic crops like lettuce and broccoli can exceed $7,000 per acre, so producers often try to streamline costs with an annual two- to three-crop rotation. Agricultural Research Service (ARS) horticulturalist Eric Brennandesigned a long-term investigation that examined several different cover cropping strategies for an annual organic lettuce-broccoli production system. ARS is USDA's chief intramural scientific research agency, and this work supports the USDA priority of promoting international food security. The researcher selected three winter cover crops often grown in the Salinas, Calif., area—rye, mustard, and a legume-rye mix—and planted each cover crop using either a typical seeding rate or a seeding rate that was three times higher. Seeding rates can influence a cover crop's ability to smother weeds. During lettuce and broccoli production, Brennan ensured all systems received the same fertilizer and irrigation inputs and pest management. The harvest and sale of the crops, which met all USDA organic standards, were conducted by a commercial harvester. Comment

Report exposes impact of Monsanto practices on U.S. farmers

David Low / WeedsNews4282 / February 21, 2013 / 11:08:14 PM EST / 0 Comments
[CFS Washington, D.C. – February 12, 2013] -- A new report released by the Center for Food Safety investigates how the current seed patent regime has led to a radical shift to consolidation and control of global seed supply and how these patents have enabled corporations, such as herbicide manufacturer Monsanto, to sue U.S. farmers for alleged seed patent infringements. Seed Giants vs. U.S. Farmers also examines broader socio-economic consequences of the present patent system including links to loss of seed innovation, rising seed prices, reduction of independent scientific inquiry, and environmental issues. While agrichemical corporations also claim that their patented seeds are leading to environmental improvements, the report notes that upward of 26 percent more chemicals per acre were used on GE crops than on non-GE crops, according to USDA data. Further, in response to an epidemic of weed resistance to glyphosate, the primary herbicide used on GE crops, Dow AgroSciences is seeking USDA approval of “next generation” corn and soybeans resistant to 2,4-D, an active ingredient in Agent Orange. Monsanto is seeking approval for GE dicamba-resistant soybeans, corn, and cotton. Comment

A new method to evaluate the weed-suppressing effect of mulches: a comparison between spruce bark and cocoa husk mulches

David Low / WeedsNews4281 / February 21, 2013 / 10:45:54 PM EST / 0 Comments
Summary: To suppress weeds in an apple (Malus sp.) orchard, we placed spruce (Picea spp.) bark mulch and cocoa (Theobroma cacao) husk mulch for 3 months in thicknesses of 0, 2.5, 5, 10 and 15 cm. To assess the development of weed cover, an innovative use of log-logistic dose–response models was applied, with mulch thickness as the independent variable. Weed cover was measured by non-destructive image analysis by estimating the relationship between the number of green pixels and the total number of pixels in each experimental plot. The thickness of mulch layer required to attain a 50 and 90% weed suppression (ED50 and ED90) differed significantly within and between mulch types. In all except one instance, the cocoa mulch was superior in suppressing weeds. This method was useful for the evaluation, but further research is needed to give a more general conclusion about the suppression ability of the two mulches under other climatic and growing conditions. [Arentoft BW, Ali A, Streibig JC & Andreasen C. (2013). A new method to evaluate the weed-suppressing effect of mulches: a comparison between spruce bark and cocoa husk mulches. Weed Research. online 15 Feb 2013] Comment

Soil salinity: A neglected factor in plant ecology and weed invasion

David Low / WeedsNews4280 / February 21, 2013 / 10:33:57 PM EST / 0 Comments
Abstract: This paper argues that soil salinity needs to be more broadly acknowledged as a driving factor in plant ecology—not only in the ecology of halophytes—in order to understand and make more accurate predictions for the impact of environmental change on biodiversity and vegetation patterns throughout the semi-arid world. It summarizes recent research on soil salinity and plant distributions in semi-arid environments throughout the world: there is empirical as well as experimental evidence that soil salinity, even at low levels, is an abiotic stress factor that influences vegetation patterns and diversification. Lines of evidence demonstrating salinity's potential influence as a selective agent in East Africa and North America are presented. The paper then synthesizes recent results from spatial ecology, plant and insect systematics and behavioral ecology, focusing on Australia, that support a role for salinity in evolutionary ecology of Acacia. On a shorter time scale, soil salinity may play a role in weed invasion and woody vegetation encroachment in Australia. [E.N. Bui (2013). Soil salinity: A neglected factor in plant ecology and biogeography. Journal of Arid Environments, Volume 92, pp 14–25] [Photo: Field observations in Queensland suggest that the woody weed Parkinsonia aculeata L. appears to colonize saline discharge areas where it forms monostands. Credit: ALA] Comment

Benefits of mixing grasses and legumes for herbage yield and nutritive value in Northern Europe and Canada

David Low / WeedsNews4278 / February 16, 2013 / 11:09:10 PM EST / 0 Comments
Abstract: Increased biodiversity may improve ecosystem services, including herbage yield. A mixture experiment was carried out at five sites in Northern Europe and one in Canada to investigate whether mixtures of grasses and legumes would give higher herbage yield than monocultures. Resistance of the mixtures to weed invasion and nutritive value of the herbage were also investigated. The experimental layout followed a simplex design, where four species differing in specific functional traits, timothy (Phleum pratense L.), smooth meadow grass (Poa pratensis L.), red clover (Trifolium pratense L.) and white clover (Trifolium repens L.), were grown in monocultures and eleven different mixtures with systematically varying proportions of the four species. Positive diversity effects (DE) were observed, leading to greater herbage dry-matter (DM) yield in mixtures than expected from species sown in monocultures. For centroid mixtures, the DE generated on average an additional 32, 25 and 21% of the DM yield than would be expected from the monocultures in the first, second and third year respectively. On average, the mixtures were 9, 15 and 7% more productive than the most productive monoculture (transgressive overyielding) in the first, second and third year respectively. These benefits persisted over the three harvest years of the experiment and were consistent among most sites. This positive effect was not accompanied by a reduction in herbage digestibility and crude protein concentration that is usually observed with increased DM yield. Mixtures also reduced the invasion of weeds to <5% of herbage yield compared to monocultures (10–60% of herbage yield). [E. Sturludóttir, C. Brophy, G. Bélanger, A.-M. Gustavsson, M. Jørgensen, T. Lunnan & Á. Helgadóttir, (2013). Benefits of mixing grasses and legumes for herbage yield and nutritive value in Northern Europe and Canada. Grass and Forage Science, online 11 Feb 2013.] Comment

USA health concerns with herbicides puts the pressure on for more bans

David Low / WeedsNews4272 / February 13, 2013 / 10:49:05 PM EST / 0 Comments
[The Denver Post 10 Feb 2013 by Colleen O'Connor] -- Turf wars are flaring in Colorado, pitting people who prize pristine, weed-free lawns against those who want an organic, chemical-free lifestyle. The battle is so pitched that local lawn-and-garden pros fear that a Canadian-style ban on pesticides and herbicides looms ... The American Academy of Pediatrics added fuel to the fire last month with a policy statement that linked prenatal and early-childhood exposure to chemical pesticides with pediatric cancers, decreased cognitive function and behavioral problems. "It's one of the most contentious issues you can ever imagine," said Paul Tukey, founder of SafeLawns, an advocacy organization for natural lawn care. In Colorado, municipalities — including Boulder and Durango — have changed policies in response to residents worried about health consequences of synthetic pesticides. They're focused on eliminating chemical controls of weeds and insects in public parks and playgrounds, and proponents say such programs prove there are ways to both protect health and keep landscapes lovely. The University of Colorado doesn't use chemicals to treat turf in its open spaces or fields. Compost tea is used to fertilize, and weeds are hand-pulled. Outdoor-services manager Don Inglis said the change was made in response to students wondering "why we were using herbicides on campus when we are one of the leaders in the green industry, from the university standpoint." Comment

Review recommends more study of pesticides that cause cancer

David Low / WeedsNews4268 / February 13, 2013 / 10:15:32 PM EST / 0 Comments
Abstract: Pesticides constitute a diverse class of chemicals used for the protection of agricultural products. Several lines of evidence demonstrate that organochlorine and organophosphate pesticides can cause malignant transformation of cells in in vitro and in vivo models. In the current minireview a comprehensive summary of recent in vitro findings is presented along with data reported from human population studies, regarding the impact of pesticide exposure on activation or dysregulation of oncogenes and tumor suppressor genes. Substantial mechanistic work suggests that pesticides are capable of inducing mutations in oncogenes and increase their transcriptional expression in vitro, whereas human population studies indicate associations between pesticide exposure levels and mutation occurrence in cancer-related genes. Further work is required to fully explore the exact mechanisms by which pesticide exposure affects the integrity and normal function of oncogenes and tumor suppressor genes in human populations. [Elena Vakonaki, Vasilis P. Androutsopoulos, Jyrki Liesivuori, Aristidis M. Tsatsakis & Demetrios A. Spandido (2013). Pesticides and oncogenic modulation. Toxicology, online 24 Jan 2013] Comment

Navigating the “noxious” and “invasive” regulatory landscape: suggestions for improved regulation

David Low / WeedsNews4264 / February 13, 2013 / 8:49:51 PM EST / 0 Comments
Abstract: In the United States, only species listed on state or federal noxious weed lists are regulated. According to our analysis, these regulatory lists poorly represent invasive plants in unmanaged (i.e., nonagricultural) systems. To improve the representation of invasive plants on state regulatory lists, we recommend allocating listing authority to invasive species councils and provide guidance for the science-based reform of noxious weed lists. We also recommend commercial best practices to test for invasiveness prior to intentional introduction of new plant products. Finally, we introduce a negligence liability scheme to discourage the introduction of potential invaders. If adopted, our recommendations could benefit nonagricultural ecosystems and could have positive consequences for bioenergy producers and others in plant industry, who are under scrutiny for promoting potentially invasive species as energy crops. As the bioenergy industry gains momentum, a revised regulatory regime may alleviate the concerns regarding one potential negative consequence of novel plant introduction. [Lauren D. Quinn , Jacob N. Barney , James S. N. McCubbins & A. Bryan Endres (2013). Navigating the “noxious” and “invasive” regulatory landscape: suggestions for improved regulation. BioScience 63(2):124-131. dx.doi.org/10.1525/bio.2013.63.2.8] Disagree? Share your views on this article: Comment

Biodiversity helps protect nature against human impacts

David Low / WeedsNews4262 / February 11, 2013 / 9:42:14 PM EST / 0 Comments
[ScienceDaily Feb. 6, 2013] — "You don't know what you've got 'til it's collapsed." That's how University of Guelph integrative biologists might recast a line from an iconic folk tune for their new research paper warning about the perils of ecosystem breakdown. Their research, published February 6 as the cover story in Nature, suggests farmers and resource managers should not rely on seemingly stable but vulnerable single-crop monocultures. Instead they should encourage more kinds of plants in fields and woods as a buffer against sudden ecosystem disturbance. Based on a 10-year study, their paper also lends scientific weight to esthetic and moral arguments for maintaining species biodiversity. The study was written by Profs. Andrew MacDougall and Kevin McCann, graduate student Gabriel Gellner and Roy Turkington, a botany professor and member of the Biodiversity Research Centre at the University of British Columbia. Their research confirms that having lots of species in an area helps ecosystems avoid irreversible collapse after human disturbances such as climate change or pest invasion. "Species are more important than we think," said MacDougall. "We need to protect biodiversity."[Photo: Single-crop monoculture of corn.] Comment

Non-target effects of herbicides on soil nematode assemblages

David Low / WeedsNews4260 / February 10, 2013 / 9:38:55 PM EST / 0 Comments
Abstract: Herbicides are used extensively to control weeds. However, little is known about the non-target effects of herbicides on soil nematode assemblages. The objective of this study was to determine whether herbicides affect the abundance of nematodes in specific trophic groups. Meta-analysis was performed and the calculated effect size, lr, quantified the impact of herbicides on the abundance of total nematodes and five trophic groups (bacterivores, fungivores, plant-parasites, omnivores, and predators). Measurements of lr indicated that herbicides decreased abundance of both fungivores and predators; however, abundance of bacterivores, plant-parasites and omnivores increased. Overall, total nematode abundance tended to increase in response to herbicide application. The decrease of predator abundance suggests that herbicide application disturbs soil food webs. The increase of bacterivore and decrease of fungivore abundance suggest that bacterivores are more tolerant and both fungivores and predators more sensitive to herbicide applications. Herbicides also have non-target effects on omnivores, which may be due to the increased amount of food resources for omnivores after weed control. Additionally, the use of herbicides may result in a risk of an increase of plant-parasitic nematode abundance. [Jie Zhao, Deborah A. Neher, Shenglei Fu, Zhi'an Li & Kelin Wang (2013). Non-target effects of herbicides on soil nematode assemblages. Pest Management Science, online 05 Feb 2013] Comment

Targeting perennial vegetation in agricultural landscapes for enhancing ecosystem services

Zheljana Peric / WeedsNews4253 / February 8, 2013 / 1:48:35 PM EST / 0 Comments
Abstract: Over the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops—or perennialization—creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society. [H. Asbjornsen, V. Hernandez-Santana, M. Liebman, J. Bayala, J. Chen, M. Helmers, C.K. Ong & L.A. Schulte (2013). Targeting perennial vegetation in agricultural landscapes for enhancing ecosystem services. online 07 Feb 2013.] [Photo: An example of perennial grass strips with row crops - source] Comment

In standing up for industrial agriculture, are universities undercutting their own researchers?

David Low / WeedsNews4248 / February 7, 2013 / 12:01:59 PM EST / 0 Comments
[The Chronicle of Higher Education 01 Feb 2013 by Goldie Blumenstyk] -- In a case before the U.S. Supreme Court this month, advocates for academic researchers are urging the justices to reverse a patent-infringement decision that has given the Monsanto Company broad authority to restrict scientists’ study of genetically modified seeds. The decision, the advocates say, not only hurts farmers and fuels higher food prices; it also contributes to “the suffocation of independent scientific inquiry into transgenic crops.” Not surprisingly, the case has also drawn the attention of higher education’s research establishment—but it’s pulling for the other side. The friend-of-the-court brief that advocates for the academic scientists comes from two nonprofit organizations, the Center for Food Safety and Save Our Seeds. It describes professors at two universities who were forced to abandon their research on sugar beets grown from Monsanto’s patented Roundup Ready transgenic seeds, because the company insisted on the right to block publication of their findings. The brief also recalls a 2009 statement by 26 prominent university scientists who protested to the Environmental Protection Agency that because of the restricted access allowed under patents like the one in the Monsanto case, “no truly independent research can be legally conducted on many critical questions regarding the technology.” Some two dozen research universities and higher-education organizations, including the Association of Public and Land-Grant Universities and the Association of American Universities, filed another friend-of-the-court brief that sides with Monsanto. Many of them are active in the patenting and commercialization of research themselves, in some cases lucratively so. (One is North Dakota State University, whose researchers were thwarted in their sugar-beet research.) Comment

Silverleaf nightshade de-toxifies chromium contaminated soils.

Zheljana Peric / WeedsNews4242 / February 7, 2013 / 11:19:45 AM EST / 0 Comments
Abstract: The widespread use of chromium (Cr) has a deleterious impact on the environment. A number of pathways, both biotic and abiotic in character, determine the fate and speciation of Cr in soils. Chromium exists in two predominant species in the environment: trivalent [(Cr(III)] and hexavalent [Cr(VI)]. Of these two forms, Cr(III) is nontoxic and is strongly bound to soil particles, whereas Cr(VI) is more toxic and soluble and readily leaches into groundwater. The toxicity of Cr(VI) can be mitigated by reducing it to Cr(III) species. The authors compared results for the chicken manure biochar with acid-activated black carbon from a weedy species (Solanum elaeagnifolium Cav.). Results showed that the activated black carbon reduced all of the Cr(VI) to Cr(III) within 6 to 10 d, whereas the chicken manure biochar reduced between 198 and 219 mg kg−1 over the 14-d incubation; the estimated half-life for Cr(VI) reduction by biochar was between 10.7 and 11.4 d. Although biochar did not fully reduce Cr(VI) to Cr(III) within the timeframe of the study, results appear promising that both biochar and acid activated black carbons could play a role in reducing Cr(VI) in contaminated soils. Organic carbon sources, such as black carbon (BC) and biochar, were tested for their potential in reducing Cr(VI) in acidic and alkaline contaminated soils. An alkaline soil was selected to monitor the phytotoxicity of Cr(VI) in sunflower plant. In conclusion the showed that using BC resulted in greater reduction of Cr(VI) in soils compared with biochar. This is attributed to the differences in dissolved organic carbon and functional groups that provide electrons for the reduction of Cr(VI). When increasing levels of Cr were added to soils, both microbial respiration and plant growth decreased. The application of BC was more effective than biochar in increasing the microbial population and in mitigating the phytotoxicity of Cr(VI). The net benefit of BC emerged as an increase in plant biomass and a decrease in Cr concentration in plant tissue. Consequently, it was concluded that BC is a potential reducing amendment in mitigating Cr(VI) toxicity in soil and plants. [Choppala, G.K., N.S. Bolan, M. Megharaj, Z. Chen and R. Naidu. (2012). The influence of biochar and black carbon on reduction and bioavailability of chromate in soils. J. Environ. Qual. 41:1175–1184. doi:10.2134/jeq2011.0145] Comment

Scouts tackle invasive plants in Alaska

David Low / WeedsNews4239 / February 7, 2013 / 9:58:51 AM EST / 0 Comments
[Southeast Alalska Conservation Council 26 June 2012] -- WRANGELL, AK – Members of Wrangell’s Scout Troop 40 joined forces with the Southeast Alaska Conservation Council (SEACC), the Sitka Conservation Society (SCS) the United States Forest Service and local Wrangell volunteers to conduct a number of Wilderness stewardship activities on the Stikine River. The outing, funded in part by a grant through the National Forest Foundation, focused on managing invasive weeds near Twin Lakes and was part of a nationwide effort by the Forest Service to steward Wilderness areas. “The ultimate goal of this trip was to ensure that future generations inherit landscapes and watersheds like the Stikine that continue to provide opportunities to hunt, fish, and reflect in wild places that have been available to generations before them,” said Daven Hafey of SEACC. "The Stikine is the lifeblood of Wrangell, and we want to help make sure it remains healthy." The group focused on managing the aggressive reed canary grass along the Twin Lakes shoreline by covering it with sheets of black plastic. Hand pulling and shovels were also used to remove the non-native buttercup and dandelion at the lakes’ landing. Reed canary grass is a tall grass that invades and dominates riparian areas, displacing native plants and reducing the richness and diversity of insects. Non-native buttercup and dandelion are not as aggressive, but can push out native plant species. In total, the group worked a collective 304 hours over the course of five days. [Photo caption: When the Scouts and volunteers were not pulling weeds, they had an opportunity to reaffirm their connection to the land and enjoy what it means to be in the Wilderness] Comment

Allelopathy: a tool for weed management in forest restoration

David Low / WeedsNews4237 / February 6, 2013 / 9:17:07 PM EST / 0 Comments
Abstract: Forest restoration uses active management to re-establish natural forest habitat after disturbance. However, competition from early successional species, often aggressively invasive exotic plant species, can inhibit tree establishment and forest regeneration. Ideally, restoration ecologists can plant native tree species that not only establish and grow rapidly, but also suppress exotic competitors. Allelopathy may be a key mechanism by which some native trees could reduce the abundance and impact of exotic species. Allelopathy is a recognized tool for weed management in agriculture and agroforestry, but few studies have considered how allelopathic interactions may aid restoration. Here we introduce the “Homeland Security” hypothesis, which posits that some naïve exotic species may be particularly sensitive to allelochemicals produced by native species, providing a tool to reduce the growth and impacts of invasive exotic species on reforestation. This article explores how exploiting allelopathy in native species could improve restoration success and the re-establishment of natural successional dynamics. We review the evidence for allelopathy in agroforestry systems, and consider its relevance for reforestation. We then illustrate the potential for this approach with a case study of tropical forest restoration in Panama. C4 grasses heavily invade deforested areas in the Panama Canal watershed, especially Saccharum spontaneum L. We measured the effect of leaf litter from 17 potential restoration tree species on the growth of invasive C4 grasses. We found that leaf litter from legume trees had a greater inhibitory effect on performance of S. spontaneum than did litter from non-legume trees. However, allelopathic effects varied greatly among species within tree functional groups. Further evaluation of intra- and inter-specific interactions will help to improve our selection of restoration species. [Justin A. Cummings, Ingrid M. Parker & Gregory S. Gilbert (2012). Allelopathy: a tool for weed management in forest restoration. Plant Ecology, 213(12), 1975-1989] Comment

Agrochemicals in field margins—assessing the impacts of herbicides, insecticides, and fertilizer on the common buttercup (Ranunculus acris)

David Low / WeedsNews4231 / February 4, 2013 / 8:19:45 PM EST / 0 Comments
Abstract: The effects of herbicide, insecticide, and fertilizer inputs on the common buttercup Ranunculus acris in field margins were studied in an experimental field study. The test design allowed us to investigate the single and combined effects of repeated herbicide, insecticide, and fertilizer applications in successive growing seasons. To assess the effects of the agrochemical applications on R. acris plant community, assessments were carried out and a photodocumentation of the flowering intensity was performed over two years. In addition, the authors conducted a monitoring survey of R. acris in field margins in the proximity of the study site. In the field experiment, R. acris plant density decreased significantly with treatments including fertilizer. The herbicide caused a sublethal effect by reducing flower intensity by 85%. In the long run, both effects will result in a decline of R. acris and lead to shifts in plant communities in field margins. This was confirmed by the monitoring survey, where R. acris could hardly be observed in field margins directly adjacent to cereal fields, whereas in margins next to meadows the species was recorded frequently. Besides the implications for the plants, the sublethal effects may also affect many flower-visiting insects. The results indicate that the current risk assessment for nontarget plants is insufficiently protective for wild plant species in field margins and that consideration of sublethal effects is crucial to preserve biodiversity in agricultural landscapes. [Juliane Schmitz, Karoline Schäfer & Carsten A. Brühl (2013). Agrochemicals in field margins—assessing the impacts of herbicides, insecticides, and fertilizer on the common buttercup (Ranunculus acris). Environmental Toxicology and Chemistry, online 28 Jan 2013.] [Photo via CalPhotos] Comment

Glyphosate-resistant weed problem extends to more species, more farms

David Low / WeedsNews4226 / February 2, 2013 / 9:56:01 PM EST / 0 Comments
[Farm Industry News 29 Jan 2013] -- The area of U.S. cropland infested with glyphosate-resistant weeds has expanded to 61.2 million acres in 2012, according to a survey conducted by Stratus Agri-Marketing. Nearly half of all U.S. farmers interviewed reported that glyphosate-resistant weeds were present on their farm in 2012, up from 34% of farmers in 2011. The survey also indicates that the rate at which glyphosate-resistant weeds are spreading is gaining momentum; increasing 25% in 2011 and 51% in 2012. The Stratus Glyphosate Resistance Tracking study is conducted annually. It’s now in its third year. In 2012, Stratus completed interviews with nearly 3,000 farmers during the summer and fall. “We asked farmers to share their experiences with glyphosate resistance on their farms and we’re clearly seeing the problem intensify,” explains Stratus Agri-Marketing vice president Kent Fraser. Increases were reported in most states but especially in the Midwest. Not only are glyphosate-resistant weeds spreading geographically, the problem is also intensifying with multiple species now resistant on an increasing number of farms. “There is a very high rate of resistance in the southern states like Georgia where 92% of growers reported having glyphosate-resistant weeds,” reports Fraser. “And we’re also seeing the problem intensify in the midwest. In Illinois, 43% of farmers reported having glyphosate-resistant weeds in 2012.” Marestail (horseweed) was the weed species most commonly reported as resistant to glyphosate herbicides, followed by Palmer amaranth (pigweed). Other glyphosate-resistant weed species were also tracked in the study. In 2012, 27% of U.S. farmers reported multiple glyphosate-resistant weeds on their farm, up from 15% in 2011 and 12% in 2010. Comment

Controversial new GMO corn delayed amid protests and health concerns

David Low / WeedsNews4211 / January 30, 2013 / 9:13:22 PM EST / 0 Comments
[Reuters by Cary Gillam via Cornucopia Institute 28 Jan 2013 ] – A controversial new biotech corn developed by Dow AgroSciences, a unit of Dow Chemical, will be delayed at least another year as the company awaits regulatory approval amid opposition from farmers, consumers and public health officials. Dow AgroSciences officials said Friday that they now expect the first sales of Enlist for planting in 2014. Previously officials had set the 2013 planting season as a target, but U.S. farmers are already buying seed for planting this spring, and Dow has yet to secure U.S. approval for Enlist. Dow wants to roll out Enlist corn, and then soybeans and cotton to be used in combination with its new Enlist herbicide that combines the weed-killers 2,4-D and glyphosate. The Enlist crops are genetically altered to tolerate treatments of the Enlist herbicide mixture. The hope is that Enlist will wipe out an explosion of crop-choking weeds that have become resistant to glyphosate alone.Opponents have bombarded Dow and U.S. regulators with an array of concerns about Enlist, which is intended to replace Monsanto Co.’s successful Roundup Ready system. Genetically altered Roundup Ready corn and soybeans now dominate the U.S. corn and soybean market. But as Roundup Ready crops have gained popularity, millions of acres of weeds have developed resistance to Roundup herbicide, causing farmers to use higher quantities of Roundup and other herbicides to try to beat back the weeds. Critics warn that adding more herbicides to already resistant weed populations will only expand and accelerate weed resistance. Some have likened the problem to a “chemical arms race” across farm country. [Image courtesy of Pl77] Comment

The elephant in the room: the role of failed invasions in understanding invasion biology

David Low / WeedsNews4208 / January 30, 2013 / 4:14:50 PM EST / 0 Comments
Abstract: Most species introductions are not expected to result in invasion, and species that are invasive in one area are frequently not invasive in others. However, cases of introduced organisms that failed to invade are reported in many instances as anecdotes or are simply ignored. In this analysis, we aimed to find common characteristics between non-invasive populations of known invasive species and evaluated how the study of failed invasions can contribute to research on biological invasions. We found intraspecific variation in invasion success and several recurring explanations for why non-native species fail to invade; these included low propagule pressure, abiotic resistance, biotic resistance, genetic constraints and mutualist release. Furthermore, we identified key research topics where ignoring failed invasions could produce misleading results; these include studies on historical factors associated with invasions, distribution models of invasive species, the effect of species traits on invasiveness, genetic effects, biotic resistance and habitat invasibility. In conclusion, we found failed invasions can provide fundamental information on the relative importance of factors determining invasions and might be a key component of several research topics. Therefore, our analysis suggests that more specific and detailed studies on invasion failures are necessary. [Zenni, R. D. and Nuñez, M. A. (2013). The elephant in the room: the role of failed invasions in understanding invasion biology. Oikos. doi: 10.1111/j.1600-0706.2012.00254.x] Comment

UK bans sale of five invasive non-native aquatic plants

David Low / WeedsNews4206 / January 29, 2013 / 11:47:34 PM EST / 0 Comments
[BBC News 29 Jan 2013 by Mark Kinver] -- Five species of invasive non-native aquatic plants are to be banned from sale, the UK government has announced. In the first ban of its kind, officials hope the move will save money and help protect vulnerable habitats. Environment Minister Richard Benyon said tackling the impact of invasive species costs £1.7bn each year. The plants to be banned from April 2014 are water fern (Azolla filiculoides), parrot's feather (Myriophyllum aquaticum), floating pennywort (Hydrocotyle ranunculoides), water primrose (Ludwigia grandiflora, Ludwigia uruguayensis and Ludwigia peploides) and Australian swamp stonecrop (Crassula helmsii). "Tough laws to curb the sale of these plants could save the country millions of pounds as well as protecting wildlife such as fish and native plants," Mr Benyon said. "But as well as saving money and protecting wildlife the ban will also help maintain access to rivers and lakes for anglers and watersport fans." A Defra spokesman told BBC News that it was the first time that non-native plants have been banned from sale in England. He added that the UK action was distinct from existing European Union safeguards that prohibit organisms harmful to native plants from entering the 27-nation bloc. The plants have been listed in the Wildlife and Countryside Act 1981, but it was only illegal to dump the plants into the wild. [Photo: Floating pennywort, one of the species to be banned, can grow up to 20cm (8in) per day.] Comment

Ecological tradeoffs in non-native plant management

David Low / WeedsNews4204 / January 28, 2013 / 2:52:40 PM EST / 0 Comments
Abstract: Controlling non-native plants in natural areas should, ideally, not only reduce target species’ abundance, but also benefit broader management objectives such as conserving native species, improving wildlife habitat, and maintaining ecosystem function. In this context, the effectiveness and non-target impacts of control strategies, such as broadleaf herbicides, must be weighed against the impacts of non-native plants themselves. We undertook this relative assessment for Centaurea stoebe, one of the most widespread and heavily managed non-native plant species in the Intermountain West, USA. While effectiveness and plant community impacts of herbicide treatment for C. stoebe have been assessed, field-based experiments quantifying community-level impacts of C. stoebe are rare. In a three-year experiment in sagebrush–grassland communities of southwest Montana, USA, we found that the broadleaf herbicide, picloram, was highly effective at reducing C. stoebe, but also caused a significant loss of native forb cover and a significant increase in non-native grass cover, primarily Bromus tectorum. There was a significant increase in native forb cover in response to manual removal of C. stoebe, which would seem to indicate C. stoebe had been suppressing native forbs. However, there was an equivalent increase in native forb cover with no treatment. In some communities, C. stoebe appears to have a negligible effect on native forb and grass cover and richness. Depending on management objectives, the loss of native forb cover and potential secondary invasion may outweigh the benefits of reduced target non-native plant abundance; thus, highlighting an ecological tradeoff of non-native plant management in natural areas. [Tanya C. Skurski, Bruce D. Maxwell & Lisa J. Rew (2013). Biological Conservation, 159, 292-302.] Comment

Terrestrial pesticide exposure of amphibians: An underestimated cause of global decline?

David Low / WeedsNews4202 / January 28, 2013 / 1:27:15 PM EST / 0 Comments
Abstract: Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide [including two herbicide] products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group. [Carsten A. Brühl, Thomas Schmidt, Silvia Pieper & Annika Alscher (2013). Terrestrial pesticide exposure of amphibians: An underestimated cause of global decline? Scientific Reports, Vol 3, Article number 1135. doi:10.1038/srep01135] [Photo: A red-eyed treefrog (Agalychnis callidryas): more than one-third of all amphibians are endangered. Photograph: Peter Lilja/Getty Images via The Guardian] Comment

Exotic tree seedlings are much more competitive than natives but show underyielding when growing together

David Low / WeedsNews4198 / January 25, 2013 / 1:55:45 PM EST / 0 Comments
Abstract: Invasive species continue to be a worldwide threat to ecosystems mainly as a cause for biodiversity loss. Forest ecosystems, for example, are subject to a change in species composition due to the invasion of exotic species. Specifying the attributes that cause the strong competitiveness of several exotic species may improve the ability to understand and effectively manage plant invasions in the future. In this study the following hypotheses were tested: (1) biomass production of below- and aboveground plant components of the exotic tree species is higher than that of the natives, resulting in a higher competitiveness of the exotics; (2) the exclusion of root competition has a positive effect on the biomass production of the inferior native species; and (3) mixtures of native and exotic species yield a higher biomass production than the respective monocultures. Method: A pot experiment, containing about 2000 tree seedlings, was established. We investigated the biomass productivity and growth reactions of two native (Quercus robur L., Carpinus betulus L.) and two exotic tree species (Prunus serotina Ehrh., Robinia pseudoacacia L.) in different intra- and interspecific, competitive situations with and without the influence of root competition. Important findings: The biomass production of both exotic species was significantly higher and led to a strong competitive advantage, resulting in a biomass decrease of the less competitive native species. The high belowground biomass of both exotic species had a negative effect on the biomass production. The competitive pressure of exotic tree seedlings on the native ones was largely driven by root competition. Furthermore, mixtures of native and exotic tree species had a higher productivity than their growth in monocultures would have predicted. Competition was lower for exotic species in mixtures with the less productive native species compared to the competition in monocultures or in mixture with the other highly productive exotic species. Accordingly, both highly competitive exotic species produced less biomass in mixture with each other compared to monocultures. Despite the significantly higher biomass of P. serotina in all mixtures and in monoculture, R. pseudoacacia seemed to be the dominating species. Due to its strong root competition, R. pseudoacacia significantly reduced the biomass production of P. serotina. [Heike Kawaletz, Inga Mölder , Stefan Zerbe , Peter Annighöfer, André Terwei & Christian Ammer (2013). Exotic tree seedlings are much more competitive than natives but show underyielding when growing together. Journal of Plant Ecology, online 23 January 2013] Comment

Increased cancer burden among pesticide applicators and others due to pesticide exposure

David Low / WeedsNews4194 / January 24, 2013 / 11:58:25 AM EST / 0 Comments
Abstract: A growing number of well-designed epidemiological and molecular studies provide substantial evidence that the pesticides used in agricultural, commercial, and home and garden applications are associated with excess cancer risk. This risk is associated both with those applying the pesticide and, under some conditions, those who are simply bystanders to the application. In this article, the epidemiological, molecular biology, and toxicological evidence emerging from recent literature assessing the link between specific pesticides and several cancers including prostate cancer, non-Hodgkin lymphoma, leukemia, multiple myeloma, and breast cancer are integrated. Although the review is not exhaustive in its scope or depth, the literature does strongly suggest that the public health problem is real [i.e., not fictional]. If we are to avoid the introduction of harmful chemicals into the environment in the future, the integrated efforts of molecular biology, pesticide toxicology, and epidemiology are needed to help identify the human carcinogens and thereby improve our understanding of human carcinogenicity and reduce cancer risk. CA Cancer J Clin 2013;. © 2013 American Cancer Society. [Alavanja, M. C. R., Ross, M. K. & Bonner, M. R. (2013). Increased cancer burden among pesticide applicators and others due to pesticide exposure. CA: A Cancer Journal for Clinicians, online 15 Jan 2013. doi: 10.3322/caac.21170] Comment

Potential classical biological control of invasive Himalayan yellow raspberry, Rubus ellipticus (Rosaceae)

David Low / WeedsNews4193 / January 24, 2013 / 11:19:51 AM EST / 0 Comments
Abstract: Rubus ellipticus is one of the world's worst invasive alien species. It is a serious problematic weed in Hawai‘i and has naturalized in many other countries. Biological control is being considered as a means to suppress it by introducing natural enemies from Asia, its native region. In this paper, we report 62 herbivorous insect species in 22 families that were collected on R. ellipticus during 2006–2010 in China. Two leaf-rolling moth species, Epinotia ustulana and Epiblema tetragonana; two warty beetle species, Chlamisus setosus and Chlamisus sp.; two flea beetle species in the genus Chaetocnema; four unidentified weevil species; five unidentified buprestids; one pyralid species; and one sawfly species were considered important. We also report results of preliminary host-range determinations for some of them. In addition, we summarize the literature on natural enemies associated with Rubus species in Asia, which encompasses 50 arthropod species in 14 families and 63 fungi species in 18 orders. [ Kai Wu, Ted D. Center, Chunhua Yang, Jun Zhang, Jialiang Zhang, & Jianqing Ding (2013). Potential classical biological control of invasive Himalayan yellow raspberry, Rubus ellipticus (Rosaceae). Pacific Science, 67(1):59-80. doi: dx.doi.org/10.2984/67.1.5] Comment

Twenty-five years of plant community dynamics and invasion in New Zealand tussock grasslands

David Low / WeedsNews4192 / January 24, 2013 / 10:37:50 AM EST / 0 Comments
Abstract: Understanding how plant communities respond to plant invasions is important both for understanding community structure and for predicting future ecosystem change. In a system undergoing intense plant invasion for 25 years, we investigated patterns of community change at a regional scale. Specifically, we sought to quantify how tussock grassland plant community structure had changed and whether changes were related to increases in plant invasion. Frequency data for all vascular plants were recorded on 124, permanent transects in tussock grasslands across the lower eastern South Island of New Zealand measured three times over a period of 25 years. Multivariate analyses of species richness were used to describe spatial and temporal patterns in the vegetation. Linear mixed-effects models were used to relate temporal changes in community structure to the level and rate of invasion of three dominant invasive species in the genus Hieracium while accounting for relationships with other biotic and abiotic variables. There was a strong compositional gradient from exotic- to native-dominated plant communities that correlated with increasing elevation. Over the 25 years, small-scale species richness significantly decreased and then increased again; however, these changes differed in different plant communities. Exotic species frequency consistently increased on some transects and consistently declined on others. Species richness changes were correlated with the level of Hieracium invasion and abiotic factors, although the relationship with Hieracium changed from negative to positive over time. Compositional changes were not related to measured predictors. Our results suggest that observed broad-scale fluctuations in species richness and community composition dynamics were not driven by Hieracium invasion. Given the relatively minor changes in community composition over time, we conclude that there is no evidence for widespread degradation of these grasslands over the last 25 years. However, because of continuing weed invasion, particularly at lower elevations, impacts may emerge in the longer term. [Day, N. J. & Buckley, H. L. (2013). Twenty-five years of plant community dynamics and invasion in New Zealand tussock grasslands. Austral Ecology. doi: 10.1111/aec.12016] Comment

‘Stacked’ trait technology draws criticism


David Low / WeedsNews4190 / January 23, 2013 / 9:09:49 AM EST / 0 Comments

[The Western Producer Jan. 18th, 2013 by Robert Arnason] -- Canadian and American weed scientists want an answer to a provocative question: how will applying more herbicides solve the problem of herbicide resistant weeds in North America?
 Four Agriculture Canada weed experts and professors from Oregon State and Montana State universities argued in a 2012 paper published in the journal Weed Science that combining new herbicide tolerant genes in genetically modified plants that already contain herbicide tolerant traits is not the answer to the widespread challenge of glyphosate resistance.
 Last year, the Canadian Food Inspection Agency approved a Dow-Agrosciences technology that stacks 2,4-D tolerance on top of glyphosate tolerance. 
The company expects to launch its Enlist weed control system for corn in 2013 and soybeans in 2015, pending approval in the United States.
 Monsanto has developed TruFlex canola, which is expected to serve as a base for future stacked trait technology, and allows for a wider window for glyphosate applications. 
The company also expects to introduce genetically modified soybean seed next year that combines dicamba tolerance with its existing Roundup Ready technology.
 Weed scientists have hailed stacked resistance as a key tool to fight gly-phosate resistant weeds, but others, such as Neil Harker of Agriculture Canada in Lacombe, Alta., aren’t buying the arguments.
 “It’s just another way of delaying the inevitable,” he said.
 “What you do by stacking technology is you get a reprieve for a few years and then (you) eventually select for multiple resistance.”
 Instead of relying on technology for a solution, Harker and the authors of the Weed Science paper, including John O’Donovan, Hugh Beckie and Robert Blackshaw of Agriculture Canada, want to set herbicide-frequency reduction targets for major field crops in Canada and the U.S. Comment

Global plant diversity still hinges on local battles against invasives, study suggests

David Low / WeedsNews4185 / January 20, 2013 / 9:39:05 PM EST / 0 Comments
[ScienceDaily Jan. 17, 2013] — In Missouri forests, dense thickets of invasive honeysuckle decrease the light available to other plants, hog the attention of pollinators, and offer nutrient-stingy berries to migrating birds. They even release toxins to make it less likely native plants will germinate near them. Why, then, are recent popular science articles recommending a recalibration of the traditional no-tolerance attitude toward non-native species, suggesting that we've been "unfair" to invasives and should stop "persecuting" them? Kristin Powell, a graduate student in the lab of Tiffany Knight, associate professor of biology and director of the Environmental Studies Program in Arts & Sciences, together with consulting ecologist Jon Chase, think they've located one source of misunderstanding. Most scientific studies of the effects of invasive plants are done at a single "scale." Some studies scrutinize biodiversity in meter-square "quadrats" and others scan biodiversity in entire islands or regions. The problem, the scientists say in the January 18 issue of Science, is that the effect of invasive plants on species richness depends on scale. Invasives decrease species richness at small but not at large scales. The recognition that findings are scale dependent reconciles at least some dueling scientific studies. "I won't say we've resolved the debate, but I think we've made an important contribution," Knight says. [Photo: Bush honeysuckle, introduced to USA in the late 1800s as an ornamental and to provide bird-nesting habitat is taking over the understory of a Missouri oak-hickory forest. “Honeysuckle stands are so dense, nothing walks through them except deer, so they’re full of spider webs and dust,” says Powell. (Credit: Kristin Powell)] Comment

Advocacy group reviews India's lack of pesticide laws

David Low / WeedsNews4177 / January 18, 2013 / 9:15:15 PM EST / 0 Comments
[CSE 16 January 2013] -- The Indian public interest research and advocacy group, Centre for Science and Environment, has published a review of the country’s pesticide regulations. The report examines how and where pesticides are used in the country, the most common human exposure routes, and acceptable and possible daily intakes by people of potentially dangerous pesticides. Of the 234 pesticides registered in India, 59 were found to have no set maximum residue limit (MRL). A review of 11 important crops in India was also undertaken — wheat, paddy, apple, mango, potato, cauliflower, black pepper, cardamom, tea, sugarcane and cotton. The paper shows that the pesticide recommendations made by state agriculture universities, agriculture departments and other boards for these crops do not conform to the pesticides that the Central Insecticides Board and Registration Committee (CIBRC) has registered for those crops. The agriculture universities, departments and boards were found to be recommending many pesticides that have not been registered for some of crops they were being recommended for. An analysis of 10 common pesticides showed that waiting periods for many of their registered uses (crop-pest/weed/disease combination) have not been recommended. Farmers were found to be unaware of the registered uses of pesticides. Farmers most commonly applied pesticides as dealers recommended. Outreach of state agriculture universities and departments to the farmers was minimal. Download the full report (pdf) Comment

Soil properties in organic olive orchards following different weed management in a rolling landscape of Andalusia, Spain

David Low / WeedsNews4170 / January 17, 2013 / 2:26:17 PM EST / 0 Comments
Abstract: This study evaluated the most significant physical, chemical and biological soil properties from a group of organic olive farms located in a typical olive-growing area of Andalusia, Spain, after 5 or more years since the shift from conventional to organic farming, and compared soils with those in nearby undisturbed (U) natural areas. Two soil management systems implemented in these organic olive farms to control weeds, tillage (T), characterized by non-inverting-shallow tillage in spring, and mechanical mowing (M), were compared and evaluated against the U areas. Organic olive orchards showed similar productivity (average fruit yield of 3130 kg ha−1 yr−1) as the conventional, rain-fed olive groves in the same area, with no significant differences due to soil management systems. Soil properties in the olive orchards (i.e. texture, pH, organic carbon (C), organic nitrogen (N), C:N ratio, cation exchange capacity (CEC) and exchangeable potassium) were in the suitable range for olive farming in both soil managements, although organic C and N, saturated hydraulic conductivity and available water-holding capacity (AWC) of the soil were lower than in the U areas. A principal component analysis (PCA) for soil properties in topsoil (0–10 cm depth) distinguished the T from M olive orchards and U areas, and determined organic C and N as the most significant soil properties to characterize them. Average values of soil organic carbon (SOC) stocks for the surface layer (0–10 cm depth) were 18.6, 59.3 and 67.8 Mg ha−1, for T and M soil management systems and U areas, respectively. This indicates that the sustainability of organic olive orchards could be significantly improved by shifting to M soil management to decrease soil erosion and depletion of SOC. [ María-Auxiliadora Soriano, Sonia Álvarez, Blanca B. Landa & José A. Gómez (2012). Soil properties in organic olive orchards following different weed management in a rolling landscape of Andalusia, Spain. Renewable Agriculture and Food Systems, on-line 20 Dec 2013. dx.doi.org/10.1017/S1742170512000361] Comment

Industrial and cultural preferences drive global food waste, engineers say

David Low / WeedsNews4164 / January 16, 2013 / 10:47:18 PM EST / 0 Comments
[IMechE 10 Jan 2013] -- Advocates for synthetic herbicides and genetic engineering often claim our growing population will starve if we do not embrace their increasingly difficult to manage technologies. There is a far more environmentally benign way forward to feeding the world that does not have the unwanted side effects of chemical bombardment or gene stacking. The world currently wastes up to 2 billion metric tons of food each year, driven by supermarket industry practices, inefficient harvesting and agriculture methods, poor storage and processing facilities and Western culture’s penchant for perfect looking fruits and vegetables, according to report by the UK Institution of Mechanical Engineers.Waste Not Want Not – Global Food Waste: Feeding the 9 Billion” describes how up to half of the four billion metric tons of food produced each year never makes it to the plate. As a result, large amount of land, water, energy and fertilisers are wasted as well, the report says. The authors call for initiatives to be taken to reduce the substantial quantity of food wasted annually around the world. The potential to provide 60–100% more food by simply eliminating losses, while simultaneously freeing up land, energy and water resources for other uses, is an opportunity that should not be ignored. Comment

Persistence of native flora in invaded habitats can mask eventual extinction, claim researchers

David Low / WeedsNews4161 / January 16, 2013 / 9:47:41 PM EST / 0 Comments
[University of Toronto 9 Jan 2013] — Given time, invading plants will most likely eliminate native species growing in the wild, new research shows. Previous statements that find invasive plants are not problematic are often based on incomplete information, with insufficient time having passed to observe the full effect of invasions on native biodiversity, according to a study published in Proceedings of the National Academy of Sciences. “The impacts of exotic plant invasions often take much longer to become evident than previously thought,” says Benjamin Gilbert of the Department of Ecology & Evolutionary Biology at the University of Toronto and lead author of the study. “This delay can create an ‘extinction debt’ in native plant species, meaning that these species are slowly going extinct but the actual extinction event occurs hundreds of years after the initial invasion. ”Much of the debate surrounding the threat posed to biodiversity by the invasions of non-native species is fueled by recent findings that competition from introduced plants has driven remarkably few plant species to extinction. Instead, native plant species in invaded ecosystems are often relegated to patchy, marginal habitats unsuitable to their non-native competitors." However, Gilbert and co-author Jonathan Levine of ETH Zurich say that it is uncertain whether the colonization and extinction dynamics of the plants in marginal habitats will allow long-term native persistence.“Of particular concern is the possibility that short term persistence of native flora in invaded habitats masks eventual extinction,” says Levine. The scientists conducted their research in a California reserve where much of the remaining native plant diversity exists in marginal areas surrounded by invasive grasses. They performed experiments in the reserve and coupled their results with quantitative models to determine the long term impacts of invasive grasses on native plants. Comment

United Kingdom warned to take action on pesticides

David Low / WeedsNews4158 / January 16, 2013 / 8:50:56 PM EST / 0 Comments
[Farmers Weekly 10 Jan 2013 by Johan Tasker] -- UK Government ministers have failed to grasp the seriousness of challenges posed by the withdrawal of important pesticides, scientists and farm leaders have warned. More research in alternative crop protection is needed to meet demand for food as pesticides are taken off the market due to European legislation, the UK's Department for Environment, Food & Rural Affairs (DEFRA) has been told. The warning is contained in an open letter to farm minister David Heath from Professor Toby Bruce, of the Association of Applied Biologists, and National Farmers Union (NFU) president Peter Kendall. "Farmers need to be supported by more practical R&D that will provide them with workable alternative crop protection techniques," the letter says. Farmers use pesticides as the mainstay of their crop protection because they provide a straightforward and effective way of reducing losses to pests, weeds and diseases, it adds. "Reducing the availability of certain pesticides before alternative crop protection methods have been implemented would mean an increase in the use of the remaining pesticides." Comment

Effects of Roundup® and glyphosate on three food microorganisms: Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus

David Low / WeedsNews4154 / January 14, 2013 / 10:06:28 AM EST / 0 Comments
Abstract: Use of many pesticide products poses the problem of their effects on environment and health. Amongst them, the effects of glyphosate with its adjuvants and its by-products are regularly discussed. The aim of the present study was to shed light on the real impact on biodiversity and ecosystems of Roundup, a major herbicide used worldwide, and the glyphosate it contains, by the study of their effects on growth and viability of microbial models, namely, on three food microorganisms (Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus) widely used as starters in traditional and industrial dairy technologies. The presented results evidence that Roundup has an inhibitory effect on microbial growth and a microbicide effect at lower concentrations than those recommended in agriculture. Interestingly, glyphosate at these levels has no significant effect on the three studied microorganisms. Our work is consistent with previous studies which demonstrated that the toxic effect of glyphosate was amplified by its formulation adjuvants on different human cells and other eukaryotic models. Moreover, these results should be considered in the understanding of the loss of microbiodiversity and microbial concentration observed in raw milk for many years. [Emilie Clair, Laura Linn, Carine Travert, Caroline Amiel, Gilles-Eric Se´ralini & Jean-Michel Panoff (2012). Effects of Roundup® and glyphosate on three food microorganisms: Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus. Current Microbiology, 64(5), 486-491.] Comment

Management of invasive plant species in Nigeria through economic exploitation: Lessons from other countries

David Low / WeedsNews4148 / January 8, 2013 / 10:47:31 PM EST / 0 Comments
Abstract: Invasive alien species, once they made entry into a region or country, often become difficult to eradicate and it appears that they have come to stay. Worse still, their adverse effects on the native biodiversity are enormous and they are considered ecologically harmful. Agricultural and economic losses to invasive species are comparatively high. Mechanical control is expensive and difficult in some terrains; chemical control is also expensive, requires constant application and has its environmental implications, while biological control is mirred with mixed failures and successes. This paper reviewed that economic exploitation of some notorious invasive species in other countries – such as Sudan, Ethiopia, India, Senegal, Mali and the Gambia – and how this had helped reduce the spread of these invasives and at the same time, became source of income to the poor people. It is believed that adopting this concept in Nigeria will create incentives for harvesting invasive species with more commitment, while it is an indirect way of controlling them. Furthermore, harvesting could be labour intensive, thus creating jobs for people, while it provides additional means of income for rural people, which is a key adaptation strategy for climate change. [Temitope Israel Borokini and Folaranmi Dapo Babalola (2012). Management of invasive plant species in Nigeria through economic exploitation: Lessons from other countries. Management of Biological Invasions, 3(1), 45-55)] Comment

Response of Lolium perenne to repeated flame treatments with various doses of propane

David Low / WeedsNews4146 / December 28, 2012 / 9:38:52 PM EST / 0 Comments
Abstract: In many urban areas, use of herbicides is either unwanted or prohibited and replaced with flame weeding. The influence of dose (kg propane ha−1) and treatment interval of flame weed control was studied on Lolium perenne. Lolium perenne is a perennial grass that is very difficult to control with non-chemical weed control methods, because of its extensive regrowth. Treatments of eight different doses and five treatment intervals were applied during two seasons from May to October. The response was measured as plant dry weight, 14 days after last treatment. All weeds were killed with doses above 80 kg propane ha−1 when treatments were carried out every other week (10 treatments per growing season and a total dose of 800 kg ha−1), and no regrowth was seen the following 2 weeks. Six treatments a year and a total dose of 631–674 kg ha−1, depending on year, controlled L. perenne effectively (90% reduction in dry weight). Split applications generally increased the effect of the treatments, especially when the number of treatments was increased from four to six. The results are in accordance with the assumption that repeated flame treatments are necessary to kill larger plants and heat tolerant weeds, such as grasses and perennial weeds that will regrow after a single treatment. Knowledge of the relation between dose and treatment intervals may be used to improve flame weeding strategies on hard surfaces. [Rask AM, Andreasen C & Kristoffersen P (2012). Response of Lolium perenne to repeated flame treatments with various doses of propane. Weed Research 52, 131–139.] Comment

Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity

David Low / WeedsNews4140 / December 20, 2012 / 2:05:34 PM EST / 0 Comments
Abstract: Pesticides are always used in formulations as mixtures of an active principle with adjuvants. Glyphosate, the active ingredient of the major pesticide in the world, is an herbicide supposed to be specific on plant metabolism. Its adjuvants are generally considered as inert diluents. Since side effects for all these compounds have been claimed, we studied potential active principles for toxicity on human cells for 9 glyphosate-based formulations. For this we detailed their compositions and toxicities, and as controls we used a major adjuvant (the polyethoxylated tallowamine POE-15), glyphosate alone, and a total formulation without glyphosate. This was performed after 24 h exposures on hepatic (HepG2), embryonic (HEK293) and placental (JEG3) cell lines. We measured mitochondrial activities, membrane degradations, and caspases 3/7 activities. The compositions in adjuvants were analyzed by mass spectrometry. Here we demonstrate that all formulations are more toxic than glyphosate, and we separated experimentally three groups of formulations differentially toxic according to their concentrations in ethoxylated adjuvants. Among them, POE-15 clearly appears to be the most toxic principle against human cells, even if others are not excluded. It begins to be active with negative dose-dependent effects on cellular respiration and membrane integrity between 1 and 3 ppm, at environmental/occupational doses. We demonstrate in addition that POE-15 induces necrosis when its first micellization process occurs, by contrast to glyphosate which is known to promote endocrine disrupting effects after entering cells. Altogether, these results challenge the establishment of guidance values such as the acceptable daily intake of glyphosate, when these are mostly based on a long term in vivo test of glyphosate alone. Since pesticides are always used with adjuvants that could change their toxicity, the necessity to assess their whole formulations as mixtures becomes obvious. This challenges the concept of active principle of pesticides for non-target species. [R. Mesnager, B. Bernay & G.-E. Séralini (2012). Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity. Toxicology, online 20 Sept. 2012] Comment

Continued diuron use risks killing Australia's Great Barrier Reef

David Low / WeedsNews4138 / December 20, 2012 / 1:35:07 PM EST / 0 Comments
[The Australian 28/11/12] -- A Federal Australian Government decision to reinstate the use of diuron on weeds in water bodies is not enough to protect the Great Barrier Reef despite new conditions, conservationists say. The Australian Pesticides and Veterinary Medicines Authority (APVMA) suspended the use of some diuron products in 2011 pending a review of the chemical, used on weeds and algae in and around water bodies. The APVMA has affirmed the registration of most diuron products with new conditions of use, APVMA spokeswoman Susan Whitbread said. Restrictions have been put in place for the spraying of individual crops and no-spray times will apply to sugarcane and pineapple crops. "We have made a considerable effort to develop workable instructions for the continued use of diuron, while ensuring we can effectively manage risks from the use of this environmentally mobile and persistent chemical," Ms Whitbread says. Approval for industrial applications and use in non-agricultural situations, citrus, apples and pears, ornamental plants and tropical crops including tea, coffee and paw paw has been rejected. The rate of application has been restricted and farmers will not be able to spray when heavy or persistent rain is forecast. WWF spokesman Nick Heath said the decision would result in the continued contamination of freshwater systems and marine environments and put the health of Australians at risk. The chemical is classified in the United States as a known or likely carcinogen. It has been linked to coral bleaching and seagrass die-back on the Great Barrier Reef, accounting for 80 per cent of the herbicide pollution on the reef, Mr Heath said. "The APVMA has again failed to protect the Great Barrier Reef," he said. Comment

Quantifying vapor drift of dicamba herbicides applied to soybean

David Low / WeedsNews4137 / December 20, 2012 / 1:20:39 PM EST / 0 Comments
Abstract: Recent advances in biotechnology have produced cultivars of corn, soybean, and cotton resistant to the synthetic-auxin herbicide dicamba. This technology will allow dicamba herbicides to be applied in new crops, at new periods in the growing season, and over greatly expanded areas, including postemergence applications in soybean. From past and current use in corn and small grains, dicamba vapor drift and subsequent crop injury to sensitive broadleaf crops has been a frequent problem. In the present study, the authors measured dicamba vapor drift in the field from postemergence applications to soybean using greenhouse-grown soybean as a bioassay system. They found that when the volatile dimethylamine formulation is applied, vapor drift could be detected at mean concentrations of 0.56 g acid equivalent dicamba/ha (0.1% of the applied rate) at 21 m away from a treated 18.3 × 18.3 m plot. Applying the diglycolamine formulation of dicamba reduced vapor drift by 94.0%. With the dimethylamine formulation, the extent and severity of vapor drift was significantly correlated with air temperature, indicating elevated risks if dimethylamine dicamba is applied early to midsummer in many growing regions. Additional research is needed to more fully understand the effects of vapor drift exposures to nontarget crops and wild plants. [J. Franklin Egan & David A. Mortensen (2012). Quantifying vapor drift of dicamba herbicides applied to soybean. Environ. Toxicol. Chem., 31: 1023–1031.] Comment

U.S. agricultural research is faltering, report warns

David Low / WeedsNews4133 / December 19, 2012 / 8:29:39 PM EST / 0 Comments
[The New York Times 19 Dec 2012 by Stephanie Strom] -- A blue-ribbon panel of scientific and technology advisers to President Obama warns that the nation risks losing its longstanding supremacy in food production because research in agriculture has not kept up with new challenges like climate change, depleted land and water resources and emerging pests, pathogens and invasive plants. The president’s Council of Advisers on Science and Technology, chaired by John P. Holdren, director of the White House office of science and technology policy, and Eric Lander, president of the Broad Institute of Harvard University and the Massachusetts Institute of Technology, urged a commitment of $700 million in additional money for new agricultural research — but deployed in very different ways than the money that is currently doled out. “Our most important conclusion is that our nation’s agricultural research enterprise is not prepared to meet the challenges that U.S. agriculture faces in the 21st century,” the panel states in its report, which was issued on Friday. The report lays out seven challenges ranging from competition for water to the impacts of climate change and biofuels production on food yields. “The need to deal with these growing challenges in agriculture, including new pests and pathogens, controlling agriculture’s environmental impact, health and nutritional concerns and international food security underscores the importance of agricultural research to the health, prosperity and security of the nation,” they wrote. But the panel found that federal money for agricultural research has, in real dollars, remained roughly the same for the last 30 years, according to the report, while financing for research in other areas of science and technology has risen strikingly. [Photo:Darren Hauck/Reuters -Clouds of dust associated with a fungus called smut, which is brought on by heat and drought, infected fields near Belleville, Wis., this year.] Comment

Assessing the invasion risk of Eucalyptus in the United States using the Australian weed risk assessment

David Low / WeedsNews4131 / December 18, 2012 / 9:58:29 PM EST / 0 Comments
Abstract: Many agricultural species have undergone selection for traits that are consistent with those that increase the probability that a species will become invasive. However, the risk of invasion may be accurately predicted for the majority of plant species tested using the Australian Weed Risk Assessment (WRA). This system has been tested in multiple climates and geographies and, on average, correctly identifies 90% of the major plant invaders as having high invasion risk, and 70% of the noninvaders as having low risk. We used this tool to evaluate the invasion risk of 38 Eucalyptus taxa currently being tested and cultivated in the USA for pulp, biofuel, and other purposes. We predict 15 taxa to have low risk of invasion, 14 taxa to have high risk, and 9 taxa to require further information. In addition to a history of naturalization and invasiveness elsewhere, the traits that significantly contribute to a high invasion risk conclusion include having prolific seed production and a short generation time. Selection against these traits should reduce the probability that eucalypts cultivated in the USA will become invasive threats to natural areas and agricultural systems. [Doria R. Gordon, S. Luke Flory, Aimee L. Cooper, & Sarah K. Morris (2012). Assessing the invasion risk of Eucalyptus in the United States using the Australian weed risk assessment. International Journal of Forestry Research, 2012 Issue, pp 1-7, doi:10.1155/2012/203768] Comment

Impact of managing cover crop residues on the floristic composition and species diversity of the weed community of pepper crop (Capsicum annuum L.)

David Low / WeedsNews4129 / December 17, 2012 / 9:40:14 PM EST / 0 Comments
Abstract: The decline of farmland biodiversity is mainly attributed to the intensive use of chemical inputs in agriculture. Cover crop residues may contribute to improve weed management while maintaining a high level of weed diversity. A 2-year field experiment was carried out in central Italy to study the effect of cover crop species and their residue management on weed community composition and weed species diversity in a winter cover crop – pepper sequence. Hairy vetch (Vicia villosa Roth.), oat (Avena sativa L.) and canola (Brassica napus L.) were sown in September 2009 and 2010 and grew undisturbed during the winter season until spring when they were suppressed one week before pepper transplanting. Cover crop residues were: (i) green manured at 30 cm depth (conventional tillage, CT), (ii) green manured at 10 cm depth (minimum tillage, MT), and (iii) left on the soil surface as mulch strips covering 50% of the ground area in no-tilled soil (NT). A winter weedy fallow and a bare soil without cover crop in NT, MT and CT were also included as controls. Weed plant density data in pepper were used for calculating weed species richness. Compared to weedy fallow, oat, hairy vetch and canola consistently reduced the weed density and weed aboveground biomass by the time of their suppression (on average 3.6, 21.5, and 41.3 plants m−2 and 11.0, 49.2, and 161.8 g m−2 of DM, respectively). In pepper, oat residues generally determined a higher reduction of weed density and species richness compared to hairy vetch and canola regardless the residue management treatments. Converting cover crop aboveground biomass into mulch strips greatly reduced weed species density but did not always imply a reduction of weed species diversity in pepper compared to MT and CT. The weed species richness was reduced inside the mulch strips, while a richer and more diverse weed community was found outside the mulch strips in NT. Weed community in pepper was mainly composed of annual dicot weeds such as Amaranthus retroflexus, Chenopodium album, Solanum nigrum, Polygonum aviculare which were mostly associated with MT and CT tillage systems, while in NT an increase of perennial species such as Rumex crispus was observed. These results suggest that it is possible to manage cover crop residues in NT in order to obtain a lower weed density and consequently a higher yield in pepper compared to MT and CT while maintaining a high level of weed diversity. [Emanuele Radicetti, Roberto Mancinelli & Enio Campiglia (2012). Impact of managing cover crop residues on the floristic composition and species diversity of the weed community of pepper crop (Capsicum annuum L.). Crop Protection, Volume 44, February 2013, Pages 109–119.] Comment

Corporate push for GMO food puts independent science in jeopardy

David Low / WeedsNews4117 / December 13, 2012 / 1:52:16 PM EST / 0 Comments
[The Asian Age 05 Dec 2012 by Dr Vandana Shiva] -- Science is considered science when it is independent, when it has integrity and when it speaks the truth about its search. It was the integrity, independence and sovereignty of science that drew me and propelled me to study physics. Today, independent science is threatened with extinction. While this is true in every field, it is the field of food and agriculture that I am most concerned about. At the heart of the food and agriculture debate are genetically modified organisms, also referred to as GMOs. The agrochemical industry’s new avatar is as the GMO industry. According to the industry, GMOs are necessary to remove hunger and are safe. But evidence from all independent scientists has established that GMOs do not contribute to food security. The UN-sponsored International Assessment of Agricultural Science and Technology for Development (IAASTD) report — written by 400 scientists after a research of three to four years — concluded that there is no evidence that GMOs increase food security. The Union of Concerned scientists concluded in its report, “A Failure to Yield”, that in the US, genetic engineering had not increased the yield.The GMO Emperor Has No Clothes” — a Global Citizens’ report on the state of GMOs based on field research across the world — also found that genetic engineering has not increased yields. Yet, the propaganda continues that GMOs are the only solution to hunger because GMOs increase yields. Comment

Monsanto on verge of $US40 million GMO bailout in Europe: Report

David Low / WeedsNews4116 / December 13, 2012 / 1:32:01 PM EST / 0 Comments
[The Natural Independent 28 Nov 2012 by Nicholas Tamasi] -- The genetically modified food industry’s biggest player, Monsanto, is reportedly set to receive $US 40 million worth of financial support from the European Bank for Reconstruction and Development according to the website bankwatch.org. The monetary assists/bailout will be offered for contracts made by the U.S. GMO giant with medium and large farmers and distributors in countries such as Bulgaria, Russia, Serbia, Turkey, Ukraine and Hungary. It was not clear in the article what impact GMO bans in places such as Hungary and Russia would have on the situation. The funds will go to companies that cannot pay for either seeds or the wide variety of agrochemicals sold by Monsanto that they had originally committed to buy but aren’t able to afford. The news is not likely to be well received by the legions of anti-GMO activists in Europe and other affected areas. Genetically modified organisms have been linked to various negative health effects including allergies and even organ damage and cancer. Russia banned American GMO imports following a French study showing massive tumors in lab rats that consumed GMO corn as well as Monsanto’s Roundup, its controversial, signature weed killing chemical that has also been linked to cancer. The announcement is the latest in a series of events and articles showing that Monsanto is seen as “too big to fail” by powerful government interests from the U.S. to Europe even as the movement for GMO freedom grows by the day. Wikileaks earlier revealed that United States diplomats essentially work for Monsanto to push their products and seeds around the world. President Barack Obama has appointed two former top Monsanto employees, Michael Taylor and Tom Vilsack, to high ranking food/safety positions in the U.S. government. Comment

Mulches can be used as an effective chemical-free alternative to manual or chemical weed control in peach

David Low / WeedsNews4115 / December 13, 2012 / 12:10:55 PM EST / 0 Comments
Abstract: An experiment was conducted to study the effect of mulches and herbicides on weed population, fruit yield, and quality in peach cv. ‘Earli Grande.’ Covering soil with black polythene mulch (100 μm) resulted in 100% control of weeds at six weeks after treatment (WAT) during both the years of study. However, guinea grass, which had emerged out of the black polythene mulch, reduced the weed control efficiencies (WCE) to 96.3 and 98.5% in 2009 and 2010, respectively, at 12 WAT. Application of straw mulch (8 cm, 15.5 t ha− 1) resulted in higher weed control efficiencies at 6 WAT during 2009 and 2010 (98.4 and 98.2%, respectively). At 12 WAT, this decreased to 90.7 and 93.1% in 2009 and 2010, respectively, due to the emergence of bermuda grass and guinea grass from the mulch. The weed control efficiencies with treatments having diuron as pre-emergence herbicide did not differ significantly from black polythene at 6 WAT. Atrazine and pendimethalin were the next most efficient and did not differ significantly from each other. At 12 WAT, diuron followed by fb glyphosate resulted in higher WCE, and it did not differ significantly from atrazine fb glyphosate. In both years, highest fruit yield (69.3 and 67.9 kg tree− 1, respectively) was recorded with straw mulch (8 cm). Straw mulch (8 cm) also resulted in a 20 and 19% increase in fruit weight (81.9 and 81.4 g during 2009 and 2010, respectively) over manual weeding. Straw mulch (8 cm) did not differ significantly from straw mulch (6 cm), black polythene mulch, and diuron treatments for fruit yield during both years. Conclusively, plastic and straw mulches can be used as an effective chemical-free alternative to manual or chemical weed control in peach. [Anirudh Thakur, Harminder Singh, S. K. Jawandha & Tarundeep Kaur (2012). Mulching and herbicides in peach: Weed biomass, fruit yield, size, and quality. Biological Agriculture & Horticulture: An International Journal for Sustainable Production Systems, 28(4)] Comment

How native plants and exotics coexist

David Low / WeedsNews4114 / December 13, 2012 / 10:33:14 AM EST / 0 Comments
[ScienceDaily Nov. 30, 2012] — When people hear about exotic plants invading a new environment, there is usually a negative connotation, according to biology faculty member Matthew Heard in an article published in the journal Ecology Letters. They often think of plants like kudzu, Chinese privet, or Japanese honeysuckle, whose thuggish behavior can push out the native plants in their backyard or local parks. While this worse case scenario can happen, it isn't always the case, said Heard, who wrote his Ph.D. dissertation at Brown University on how native and exotic plants coexist along the coasts of Rhode Island and Massachusetts. "It turns out that in many places, native and exotic plants can actually live together," Heard said. "And this means that exotic plants aren't inherently bad like many people think, but it also means that it is important to figure out what is driving this balance between these two groups." In his paper, Heard notes that there has been little experimental fieldwork conducted to determine what factors allows native and exotic plants to live side by side. While there have been many potential explanations tossed out, it turns out that just being different is the main reason that they can actually coexist together. "Basically, we found that exotics plants grow more and can essentially out-compete natives, which normally is a problem. But in these communities there are also insects, which prefer to eat exotic plants instead of natives and can keep their growth in check. As a result, native plants, which are less susceptible to these insects can thrive even when exotic plants that are better competitors are nearby," said Heard. How long this precarious balance will remain is unknown, but for now it isn't just the case of exotic species being problematic. Instead it's the story of how differences between two groups of plants allow them to survive along side each other. Comment

Biological invasions: a field synopsis, systematic review, and database of the literature

David Low / WeedsNews4113 / December 13, 2012 / 10:13:27 AM EST / 0 Comments
Abstract: Species introductions of anthropogenic origins are a major aspect of rapid ecological change globally. Research on biological invasions has generated a large literature on many different aspects of this phenomenon. Here, we describe and categorize some aspects of this literature, to better understand what has been studied and what we know, mapping well-studied areas and important gaps. To do so, we employ the techniques of systematic reviewing widely adopted in other scientific disciplines, to further the use of approaches in reviewing the literature that are as scientific, repeatable, and transparent as those employed in a primary study. We identified 2398 relevant studies in a field synopsis of the biological invasions literature. A majority of these studies (58%) were concerned with hypotheses for causes of biological invasions, while studies on impacts of invasions were the next most common (32% of the publications). We examined 1537 papers in greater detail in a systematic review. Superior competitive abilities of invaders, environmental disturbance, and invaded community species richness were the most common hypotheses examined. Most studies examined only a single hypothesis. Almost half of the papers were field observational studies. Studies of terrestrial invasions dominate the literature, with most of these concerning plant invasions. The focus of the literature overall is uneven, with important gaps in areas of theoretical and practical importance. [Edward Lowry, Emily J. Rollinson, Adam J. Laybourn, Tracy E. Scott, Matthew E. Aiello-Lammens, Sarah M. Gray, James Mickley & Jessica Gurevitch (2012). Biological invasions: a field synopsis, systematic review, and database of the literature. Ecology and Evolution. doi: 10.1002/ece3.431] Comment

Complementing biological control with plant suppression: implications for improved management of parthenium weed (Parthenium hysterophorus L.)

David Low / WeedsNews4112 / December 13, 2012 / 9:55:10 AM EST / 0 Comments
Abstract: Parthenium hysterophorus L., is a weed of global significance that has become a major weed in Australia and many other parts of the world. A combined approach for the management of parthenium weed using biological control and plant suppression, was tested under field conditions over a two-year period in southern central Queensland. The six suppressive plant species, selected for their demonstrably suppressive ability in earlier glasshouse studies, worked synergistically with the biological control agents (Epiblema strenuana Walker, Zygogramma bicolorata Pallister, Listronotus setosipennis Hustache and Puccinia abrupta var. partheniicola) present in the field to reduce the growth (above ground biomass) of parthenium weed, by between 60 to 86% and 47 to 91%, in Years 1 and 2, respectively. The biomass of the suppressive plants was between 6% and 23% greater when biological control agents were present than when the biological control agents had been excluded. This shows that parthenium weed can be more effectively managed by combining the current biological control management strategy with selected sown suppressive plant species, both in Australia and elsewhere. [Asad Shabbira, Kunjitapatham Dhileepanb, Chris O’Donnella & Steve W. Adkins (2012). Complementing biological control with plant suppression: implications for improved management of parthenium weed (Parthenium hysterophorus L.). Biological Control, online 8 Dec. dx.doi.org/10.1016/j.biocontrol.2012.11.014] Comment

Sustainable weed control strategy at winery wins international recognition

David Low / WeedsNews4104 / December 6, 2012 / 10:38:14 AM EST / 0 Comments
Kalleske Wines in Australia's Barossa Valley have been awarded the 2012 Advantage SA InterContinental Sustainability Award for implementing sustainability measures to minimise their environmental footprint. Genuine sustainability and careful environmental practices are at the core of Kalleske farming, grape growing and winemaking. Kalleske control weeds by suppressing mid-row weeds over winter with a green-manure cover crop of cereal and legume that in spring is mowed/worked into the soil. This provides nutrients and organic matter. Under-vine weeds are controlled mechanically with a weeder blade/dodger or via mowing. Managing weeds this way ensures a loose permeable soil which is open to maximum rainfall penetration. By avoiding synthetic herbicides, earthworms and soil microbes are protected, ensuring a highly biologically active soil and subsequent benefits. Certified organic and biodynamic practices in the vineyard and winery not only result in top quality grapes and award-winning wine, but ensure soil, air and waterways are not polluted with synthetic chemicals and fertilisers. Organic viticulture also results in more carbon being retained in the soil, (making it healthier) instead of finding its way into the atmosphere as carbon dioxide. Kalleske were also recognised for generating their own solar electricity on site and have become water self-sufficient by capturing and storing rainwater from the winery and farm sheds. (Photo: Tony Kalleske accepting the award with Brian Hurn - Barossa Mayor) Comment

No pesticide use week celebrated throughout Asia

David Low / WeedsNews4101 / December 4, 2012 / 8:53:55 PM EST / 0 Comments
This December, different communities and grassroots organisations all over Asia will celebrate "No Pesticide Use Week" as part of the ongoing struggle for a pesticide-free world. The week will focus on highlighting the dangers of highly hazardous pesticides, advancing healthier alternatives and increasing awareness on corporate accountability over health and environmental poisoning. On December 3, we commemorate the tragic chemical industry disaster in Bhopal, India while on December 10 we celebrate the International Human Rights Day. Fora, workshops, cultural shows and street plays, dialogues on biodiversity-based ecological agriculture, and street actions will be held in India, Sri Lanka, China, the Philippines, Indonesia, Viet Nam, Lao PDR, Cambodia, and many more ….

Eliminate pesticide exposure in children

David Low / WeedsNews4100 / December 4, 2012 / 8:38:29 PM EST / 0 Comments
Abstract: Pesticides are a collective term for a wide array of chemicals intended to kill unwanted insects, plants, molds, and rodents. Food, water, and treatment in the home, yard, and school are all potential sources of children’s exposure. Exposures to pesticides may be overt or subacute, and effects range from acute to chronic toxicity. In 2008, pesticides were the ninth most common substance reported to poison control centers, and approximately 45% of all reports of pesticide poisoning were for children. Organophosphate and carbamate poisoning are perhaps the most widely known acute poisoning syndromes, can be diagnosed by depressed red blood cell cholinesterase levels, and have available antidotal therapy. However, numerous other pesticides that may cause acute toxicity, such as pyrethroid and neonicotinoid insecticides, herbicides, fungicides, and rodenticides, also have specific toxic effects; recognition of these effects may help identify acute exposures. Evidence is increasingly emerging about chronic health implications from both acute and chronic exposure. A growing body of epidemiological evidence demonstrates associations between parental use of pesticides, particularly insecticides, with acute lymphocytic leukemia and brain tumors. Prenatal, household, and occupational exposures (maternal and paternal) appear to be the largest risks. Prospective cohort studies link early-life exposure to organophosphates and organochlorine pesticides (primarily DDT) with adverse effects on neurodevelopment and behavior. Among the findings associated with increased pesticide levels are poorer mental development by using the Bayley index and increased scores on measures assessing pervasive developmental disorder, inattention, and attention-deficit/hyperactivity disorder. Related animal toxicology studies provide supportive biological plausibility for these findings. Additional data suggest that there may also be an association between parental pesticide use and adverse birth outcomes including physical birth defects, low birth weight, and fetal death, although the data are less robust than for cancer and neurodevelopmental effects. Children’s exposures to pesticides should be limited as much as possible. [James R. Roberts & Catherine J. Karr (2012). Pesticide exposure in children. The American Academy of Pediatrics, Technical Report - online 26 Nov 2012.] Comment

Degradation and leaching of fluroxypyr after application to railway tracks

David Low / WeedsNews4094 / December 4, 2012 / 2:57:26 PM EST / 0 Comments
Abstract: Fluroxypyr is an auxin-type herbicide used for postemergent control of broad-leaved weeds in agriculture and in nonagricultural environments such as railways. The overall aim of this study was to assess the potential environmental impact from fluroxypyr application to railway tracks and to elucidate some of the factors that control its environmental fate. In laboratory studies, we examined the degradation of fluroxypyr and the formation of its metabolites fluroxypyr-methoxypyridine (F-MP) and fluroxypyr-pyridinol (F-P) in soil from two Swedish railways. We also investigated the degradation and leaching of fluroxypyr in three different railway plots treated with fluroxypyr (360 g ae ha−1). The half-life of fluroxypyr in soil samples ranged between 28 and 78 d. An estimated mean 48.6 ± 20% of the fluroxypyr was converted into F-P and 8.0 ± 2% into F-MP. The main metabolite, F-P, was rapidly degraded, with an average half-life of 10 ± 5 d. However, F-MP was not degraded to a significant degree in any sample, resulting in slowly increasing concentrations throughout the experiment. This pattern of relatively rapid degradation of F-P and slow accumulation of F-MP was also observed in the field. The persistent nature of F-MP may be of concern if fluroxypyr is used repeatedly at the same location. Fluroxypyr was detected in the groundwater beneath the track at all three locations studied in concentrations exceeding the EU limit of 0.1 μg L−1 for pesticides in drinking water, and F-P was detected in the groundwater at two of three locations. The most important factor controlling fluroxypyr degradation rate in soil was the soil water content, which modulated microbial activity and presumably also fluroxypyr availability to microorganisms. Our findings imply that fluroxypyr may not be a suitable herbicide for weed control on railway tracks. [H. Cederlund , E. Börjesson , E. Jonsson & T. Thierfelder (2012). Degradation and leaching of fluroxypyr after application to railway tracks. Journal of Environmental Quality, 41(6), 1884-1892] Comment

Weevil borne microbes contribute as much to the reduction of photosynthesis in water hyacinth as does herbivory

David Low / WeedsNews4092 / December 4, 2012 / 2:14:40 PM EST / 0 Comments
Abstract: Arthropods released for weed biocontrol can have effects other than simply removing biomass and frequently decrease photosynthetic rate more than can be attributed to the mere loss of photosynthetic surface area. Some of this effect may result because biological control agents facilitate the transfer and ingress of deleterious microbes into plant tissues on which they feed. We evaluated this facilitation effect using water hyacinth (Eichhornia crassipes) and a weevil (Neochetina eichhorniae) and compared the reductions in photosynthetic rates between leaves subject to herbivory by adult weevils sterilized with 3.5% chlorine bleach, to those that were unsterilized. The results showed that weevils carried both fungi and bacteria, transferred these to leaves on which they fed, and that microbes and biomass removal contributed almost equally to the 37% decrease in photosynthetic productivity. Hence, maximising the effectiveness of using arthropods that damage leaf surfaces for biocontrol requires the presence of microorganisms that are deleterious to plants. [Nic Venter, Martin P. Hill, Sarah-Leigh Hutchinson & Brad S. Ripley (2012). Weevil borne microbes contribute as much to the reduction of photosynthesis in water hyacinth as does herbivory. Biological Control, online 5 Nov.] Comment

Weed seeds in exogenous organic matter and their contribution to weed dynamics in cropping systems

David Low / WeedsNews4088 / December 4, 2012 / 1:53:08 PM EST / 0 Comments
Abstract: Nitrogen fertilizers are crucial for ensuring crop production. Mineral nitrogen fertilizer are often complemented or replaced (e.g. in organic agriculture) by exogenous organic matter (EOM) to limit environmental impacts of mineral fertilization (e.g. reduced carbon storage, nitrate leaching to groundwater, biodiversity erosion). EOM can though cause new problems as it comprises pest propagules, particularly weed seeds. The objective of the present work was to evaluate the impact of EOM on grass–weed dynamics, combining EOM analyses and model simulations. The first step analyzed seven EOM types for their chemical properties (e.g. nitrogen, carbon) and weed seed contents (using germination tests). The tested EOMs were of agricultural or urban origin (e.g. co-compost of green waste and sewage sludge or organic fraction of municipal waste). The most infested EOMs were composted farmyard manure and cattle slurry while fresh manure contained few weed seeds. Urban and green waste composts were nearly seed-free. In total, nineteen weed species and one crop species (Triticum aestivum) were identified with cattle slurry comprising the highest species number (thirteen). Weeds were mostly grass species (Lolium sp., Bromus sterilis, Echinochloa crus-galli, Festuca sp., Poa annua), except for Trifolium sp. In the second step, an existing model (AlomySys) which quantifies the effects of cropping systems on the dynamics of an autumnal grass weed similar to Lolium sp. was amended to account for EOM applications, considering both weed seed addition to the native soil seed bank and additional nitrogen. Finally, the amended model was used to simulate the effects on grass–weed dynamics of applying composted farmyard manure, using the observed EOM characteristics. Simulations focused on a small number of factors potentially interacting with EOM, i.e. EOM application frequency and seed content, tillage strategies, mineral nitrogen fertilization, and initial weed infestation. These simulations showed that for autumnal grass–weed species, adding weed seeds via EOM only increased multi-year weed infestation if fields were initially weed-free or if the simulated weed species was highly dormant in summer. Conversely, the additional EOM nitrogen reduced the fitness of the newly produced grass–weed seeds by affecting their dormancy and germination pattern, having more of them emerge in summer and thus unable to flower. Burying manure by mouldboard ploughing decreased or even cancelled the EOM effect. [N. Colbach, C. Tschudy, D. Meunier, S. Houot & B. Nicolardot (2013). European Journal of Agronomy, 45, 7–19.] Comment

Exposure to atrazine associated with increased risk of common birth defect

David Low / WeedsNews4084 / December 4, 2012 / 1:17:18 PM EST / 0 Comments
Abstract: Previous literature has suggested a link between maternal exposure to atrazine (the most commonly used herbicide in the US) and risk for gastroschisis (a birth defect that involves incomplete closure of the abdominal wall). Our objective was to evaluate the relationship between maternal atrazine exposure and gastroschisis risk by maternal age. We analyzed data for 1,161 cases with isolated gastroschisis and 8,390 controls delivered in Texas from 1999 through 2008. We estimated atrazine exposure based on maternal county of residence and data from the United States Geological Survey. Logistic regression was conducted among all subjects, and separately among offspring of women < 25 and > or = 25 years. Risk for gastroschisis in offspring was significantly increased for women > or = 25 years with high levels of residential atrazine exposure compared to low (adjusted odds ratio: 1.97, 95 % confidence interval 1.19–3.26). This association was not observed among women < 25 years. Our results provide additional insight into the suspected relationship of gastroschisis with atrazine. This relationship appears to be different in older versus younger mothers,providing further evidence that the etiology of gastroschisis may vary based on maternal age. [
A. J. Agopian, Peter H. Langlois, Yi Cai, Mark A. Canfield & Philip J. Lupo (2012). Maternal residential atrazine exposure and gastroschisis by maternal age. Matern Child Health J, online 25 Nov. DOI 10.1007/s10995-012-1196-3] Comment

Organic dairy farms benefit farmers and local economies, US report finds

David Low / WeedsNews4076 / November 29, 2012 / 7:13:33 AM EST / 0 Comments
[Union of Concerned Scientists 12 Nov 2012] WASHINGTON – The organic dairy sector provides more economic opportunity and generates more jobs in rural communities than conventional dairies, according to a report released today by the Union of Concerned Scientists (UCS). The first-of-its-kind study, “Cream of the Crop: The Economic Benefits of Organic Dairy Farms,” calculated the economic value of organic milk production. “Over the past 30 years, dairy farmers have had a choice: either get big or get out. Dairy farmers either had to expand dramatically and become large industrial operations or they went out of business,” said Jeffrey O’Hara, agricultural economist for the Food and Environment Program at UCS and author of the report. “However, organic dairy production offers farmers another option – one that is better for the environment, produces a healthier product, and leads to greater levels of economic activity.” Based on 2008 - 2011 financial data from two major milk-producing states—Vermont and Minnesota— the report evaluated the economic impact of organic dairy farms. Vermont’s 180 organic farms contribute $76 million annually to the state’s economy and support 1,009 jobs. In Minnesota, 114 organic farms add $78 million to Minnesota’s economy annually and have created 660 jobs. Comment

Toxic fables: the advertising and marketing of agricultural chemicals in the great plains, 1945–1985

David Low / WeedsNews4075 / November 29, 2012 / 7:01:20 AM EST / 0 Comments
Abstract: This paper examines how pesticides and their technologies were sold to farmers and pilots throughout the midtwentieth century. It principally considers how marketing rhetoric and advertisement strategies used by chemical companies and aerial spraying firms influenced the practices and perspectives of farm producers in the Great Plains. In order to convince landowners and agricultural leaders to buy their pesticides, chemical companies generated advertisements that championed local crop health, mixture accuracy, livestock safety and a chemical-farming ‘way of life’ that kept fields healthy and productive. Combining notions of safety, accuracy and professionalism with pest eradication messages reinforced the standards that landowners, pilots and agriculturalists would hold regarding toxicity and risk when spraying their fields. As the politics of health changed in the aftermath of Rachel Carson's Silent Spring, these companies and aerial spraying outfits responded by keeping to a vision of agricultural health that required poisons for protection through technological accuracy. [David D. Vail (2012). Toxic fables: the advertising and marketing of agricultural chemicals in the great plains, 1945–1985. Endeavour, online 21 Nov. dx.doi.org/10.1016/j.endeavour.2012.09.007] Photo: Early Dusting of Kansas Wheat. 1949. Flaggers were often in direct contact with the pesticides. Comment

USDA advisory committee recommends farmers must pay to insure themselves against GMO weed contamination

David Low / WeedsNews4074 / November 29, 2012 / 6:48:39 AM EST / 0 Comments
[Center for Food Safety 20 Nov 2012] Washington, D.C. – The National Organic Coalition (NOC) has sharply condemned recommendations contained in the final report of the Advisory Committee on Biotechnology and 21st Century Agriculture (AC21), a group appointed by the U.S. Department of Agriculture (USDA) to address transgenic contamination of organic and non-genetically engineered (GE) crops. Of particular concern in the report is the recommendation that organic and non-GE conventional farmers pay to self-insure themselves against unwanted GE contamination. NOC strongly asserts that this proposal allows USDA and the agricultural biotechnology industry to abdicate responsibility for preventing GE contamination while making the victim of GE pollution pay for damages resulting from transgenic contamination. “The AC21 report takes responsibility for GE contamination prevention out of the hands of USDA and the biotech industry where it belongs and puts it squarely on the backs of organic and non-GE farmers,” said Andrew Kimbrell, executive director at Center for Food Safety and a NOC member. “This ill-conceived solution of penalising the victim is fundamentally unjust and fails to address the root cause of the problem – transgenic contamination. Comment

An environmental - economic perspective on integrated weed management in Iran

David Low / WeedsNews4073 / November 28, 2012 / 9:28:49 PM EST / 0 Comments
Abstract: Inputs used in crop production, such as herbicides, generally create environmental externalities. One solution to minimizing these adverse impacts is adoption of integrated weed management (IWM) with the view of reducing herbicide use. This paper estimates farmers' willingness to pay for adoption of better weed management methods. Results also suggest that willingness to pay (WTP) for IWM is more than those for other weed management methods. Producers have a higher WTP for bio-herbicides and other efficient herbicides that manage weeds and reduce negative environmental and health impacts. These results suggest that farmers value various environmental goods and services. The study also identified factors that influence adoption of IWM on wheat farms in Iran using multinomial logit model. Results show that total annual income and area under irrigated wheat had a positive influence on the choice of IWM, while weed damage, perennial characteristics of weeds and awareness of weed resistance to herbicide had a negative effect. [Mohammad Ghorbani & Suren N. Kulshreshtha (2012). An environmental - economic perspective on integrated weed management in Iran. Weed Technology, on-line Nov 18. dx.doi.org/10.1614/WT-D-10-00122.1] Comment

Generalised pollination systems for three invasive milkweeds in Australia

David Low / WeedsNews4072 / November 28, 2012 / 12:23:00 PM EST / 0 Comments
Abstract: Because most plants require pollinator visits for seed production, the ability of an introduced plant species to establish pollinator relationships in a new ecosystem may have a central role in determining its success or failure as an invader. We investigated the pollination ecology of three milkweed species – Asclepias curassavica, Gomphocarpus fruticosus and G. physocarpus – in their invaded range in southeast Queensland, Australia. The complex floral morphology of milkweeds has often been interpreted as a general trend towards specialised pollination requirements. Based on this interpretation, invasion by milkweeds contradicts the expectation that plant species with specialised pollination systems are less likely to become invasive that those with more generalised pollination requirements. However, observations of flower visitors in natural populations of the three study species revealed that their pollination systems are essentially specialised at the taxonomic level of the order, but generalised at the species level. Specifically, pollinators of the two Gomphocarpus species included various species of Hymenoptera (particularly vespid wasps), while pollinators of A. curassavica were primarily Lepidoptera (particularly nymphalid butterflies). Pollinators of all three species are rewarded with copious amounts of highly concentrated nectar. It is likely that successful invasion by these three milkweed species is attributable, at least in part, to their generalised pollinator requirements. The results of this study are discussed in terms of how data from the native range may be useful in predicting pollination success of species in a new environment. [Ward, M., Johnson, S. D. (2012). Generalised pollination systems for three invasive milkweeds in Australia. Plant Biology. On-line 22 Nov. doi: 10.1111/j.1438-8677.2012.00700.x] Comment

The Scotch broom, Cytisus scoparius (Fabaceae), a paradox in Denmark – an invasive plant or endangered native species?

David Low / WeedsNews4066 / November 26, 2012 / 8:43:54 PM EST / 1 Comment
Abstract: Scotch broom, Cytisus scoparius, spreads rapidly in parts of Denmark and is considered an invasive species by some authors. However, the species has been present in the Danish flora for centuries and is therefore considered native to Denmark. In the present study we explore whether Danish Scotch broom consists of one or two gene pools with potential differences in phenotype and invasiveness. One plastid and five nuclear microsatellite markers were used to reveal potential substructuring of Danish Scotch broom. Nine populations were included representing populations exhibiting invasive behaviour and populations showing non-invasive behaviour. An Italian population was used as reference. Bayesian analysis based on genetic markers indicated that the sampled populations form two distinct gene pools, and this pattern was supported by neighbour-joining trees. Measurements of height and width of the analysed plants showed that the two gene pools correspond to populations exhibiting either a horizontal habit and non-invasive behaviour or an erect habit and, in some cases, invasive behaviour. The Italian population clustered with the erect ones. We discuss the origin and taxonomic status of the two gene pools and conclude that Danish horizontal Scotch broom should be given a formal taxonomic status in order to initiate conservation activities for its protection. [Rosenmeier, L., Kjær, E. D. and Nielsen, L. R. (2012). The Scotch broom, Cytisus scoparius (Fabaceae), a paradox in Denmark – an invasive plant or endangered native species? Botanical Journal of the Linnean Society. online 20 Nov 2012. doi: 10.1111/j.1095-8339.2012.01319.x] Comment

Australian farmer dies from toxic weedkiller

David Low / WeedsNews4053 / November 22, 2012 / 7:09:11 AM EST / 0 Comments
[The Courier-Mail 16 Nov, 2012 by Kate McKenna] -- THE heartbroken family of a farmer who died after being sprayed by a highly toxic weedkiller has described the man as a "gentle giant" who adored spending time with his five grandchildren. Howard Reck, 55, of Lynford in the Darling Downs, was spraying weeds on his property on Monday when the 8L pressure pump unit filled with paraquat released, spraying the poisonous chemical into his mouth and coating his face and chest. The veteran farmer drove himself 400m to a neighbouring property in a frantic dash for help. A family friend then dragged Mr Reck out of the ute and began hosing him down in a bid to wash out the poison before the ambulance arrived, his family said. Mr Reck died in Brisbane's Princess Alexandra Hospital on Tuesday. Paraquat is one of the most widely used pesticides in the world. It is used to control weeds, but as little as one teaspoonful of the active ingredient is fatal. Dr Roberto Busi from the Australian Herbicide Resistance Initiative said paraquat was widely used in agricultural farming because it was a "pre-plant knockdown" that killed all weeds, either before planting the crop or after the harvest. But the tragedy has reignited concern over Australia's regulation of highly toxic herbicides. Paraquat has courted controversy because health experts say there is no antidote, with reported links to the development of Parkinson's disease. It has been banned in 32 countries, including Finland, Sweden and China. [Photo: FAMILY DEVASTATED: Howard Reck died after exposure to the pesticide paraquat. Source: Supplied] Comment

US students pushing universities to stop using synthetic herbicides

David Low / WeedsNews4049 / November 22, 2012 / 6:31:52 AM EST / 0 Comments
[SafeLawns 19 Oct 2012 by Paul Tukey] -- Amidst pressure from student groups to change its policy of spraying synthetic chemical pesticides on campus lawns, the University of Delaware told SafeLawns it would potentially have new protocols in place by next spring. When an Oct. 9 article appeared in the school newspaper quoting two students who had been affected by the pesticide spraying for weeds — without any warning labels posted — the school responded to a student reporter by stating it only applied safe, approved products. The school still stuck to the product safety claims, but conceded that it would likely begin posting “Keep off the Grass” signs in the future. “Since the article appeared in The Review and we learned of concerns among our students, we are currently in the process of developing proper signage for the application process,” said John Brennan, the director of public and media relations for the Newark, Del., facility. “As part of this effort, we are reviewing our application policy with the Department of Environmental Health and Safety, as well as benchmarking with peer institutions regarding signage prior to implementation. At this point in the year, the lawn spraying operation has concluded and will not resume until spring, when we should have the signage issue resolved.Photo caption: Unmarked pesticide spraying at the University of Delaware has many students outraged. (Photo credit: Emily Walton) Comment

Bias and error in understanding plant invasion impacts

David Low / WeedsNews4047 / November 21, 2012 / 7:07:32 AM EST / 0 Comments
Abstract: Quantitative assessments of alien plant impacts are essential to inform management to ensure that resources are prioritized against the most problematic species and that restoration targets the worst-affected ecosystem processes. Here, we present the first detailed critique of quantitative field studies of alien plant impacts and highlight biases in the biogeography and life form of the target species, the responses assessed, and the extent to which spatial variability is addressed. Observed impacts often fail to translate to ecosystem services or evidence of environmental degradation. The absence of overarching hypotheses regarding impacts has reduced the consistency of approaches worldwide and prevented the development of predictive tools. Future studies must ensure that the links between species traits, ecosystem stocks, and ecosystem flows, as well as ecosystem services, are explicitly defined. [Philip E. Hulme, Petr Pyšek, Vojtěch Jarošík, Jan Pergl, Urs Schaffner, & Montserrat Vilà (2012). Bias and error in understanding plant invasion impacts. Trends in Ecology & Evolution, on-line 12 Nov. dx.doi.org/10.1016/j.tree.2012.10.010] Comment

A study in West Tennessee to nutritionally compare herbicide treated and non-herbicide treated bermudagrass pastures

David Low / WeedsNews4045 / November 20, 2012 / 9:13:19 PM EST / 0 Comments
Abstract: Cattle and horse producers in the Western Kentucky / Western Tennessee area depend heavily on forages to feed their livestock. Many of these farmers provide mineral supplementation without having tested the forages to see if mineral quality was sufficient for the animals' needs. In addition, cattlemen spray these fields to control weed growth (weed being any plant that was not the desired product). In this study, bermudagrass pastures that contained weeds were compared to a control field that had been sprayed for weeds in order to determine 1) if spraying was a necessary option, and 2) whether these weeds were in competition with the bermudagrass for desired nutrients. Samples were collected by hand cutting the samples, and a sample of each weed type was dug up to photograph the root systems. Samples were sorted into bermudagrass and weeds, dried and sent to a lab for testing of mineral content, CP and TDN. Statistical analysis was performed using Welch's unpaired t-test. No significant difference (P > 0.05) was determined between control bermudagrass and weedy bermudagrass for nitrogen, crude protein, potassium, magnesium, boron, iron, and aluminum. When comparing the weeds to the control, no significant difference was found for nitrogen, TDN, potassium, magnesium, calcium, iron, copper, and aluminum. Once the weed samples were combined with the bermudagrass, and compared to the control, no significant difference was found for nitrogen, potassium, magnesium, calcium, and aluminum. Root systems were determined to be in competition with the bermudagrass when the weeds were within a grass family. Other root systems were determined to be tap root systems which delve deeper for the nutrients, and therefore do not compete directly with the bermudagrass. Further study is needed to determine if spraying of weedy pastures is truly necessary. [Claxton, Angela (2012). A study in West Tennessee to nutritionally compare herbicide treated and non-herbicide treated bermudagrass pastures. Unpublished Masters Thesis, Murray State University, 85 pages] Comment

Silage for managing weed seeds

David Low / WeedsNews4041 / November 19, 2012 / 9:24:54 PM EST / 0 Comments
Abstract: Reducing the number of viable weed seeds entering a field is critical to successful weed management. Viable seeds can result from weed survivors that reach maturity, or can be imported into the field via livestock, grain, fodder, or machinery. Few reports exist on the survival of seeds in silage, or the consequence of feeding the silage to livestock. Seeds from five grass weeds, six broadleaf weeds and three pasture species were ensiled, underwent 48 hour in sacco digestion or both. Seed germination was determined after incubation at 25/15°C on a 12 hour temperature cycle. Tetrazolium staining was used to determine the viability of ungerminated seed. Seed germination and viability were compared with untreated seeds. Seed from all grass weeds except annual ryegrass were rendered unviable after being ensiled, whereas some broadleaf weed seeds remained viable. Digestion had a similar effect as ensilage on reducing seed viability, except for silverleaf nightshade and prairie ground cherry where no reduction in viability was observed. The viability of marshmallow seed and the three pasture species was not significantly reduced by either ensilage or digestion. Ensile or digestion can provide non-chemical options for effective weed management for certain weed species. [Rex Stanton, John Piltz, Craig Rodham & Hanwen Wu (2012). Silage for managing weed seeds. Eighteenth Australasian Weeds Conference, Melbourne, 8-11 October, 2012] Comment

A commercial formulation of glyphosate linked to mamalian cell death

David Low / WeedsNews4040 / November 19, 2012 / 8:53:28 PM EST / 0 Comments
Abstract: Glyphosate-based herbicides are extensively used for weed control all over the world. Therefore, it is important to investigate the putative toxic effects of these formulations which include not only glyphosate itself but also surfactants that may also be toxic. 3T3-L1 fibroblasts are a useful tool to study adipocyte differentiation, this cell line can be induced to differentiate by addition of a differentiation mixture containing insulin, dexamethasone and 3-isobutyl-1-methylxanthine. We used this cell line to investigate the effect of a commercial formulation of glyphosate (GF) on proliferation, survival and differentiation. It was found that treatment of exponentially growing cells with GF for 48 h inhibited proliferation in a dose-dependent manner. In addition, treatment with GF dilution 1:2000 during 24 or 48 h inhibited proliferation and increased cell death, as evaluated by trypan blue-exclusion, in a time-dependent manner. We showed that treatment of 3T3-L1 fibroblasts with GF increased caspase-3 like activity and annexin-V positive cells as evaluated by flow cytometric analysis, which are both indicative of induction of apoptosis. It was also found that after the removal of GF, remaining cells were able to restore proliferation. On the other hand, GF treatment severely inhibited the differentiation of 3T3-L1 fibroblasts to adipocytes. According to our results, a glyphosate-based herbicide inhibits proliferation and differentiation in this mammalian cell line and induces apoptosis suggesting GF-mediated cellular damage. Thus, GF is a potential risk factor for human health and the environment. [Claudia N. Martini, Matías Gabrielli & María del C. Vila (2012). A commercial formulation of glyphosate inhibits proliferation and differentiation to adipocytes and induces apoptosis in 3T3-L1 fibroblasts. Toxicology in Vitro, 26(6), 1007–1013. dx.doi.org/10.1016/j.tiv.2012.04.017] Comment

Present status of the development of mycoherbicides against water hyacinth: successes and challenges. A review.

David Low / WeedsNews4023 / November 14, 2012 / 2:23:52 PM EST / 0 Comments
Abstract: Recent trends in the implementation of bioherbicide use in the control of water hyacinth (Eichhornia crassipes [Martius] Solms Laubach) have depended primarily on several strategies. The use of bioherbicides has been stimulated as part of the search for alternatives to chemical control, as the use of these more environmentally-friendly formulations minimizes hazards resulting from herbicide residue to both human and animal health, and to the ecology. In addition, one of the major strategies in the concept of biological control is the attempt to incorporate biological weed control methods as a component of integrated weed management, in order to achieve satisfactory results while reducing herbicide application to a minimum. Several fungal pathogens with mycoherbicide potential (Sclerotinia sclerotiorum in HyakillTM and Cercospora rodmanii, named ABG-5003) have been discovered on diseased water hyacinth plants, but none has become commercially available in the market. Biological, technological, and commercial constraints have hindered progress in this area. Many of these constraints are being addressed, but there is a critical need to better understand the biochemical and physiological data regarding the pathogenesis of these new bioherbicides. Oil emulsions are recognized as a way to increase both efficiency of application and efficacy of biocontrol agents. [Karim Dagno, R. L.; Diourté, M.; Jijakli, M. H. (2012) Biotechnologie, Agronomie, Société et Environnement, 16(3), 360-368] Comment

Researchers say bees need weeds to boost crop yields

David Low / WeedsNews4016 / November 13, 2012 / 3:13:48 PM EST / 0 Comments
[ABC News Nov 5, 2012] AUSTRALIA -- Researchers say increasing native bee populations in broadacre crops can boost yields by up to 30 per cent. Adelaide University researcher Katja Hogendoorn has spent the past year studying bee behaviour in crops in the mid-north and Yorke Peninsula of South Australia. She says providing more food for the bees, in ways such as boosting native vegetation, can increase their numbers and improve the pollination in crops such as canola. "Canola only flowers for a short period of time and the bees are there for a longer time, so they would need extra feed, and also in years with crop rotation grains are grown [and] they will need extra food as well," she said. "If you do not have native vegetation you generally have some weeds like cape weed. If you remove all of it then you would remove that resource for them (the bees) as well, and be considerate with pesticides. "Bees are insects and they will die when insecticides are used." Comment

Did farmers of the past know more than we do?

Zheljana Peric / WeedsNews4015 / November 12, 2012 / 10:46:29 AM EST / 0 Comments
Summary: An early 18th-century agricultural experimenter Charles Townshend discovered that crops grow better, with fewer weeds and pest problems, if they are rotated in a careful sequence. Townshend’s rotation — like the ones George Washington and Thomas Jefferson used — included clover, wheat, other small grains and turnips, which made good winter food for sheep and cattle. The Romans knew about crop rotation, but by the Middle Ages, farming was based on the practice of letting the land lie fallow, unplanted — resting it, in other words. The purpose of that practice, like crop rotation itself, is to prevent the soil from becoming exhausted when the same crop is sown over and over again. In early American agriculture, only sophisticated farmers like Washington and Jefferson were using crop rotations in their fields. The Department of Agriculture, Iowa State University and the University of Minnesota shows, there’s nothing obsolete about four-crop rotation. It produces the same yields, it sharply reduces the toxicity of freshwater runoff, and it eliminates many of the problems associated with genetically modified crops, including the emergence of glyphosate-resistant weeds. It’s also simply better for the soil. The very structure of the agricultural system, as it stands now, is designed to return the greatest profit possible, not to the farmers but to the producers of the chemicals they use and the seeds they plant. And because those chemicals depend on fossil energy, the entire system is inherently unsustainable. What farmers used to return to the soil in the form of labor and animal manure — not the toxic kind you find in livestock confinement systems — they now must purchase, just the way they buy diesel for their tractors. Read the full article. Comment

Controlling annual weeds in cereals by deploying crop rotation at the landscape scale: Avena sterilis as an example

Zheljana Peric / WeedsNews4013 / November 12, 2012 / 9:09:21 AM EST / 0 Comments
Abstract: Weed control through crop rotation has mainly been studied in a nonspatial context. However, weed seeds are often spread beyond the crop field by a variety of vectors. For weed control to be successful, weed management should thus be evaluated at the landscape level. In this paper we assess how seed dispersal affects the interactions between crop rotation and landscape heterogeneity schemes with regard to weed control. A spatially explicit landscape model was developed to study both short- and long-term weed population dynamics under different management scenarios. We allowed for both two- and three-crop species rotations and three levels of between-field weed seed dispersal. All rotation scenarios and seed dispersal fractions were analyzed for both completely homogeneous landscapes and heterogeneous landscapes in which more than one crop was present. The potential of implementing new weed control methods was also analyzed. The model results suggest that, like crop rotation at the field level, crop rotation implemented at the landscape level has great potential to control weeds, whereby both the number of crop species and the cropping sequence within the crop rotation have significant effects on both the short- and long-term weed population densities. In the absence of seed dispersal, weed populations became extinct when the fraction of each crop in the landscape was randomized. In general, weed seed densities increased in landscapes with increasing similarity in crop proportions, but in these landscapes the level of seed dispersal affected which three-crop species rotation sequence was most efficient at controlling the weed densities. We show that ignoring seed dispersal between fields might lead to the selection of suboptimal tactics and that homogeneous crop field patches that follow a specific crop rotation sequence might be the most sustainable method of weed control. Effective weed control through crop rotation thus requires coordination between farmers with regard to cropping sequences, crop allocation across the landscape, and/or the fraction of each crop across the landscape. [González-Díaz, van den Berg, van den Bosch, and Luis González-Andújar (2012). Controlling annual weeds in cereals by deploying crop rotation at the landscape scale: Avena sterilis as an example. Ecological Applications 22(3):982–992. doi.org/10.1890/11-1079.1] Comment

Herbicides and breast cancer - a review

David Low / WeedsNews4011 / November 12, 2012 / 7:06:39 AM EST / 0 Comments
Abstract: Along with other etiological factors like genetics, family history, age, etc. there is growing scientific evidence that exposure to chemicals, including pesticides [and herbicides] is associated with increased incidence of breast cancer among women. Various animal studies have demonstrated the carcinogenic effect of pesticides by acting as Xenoestrogen, interacting and disrupting estrogen receptors or by damaging breast tissue DNA inducing malignancy/catalyzing existing DNA mutation in susceptible individuals. Pesticide’s role as a contributing etiological factor in growing incidence of breast cancer is of particular concern as pesticides are one of the chemicals to which humans get exposed every day in significant concentration. In this review we describe various kinds of pesticides and their respective associations to breast cancer. [Roberto Ferro, Arvin Parvathaneni, Sachin Patel, Pramil Cheriyath (2012). Pesticides and Breast Cancer. Advances in Breast Cancer Research, 1, 30-35. doi:10.4236/abcr.2012.13005] Comment

Temperature and relative humidity affect weed response to vinegar and clove oil based herbicides

David Low / WeedsNews4008 / November 9, 2012 / 9:01:41 PM EST / 0 Comments
Abstract: Non-synthetic herbicides offer a potentially useful addition to the suite of weed management tools available to organic growers, but limited information is available to guide the optimal use of these products. The objectives of this research were to 1) evaluate the efficacy of clove oil and vinegar based herbicides on weeds across multiple states, and 2) assess the potential role of temperature, relative humidity (RH) and cloud cover in explaining inter-state variations in results. From 2006 to 2008, a total of 20 field trials were conducted in 7 states using an identical protocol. Seeds of brown mustard were sown and herbicides applied to both mustard and emerged weeds when mustard reached the 3-4 leaf stage. Treatments included clove oil at 2.5, 5, 7.5, and 10% concentrations at 54 L ha-1 and vinegar at 5, 10, 15, and 20% concentrations at 107 L ha-1. Results varied widely across trials. In general, concentrations of at least 7.5% for clove oil and 15% for vinegar were needed for adequate control of mustard. Both products were more effective at suppressing mustard than Amaranthus spp. or common lambsquarters. Poor control was observed for annual grasses. No significant effects of cloud cover on the efficacy of either product were detected. In contrast, RH was positively correlated with control of brown mustard by both clove oil and vinegar with improved control at higher RH. Temperature had no detectable effect on the efficacy of clove oil, but higher temperatures improved control of brown mustard by vinegar. [Daniel Brainard, William C. Curran, Robin R. Bellinder, Mathieu Ngouajio, Mark J. VanGessel, Milton J. Haar, W T. Lanini, and John B. Masiunas (2012). Temperature and relative humidity affect weed response to vinegar and clove oil based herbicides. Weed Technology, online 26 Oct. doi: dx.doi.org/10.1614/WT-D-12-00073.1] Comment

Managing weeds on an organic farm

David Low / WeedsNews3994 / November 8, 2012 / 12:56:22 PM EST / 0 Comments
[Rodale Institute 27 Oct 2012 By Patrick Lillard] -- Ken Rider grows organic corn, soybeans, spelt and wheat on almost 500 acres in the Great Black Swamp region of Ohio, USA. As part of an Organic Agriculture Research & Extension Initiative (OREI) project looking at organic farmers’ weed management, an undergraduate student from Purdue University and I interviewed Ken. When we asked him about how he manages weeds, he quickly replied cover crops, crop rotation and cultivation, but we learned those practices were best explained through stories and experiences. Ken’s observational skills have given him an understanding of the characteristics of his soil, weed life cycles, the attributes of different cover crops, and how all of these different elements interact on his farm. He then uses these observations to experiment, to develop and test new approaches that will hopefully improve his farming system. His observations and experimentation also provide him with the knowledge to be able to quickly adapt his system to respond to challenges. Comment

Effects of wood chip mulches on weed suppression and woody plant establishment

David Low / WeedsNews3993 / November 8, 2012 / 12:45:12 PM EST / 0 Comments
Abstract: Suppressing weeds and enhancing desirable plant establishment are important when installing or maintaining landscapes. Two woodchip mulches of different particle sizes and origin were applied at different depths to assess these two criteria in transplanted Douglas fir (Pseudotsuga menziesii) and snowberry (Symphoricarpos albus) in a historically weedy field. Arborist chips and chips made from recycled wood were used, in both coarse (1.09-7.62 cm) and fine (≤1.09 cm) particle sizes, at depths of 10, 20, or 30 cm. Weed biomass was significantly affected by mulch depth; the average annual weed biomass collected was 59.4 g/m2 from non-mulched plots, and 10.9, 2.6, and 0.5 g/m2 from plots with 10, 20, and 30 cm of mulch, respectively. For two growing seasons, plant health was visually rated on a 1-5 scale (with 5 being the most healthy), and data were collected on plant height and trunk caliper. Douglas fir trees were significantly affected by particle size in both arborist and recycled wood chips, with increased health ratings, caliper, and height in the coarser chip mulch. Mean Douglas fir health ranged between 3.4−3.5 in coarse chips compared to 2.4−2.8 in fine chips. Mean Douglas fir caliper ranged between 8.0−8.2 mm in coarse chips and 4.2−6.5 mm in fine chips. Mean Douglas fir height increased in coarse chips by 19.8 cm from year 1 to year 2, but only 4.3 cm in fine chips. Snowberry was not significantly affected by either mulch treatment; given its aggressive spreading nature, this is not surprising. Ideally, wood chip mulches should be coarse (at least 1 cm) and deep (at least 20 cm) to both suppress weeds and enhance establishment of woody landscape plants. [Eric Reed Owl Eulenberg (2012). Effects of wood chip mulches on weed suppression and woody plant establishment. Dissertation: Ph.D. Washington State University, May 2012.] Comment

Bio-herbicidal properties of sorghum and sunflower aqueous extracts against germination and seedling growth of dragon spurge (Euphorbia dracunculoides Lam.).

David Low / WeedsNews3992 / November 8, 2012 / 12:36:12 PM EST / 0 Comments
Abstract: Considering allelopathy as an ecologically sound weed management approach, bio-herbicidal potential of sorghum (Sorghum bicolor L. Moench) and sunflower (Helianthus annuus L.) extracts were evaluated against germination and seedling growth of dragon spurge (Euphorbia dracunculoides L.). Different concentrations (0, 25, 50, 75, and 100%) of aqueous extracts, applied alone and in combination, were tested in a laboratory bioassay. Results revealed that germination of dragon spurge was delayed by sorghum and sunflower extracts applied alone or in combination and their different concentrations. Sorghum and sunflower aqueous extracts combined at 100% concentration inhibited seed germination 92%, while sole application of aqueous extract of sorghum was more inhibitory to dragon spurge germination (88%) than that of sunflower (80%). However at low concentrations (25 and 50%), sunflower aqueous extract performed better than the sorghum extract. All extracts concentrations exhibited a pronounced negative influence on early seedling growth of dragon spurge. Inhibition of shoot and root dry biomass by the different concentrations of the aqueous extracts was 53-86% and 49-79% for sorghum and 29-87% and 32-83% for sunflower. Their combination application inhibited shoot and root biomass 41-90% and 65-87%, respectively. The study established the bio-herbicidal potential of sorghum and sunflower aqueous extracts against dragon spurge. Their combination can be used as bio-herbicide for management of this weed. [Abdul Khaliq; Amar Matloob; Asif Tanveer; Abbas, R. N.; Khan, M. B. (2012). Bio-herbicidal properties of sorghum and sunflower aqueous extracts against germination and seedling growth of dragon spurge (Euphorbia dracunculoides Lam.). Pakistan Journal of Weed Science Research, 18(2),137-148.] Comment

Lymphoma risk and occupational exposure to pesticides: results of the Epilymph study

David Low / WeedsNews3991 / November 8, 2012 / 12:27:27 PM EST / 0 Comments
Abstract: We investigated the role of occupational exposure to specific groups of agrochemicals in the aetiology of lymphoma overall, B cell lymphoma and its most prevalent subtypes. In 1998–2003, 2348 incident lymphoma cases and 2462 controls were recruited to the EPILYMPH case-control study in six European countries. A detailed occupational history was collected in cases and controls. Job modules were applied for farm work including specific questions on type of crop, farm size, pests being treated, type and schedule of pesticide use. In each study centre, industrial hygienists and occupational experts assessed exposure to specific groups of pesticides and individual compounds with the aid of agronomists. We calculated the OR and its 95% CI associated with lymphoma and the most prevalent lymphoma subtypes with unconditional logistic regression, adjusting for age, gender, education and centre. Risk of lymphoma overall, and B cell lymphoma was not elevated, and risk of chronic lymphocytic leukaemia (CLL) was elevated amongst those ever exposed to inorganic (OR=1.6, 95% CI 1.0 to 2.5) and organic pesticides (OR=1.5, 95% CI 1.0 to 2.1). CLL risk was highest amongst those ever exposed to organophosphates (OR=2.7, 95% CI 1.2 to 6.0). Restricting the analysis to subjects most likely exposed, no association was observed between pesticide use and risk of B cell lymphoma. Conclusions: Our results provide limited support to the hypothesis of an increase in risk of specific lymphoma subtypes associated with exposure to pesticides. [Pierluigi Cocco et al. (2012). Lymphoma risk and occupational exposure to pesticides: results of the Epilymph study.Occupational & Environmental Medicine, online 01 Nov. doi:10.1136/oemed-2012-100845] http://weedsnetwork.com/db/share/wra/f%5flogo.jpg Comment

Bhutan aims to be first 100% organic nation

David Low / WeedsNews3990 / November 8, 2012 / 12:21:13 PM EST / 0 Comments
[AFP Oct 3, 2012] -- The Himalayan kingdom of Bhutan, famed for seeking "happiness" for its citizens, is aiming to become the first nation in the world to turn its home-grown food and farmers 100 percent organic. The tiny Buddhist-majority nation wedged between China and India has an unusual and some say enviable approach to economic development, centred on protecting the environment and focusing on mental well-being. Its development model measuring "Gross National Happiness" instead of Gross Domestic Product (GDP) has been discussed at the United Nations and has been publicly backed by leaders from Britain and France, among others. It banned television until 1999, keeps out mass tourism to shield its culture from foreign influence, and most recently set up a weekly "pedestrians' day" on Tuesdays that sees cars banned from town centres. Its determination to chart a different path can be seen in its new policy to phase out artificial chemicals in farming in the next 10 years, making its staple foods of wheat and potatoes, as well as its fruits, 100 percent organic. "Bhutan has decided to go for a green economy in light of the tremendous pressure we are exerting on the planet," Agriculture Minister Pema Gyamtsho told AFP in an interview by telephone from the capital Thimphu. "If you go for very intensive agriculture it would imply the use of so many chemicals, which is not in keeping with our belief in Buddhism, which calls for us to live in harmony with nature." Comment

Process for assessing new Australian Weeds of National Significance candidates

David Low / WeedsNews3988 / November 7, 2012 / 2:26:14 PM EST / 0 Comments
Abstract: Sixteen weeds were nominated as new Australian Weeds of National Significance (WoNS) candidates. The nominations were assessed against a number of criteria covering technical and policy considerations. The technical assessment was carried out using the revised WoNS prioritisation methodology. As part of the technical assessment a combination of risk models were tested in consultation with a range of experts in weed risk assessment. The different models showed consistent results in identifying the top ranking weeds and low ranking weeds, regardless of the scoring model used. The combination of using the revised WoNS prioritisation methodology, consultation with the jurisdictions, and policy considerations, formed a comprehensive and transparent assessment process. The process resulted in the selection of 12 new WoNS to be added to Australia’s ‘worst weed’ list. Comment

A European forecast: What lessons will we learn from genetically engineered herbicide tolerant crop production in Argentina and the United States?

David Low / WeedsNews3956 / November 1, 2012 / 1:11:53 PM EST / 0 Comments
Twenty six genetically engineered crops are currently being considered for approval in the European Union. 19 out of these 26 are genetically engineered to be tolerant to herbicides. Renowned agricultural economist Dr. Charles Benbrook was commissioned by Greenpeace to make the first ever forecast of how Europe would be impacted by authorising the cultivation of genetically engineered herbicide tolerant corn, soy and sugar beet. Greenpeace has also travelled through Argentina and USA to speak to farmers and their communities about how herbicide tolerant crop monocultures have affected their economy, environment and community. These first person accounts formed the basis for the documentary Growing Doubt (the film above). Witness accounts from Argentina and USA and Dr. Benbrook's forecast report present a grim view of a future Europe: the over-reliance on herbicide-tolerant crops in the U.S. has triggered the emergence and rapid spread of nearly two dozen glyphosate-resistant weeds, driving up farm production costs, as well as the volume and toxicity of herbicides needed to prevent major yield loss. Europe will face a similar reality by 2025, should herbicide tolerant genetically engineered crops be authorised for cultivation. Greenpeace is facilitating an 18 day tour of Europe with public screenings of Growing Doubt showing the reality in Argentina and USA, followed by Dr. Charles Benbrook presenting his study which you can view here. Several other renowned scientists have recently raised alarm bells over the impact of genetically modified (GM) food on our health. Ask the federal government to deliver on its election promise and make sure GM organisms are “safe beyond reasonable doubt” and properly labelled before introducing them in our food - click here to support. Comment

European perspectives on the adoption of non-chemical weed management in reduced tillage systems for arable crops

Zheljana Peric / WeedsNews3948 / November 1, 2012 / 10:58:24 AM EST / 0 Comments
Abstract: Non-inversion tillage with tine or disc based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape and maize in Europe. However, new regulations on pesticide use may hinder further expansion of reduced tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programmes based on integrated pest management (IPM) principles. Conventional non-inversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher as compared to plough-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in non-inversion tillage systems and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems but their impact in non-inversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes may become useful in reduced tillage systems where more crop residues and less workable soils are more prevalent but further development is needed for effective application.[Bo Melander, Nicolas Munier-Jolain, Raphaël Charles, Judith Wirth, Jürgen Schwarz, Rommie van der Weide, Ludovic Bonin, Peter Kryger Jensen, and Per Kudsk (2012). European perspectives on the adoption of non-chemical weed management in reduced tillage systems for arable crops. Weed Technology. Online August 30, 2012. doi.org/10.1614/WT-D-12-00066.1]. Comment

Agribusinesses recognise sustainabiltiy as a growth area and acquire biopesticide makers

David Low / WeedsNews3946 / November 1, 2012 / 9:34:06 AM EST / 0 Comments
[AgroNews 25 Sept 2012] -- Several U.S. biopesticide manufacturers have recently been snatched up by global agribusiness companies, which experts say will likely spur more research and investment in the industry. BASF, a German-based chemical company, plans to spend more than $1 billion on Becker Underwood, a producer of biological seed treatments and other products in Ames, Iowa. Syngenta, a Swiss global biotech and chemical company, will pay up to $114 million for Pasteuria Bioscience of Alachua, Fla., which uses naturally occurring soil bacteria for nematode control products. The acquisitions, both announced in mid-September, came two months after another major global chemical company -- Bayer CropScience -- said it would buy California biopesticide producer AgraQuest in a deal valued at roughly $500 million. Industry experts say biopesticides, which rely on naturally occurring substances and microorganisms, have seen tremendous sales growth in recent years. Comment

re: Solarization and organic amendments found to be viable alternatives to ozone depleting methyl bromide

David Low / WeedsNews3938 / October 31, 2012 / 9:47:44 AM EST / 0 Comments
Why is eliminating the use of methyl bromide for weeding and crop protection an issue we covered in The Weed's News last week? One important reason is covered in the following: [ACES 30 Oct 2012] -- People tend to think of ozone as merely something in the upper atmosphere that protects the earth’s surface from UV radiation. At the ground level, however, ozone is a pollutant that damages crops, particularly soybean. Potential increases in background ozone are predicted to increase soybean yield losses by 9 to 19 percent by 2030. Lisa Ainsworth, a University of Illinois associate professor of crop sciences and USDA Agricultural Research Service plant molecular biologist explained that, “Ozone reacts very quickly once it enters the leaf through the stomata. It can form other oxygen radicals and also hydrogen peroxide. Then a series of cascading reactions causes a decrease in photosynthesis, reducing stomata conductance.” The plant’s response to ozone mimics a hypersensitive response to a pathogen attack. “At quite high concentrations of ozone, you can get leaf bronzing, stippling of the leaves, and necrotic spots,” Ainsworth said. “At really high concentrations, you get cell death.” The metabolic changes then feed forward to affect plant productivity. Comment

Venus and Mars are lovers – so why “weed warriors”: A cosmological exploration

David Low / WeedsNews3933 / October 30, 2012 / 9:15:52 PM EST / 0 Comments
Abstract: Conventional attempts to control, prevent, manage or eradicate weeds chemically are poisoning the Earth. Weeds are considered an ‘enemy’ of agriculture, ecology and the average urban gardener or landscaper. The language surrounding weed issues is often highly emotionally charged. Some common words and phrases used in weed discourse are “A War on Weeds”, “Weed Warriors”, “Danger”, “Toxic” and “Weed Killer”. Viewed from a Jungian astrological perspective, all these terms and phrases are embodied in the Mars Archetype. Mars is the ancient God of War and in every war there needs to be an enemy. In the case of weed control, the enemy is nature. Weeds are plants doing what comes naturally to them. It is said that nature abhors a vacuum, and moves to fill that space. Weeds see an empty, neglected unused, unwanted and unloved space and so move in to fill it. In astrological lore Venus is the remedy for an out-of-balance Mars. The archetype of Venus is associated with the earth, agriculture, culture and cultivation, sharing, befriending and compromising, as well as love and creativity. In this paper I explore how the astrological Mars in the form of the Weed Warrior Archetype is played out in current weed control methods. I then explore ideas about how Venus and Mars can work together in creative and ingenious ways to foster a beneficial relationship for both nature and ourselves. [Peric, Z. (2012). Venus and Mars are lovers – so why “weed warriors”: A cosmological exploration. Proceedings of 4th Association for the Study of Literature, Environment and Culture (Australia-New Zealand) Biennial Conference, September 1 - 2, Melbourne.] View PowerPoint Presentation Comment

Teratogenic effects of glyphosate-based herbicides: Divergence of regulatory decisions from scientific evidence

Zheljana Peric / WeedsNews3915 / October 25, 2012 / 1:40:26 PM EST / 0 Comments
Abstract: The publication of a study in 2010, showing that a glyphosate herbicide formulation and glyphosate alone caused malformations in the embryos of Xenopus laevis and chickens through disruption of the retinoic acid signalling pathway, caused scientific and regulatory controversy. Debate centred on the effects of the production and consumption of genetically modified Roundup Ready® soy, which is engineered to tolerate applications of glyphosate herbicide. The study, along with others indicating teratogenic and reproductive effects from glyphosate herbicide exposure, was rebutted by the German Federal Office for Consumer Protection and Food Safety, BVL, as well as in industry-sponsored papers. These rebuttals relied partly on unpublished industry-sponsored studies commissioned for regulatory purposes, which, it was claimed, showed that glyphosate is not a teratogen or reproductive toxin. However, examination of the German authorities’ draft assessment report on the industry studies, which underlies glyphosate’s EU authorisation, revealed further evidence of glyphosate’s teratogenicity. Many of the malformations found were of the type defined in the scientific literature as associated with retinoic acid teratogenesis. Nevertheless, the German and EU authorities minimized these findings in their assessment and set a potentially unsafe acceptable daily intake (ADI) level for glyphosate. This paper reviews the evidence on the teratogenicity and reproductive toxicity of glyphosate herbicides and concludes that a new and transparent risk assessment needs to be conducted. The new risk assessment must take into account all the data on the toxicity of glyphosate and its commercial formulations, including data generated by independent scientists and published in the peer-reviewed scientific literature, as well as the industry-sponsored studies. [Antoniou, Habib, Howard, Jennings, Leifert, Nodari, Robinson and Fagan (2012). Teratogenic effects of glyphosate-based herbicides: Divergence of regulatory decisions from scientific evidence. Environmental & Analytical Toxicology. S:4. doi.org/10.4172/2161-0525.S4-006] http://invasivespecies.org.au/db/share/wra/f%5flogo.jpg Comment

The impact, uses, and ecological role of agrestals (weeds) in two selected agroecosystems of Eastern India

Zheljana Peric / WeedsNews3914 / October 25, 2012 / 12:58:32 PM EST / 0 Comments
Abstract: Agricultural fields contain some small plants (weeds) which are known as agrestals. Generally, weeds are perceived as unwanted intruders in agro-ecosystems that compete for resources, reduce yields, and force the use of human labor and technology to prevent crop losses; but not all weeds are undesirable. Some weeds act as valuable agro-ecosystem components. They serve as nutritious foods, and important sources of fodder and medicine. Certain weeds may limit insect damage to crops. These beneficial effects indicate that weeds are not just agricultural pests, but can also play beneficial roles in the human society. So, the main objective of the study is to know about the beneficial agrestals of the district and their roles. Detailed field surveys were made in different blocks of the district to collect data about agrestals and their usefulness. These fields contain various medicinal plants such as Solanum nigrum L., Eclipta prostrata L. Oxalis corniculata L., Rungia pectinata L. etc., edible plant Amaranthus viridis L., ornamental plant Grangea maderaspatana (L.) Poir, and aromatic plant Trachyspermum copticum L. It is clear from the study that these two fields of the district contain some valuable agrestals which are used by the locals. [Dwari and Mondal (2012). The impact, uses, and ecological role of agrestals (weeds) in two selected agroecosystems of Eastern India. International Journal of Biodiversity and Conservation. 4(13):472-480. DOI: 10.5897/IJBC12.009] Comment

Weeds management in organic farming through conservation agriculture practices

Zheljana Peric / WeedsNews3913 / October 25, 2012 / 12:41:58 PM EST / 0 Comments
Abstract: Despite weeds are a serious threat to promotion of organic farming, relatively less attention is given to research on weed management. This article explores a scope of integration of conservation agriculture for weed control and soil protection under organic farming. Limitation in the use of agro-chemicals under OF promotes intensive tillage for weed control. Mostly, tillage leads to depletion of organic matter and proneness to erosion in inclined geography. Adoption of conservation agriculture reduces the intensity of soil manipulation thereby creates an unfavourable condition for weed seed germination, reduces the organic matter depletions and soil erosions. Residues on the surface invite weed and pest predators thereby reduced the weed and pest infestations in organic field. Appropriate crop rotations and cover crops management suppress weeds populations with smothering and allopathic effects. Thus, CA integration under OF could be an option for weed, pest and soil management which leads to sustainable organic plant production. [Baral, K. R. (2012). Weeds management in organic farming through conservation agriculture practices. The Journal of Agriculture and Environment. 13] Comment

Sustainable weed control in cucurbit crops: A scoping study

Zheljana Peric / WeedsNews3912 / October 25, 2012 / 11:44:38 AM EST / 0 Comments
Abstract: Weeds have a significant impact on the production of cucurbit crops in Australia, and yet relatively little work has been conducted to develop integrated and sustainable forms of weed management in these crops. In this project we sought to scope the impact of weeds on cucurbit production, identify current techniques used by growers and assess their effectiveness and sustainability, and explore innovative approaches used in Australia and overseas. The research included a review of Australian and international literature, and consultation with cucurbit growers, herbicide producers and distributors. Weeds were reported to have a significant impact on cucurbit crop yield and quality, making crop management problematic. Significant weeds include fat hen (Chenopodium album), blackberry nightshade (Solanum nigrum), caltrop or cathead (Tribulus terrestris), pigweed/purslane (Portulaca oleracea), African lovegrass (Eragrostis curvula), barnyard grass (Echinochloa spp.), and nutgrass (Cyperus rotundus). A successful integrated weed control strategy usually involves a mix of herbicide use, plastic mulch, cultivation, chipping, crop rotation and farm hygiene. Diligence and timing are important factors in a successful approach. However, the ongoing success of this approach is not assured, due to lack of herbicide options, noted instances of herbicide resistance, and questions about the long-term sustainability of plastic mulch. Innovation is therefore required to sustain Australia’s cucurbit industry. Options include registering new herbicides, developing a viable biodegradable mulch film, and exploring promising techniques such as living and killed mulches, controlled traffic farming, stale and false seedbeds, and thermal weeding.[Coleman, Sindel, Kristiansen (2012). Sustainable weed control in cucurbit crops: A scoping study. Proceedings 16th Capturing Opportunities and Overcoming Obstacles in Australian Agronomy, Armidale, October 2012]. Photo Caption: common curcubit crops Comment

Bio-herbicidal properties of sorghum and sunflower aqueous extracts against germination and seedling growth of dragon spurge (Euphorbia dracunculoides Lam.)

Zheljana Peric / WeedsNews3910 / October 25, 2012 / 11:27:23 AM EST / 0 Comments
Anstract: Considering allelopathy as an ecologically sound weed management approach, bio-herbicidal potential of sorghum (Sorghum bicolor L. Moench) and sunflower (Helianthus annuus L.) extracts were evaluated against germination and seedling growth of dragon spurge (Euphorbia dracunculoides L.). Different concentrations (0, 25, 50, 75, and 100%) of aqueous extracts, applied alone and in combination, were tested in a laboratory bioassay. Results revealed that germination of dragon spurge was delayed by sorghum and sunflower extracts applied alone or in combination and their different concentrations. Sorghum and sunflower aqueous extracts combined at 100% concentration inhibited seed germination 92%, while sole application of aqueous extract of sorghum was more inhibitory to dragon spurge germination (88%) than that of sunflower (80%). However at low concentrations (25 and 50%), sunflower aqueous extract performed better than the sorghum extract. All extracts concentrations exhibited a pronounced negative influence on early seedling growth of dragon spurge. Inhibition of shoot and root dry biomass by the different concentrations of the aqueous extracts was 53-86% and 49-79% for sorghum and 29-87% and 32-83% for sunflower. Their combination application inhibited shoot and root biomass 41-90% and 65-87%, respectively. The study established the bio-herbicidal potential of sorghum and sunflower aqueous extracts against dragon spurge. Their combination can be used as bio-herbicide for management of this weed. [Khaliq, Matloob, Tanveer, Abbas and Khan (2012). Bio-herbicidal properties of sorghum and sunflower aqueous extracts against germination and seedling growth of dragon spurge (Euphorbia dracunculoides Lam.). Pakistan Journal of Weed Science Research. 18(2): 137-14.] Comment

Solarization and organic amendments found to be viable alternatives to ozone depleting methyl bromide

David Low / WeedsNews3905 / October 24, 2012 / 8:22:18 AM EST / 1 Comment
Abstract: Florida vegetable growers have relied on methyl bromide (MeBr) fumigation to manage soil pathogens, nematodes, and weeds. This system combined with raised beds, polyethylene mulch, and seepage and/or drip irrigation has been effective for producing high vegetable yields. Alternatives to MeBr such as solarization and organic amendments have given favorable results in small trials, but there are few large-scale studies. The objectives of this study were to evaluate the effects of long-term organic amendment applications and soil sanitation treatments on weed and nematode populations on pepper (Capsicum annuum L.) and watermelon (Citrullus lanatus [Thunb.] Manst.). During 1998 and 1999 fall vegetable seasons, main plots received a yearly organic amendment (biosolids) application or a non-amendment control, with sub-plots consisting of soil sanitation treatments with solarization, MeBr, Telone® (1,3-dichloropropene), or a non-fumigated control. Each sub-plot was further divided into two sub-sub-plots, one receiving additional weed and without control weed control. During the solarization period (60 d in 1998–1999; 90 d in 1999–2000), percent weed cover was higher in the non-biosolid plots than the biosolid plots for the first part of the solarization period, but there were no differences during the last 30 days in both seasons. Purple nutsedge was able to germinate on the north edge of the beds for a border effect; a point of vulnerability when beds run east–west. With the pepper crop, the number of weeds and percent weed cover were greater in the non-fumigated plots and Telone®-treated plots than in plots treated with MeBr or in solarized plots with and without biosolids. Nematode population densities from plot to plot within the site were highly variable, which likely accounted for the relatively few consistent effects from treatments observed during the experiment. The data do provide some indication of the importance of weeds in the recovery and buildup of nematode populations. During spring 1999, both root-knot and stubby-root nematodes were more abundant in the sub-sub-plots that had not received weed control. The results suggest that solarization and organic amendments can be viable alternatives to MeBr. However, MeBr produced the most consistent results. [Monica Ozores-Hampton, Robert McSorley & Philip A. Stansly (2012). Effects of long-term organic amendments and soil sanitation on weed and nematode populations in pepper and watermelon crops in Florida. Crop Protection, Volume 41, November 2012, Pages 106–112] Comment

Short-term gain and long-term pain: Lessons learnt from the control of Lachnagrostis filiformis (fairy grass) in Victoria, Australia

David Low / WeedsNews3903 / October 24, 2012 / 6:18:16 AM EST / 0 Comments
Abstract: The indigenous Lachnagrostis filiformis colonized extensive areas of dry lake beds in Victoria, Australia, during the drought from 1997 to 2009. Large numbers of the plants' detached seed heads disperse in the wind, lodging against nearby housing, fences and other obstacles. This accumulation of material creates a fire hazard, degrades townships' aesthetics and presents a nuisance to the communities of lake-side towns. This study aimed to examine the effects of various control methods on L. filiformis in the short and long term. Although herbicide applications, slashing, grazing and burning were found to be effective in controlling the blown L. filiformis seed heads in the short term, they failed to prevent subsequent reinvasion and can increase its abundance in the long term. The late application of herbicide resulted in an increase in the foliage cover and seed-head biomass of L. filiformis by up to 37% and 150%, respectively, in the year following the treatment application. The results from this study highlight how management focused on achieving short-term goals, without consideration of the successional trajectory after implementation, can not only fail but be counter-productive in the long term. In order to achieve sustainable management, the fundamental ecological processes that promote the establishment and persistence of the weed need to be addressed. [Warnock, A. D., Florentine, S. K., Graz, F. P. and Westbrooke, M. E. (2012). Short-term gain and long-term pain: Lessons learnt from the control of Lachnagrostis filiformis (fairy grass) in Victoria, Australia. Weed Biology and Management, online 18 Oct. doi: 10.1111/j.1445-6664.2012.00448.x] Comment

Effect of 10 years of organic dairy farming on weed populations

David Low / WeedsNews3900 / October 21, 2012 / 6:03:04 AM EST / 0 Comments
Abstract: To determine whether converting to organic farming increases weed problems, a trial at Massey University in New Zealand split a dairy farm in half, with one half farmed conventionally for 10 years and the other half farmed using organic principles. Weed populations in selected paddocks of each farmlet were studied for 8 years to determine how these populations would differ between the two systems. After 10 years, weed problems differed little between the two farmlets. Both still had broad-leaved dock (Rumex obtusifolius L.) and hairy buttercup (Ranunculus sardous Crantz) as their main weed species. Weeds were most noticeable in pastures in the year following regrassing activities for either farmlet, but being unable to use glyphosate during seed-bed preparation or use selective herbicides after sowing of new swards, meant weeds were sometimes worse in organic pastures after resowing than in conventional pastures. These weed problems were dealt with over the first few years after resowing by good grazing management, and ensuring pastures were dense once the annual species hairy buttercup had flowered and died, thus minimising any further establishment. Results from the trial suggest that weeds need not be an impediment to organic dairying. [Harrington, K. (2012). Effect of 10 years of organic dairy farming on weed populations. Eighteenth Australasian Weeds Conference, Melbourne, 8-11 October, 2012.] Comment

Optimising agro-waste in mulching: An alternative to power generation

David Low / WeedsNews3882 / October 18, 2012 / 2:52:48 PM EST / 0 Comments
Abstract: Agricultural waste generated by several agricultural activities has many alternative uses. Unfortunately much of it is burnt in the open fields leading to environmental pollution. For the management of agro-waste one way adopted is to produce electricity using this agro-waste as fuel. But Agro-waste power generation faces majors risks like fuel availability and unstable prices, problems of ash melting, slagging, clinkerisation at the base of boilers, super heater choking, agglomeration and drop in boiler temperature due to moisture in the bales. All these problems results in frequent shut downs of the plants and they do not operate continuously. Transportation of agro-waste from fields to power generation plants add to gas emission and labour cost. The other alternative for efficiently utilisation of agrowaste like paddy straw and rice husk is mulching. Mulching technically means covering of soil. Mulch provide the conditions that are favourable for the growth of plant and crop production. It is observed that mulching saves the irrigation water by increasing moisture retention of soil and suppresses weeds. This study was conducted to determine the optimal amount of mulching to save the irrigation water, because excessive use of crop residue as mulch is also not beneficial from economical point of view. The amount of optimal mulching is determined to be 8 tonnes per hectare. Further, mulching saves 45% of the commercial cost by way of reduced irrigation. [Jagmohan Singh (2012). Optimising agro-waste in mulching: An alternative to power generation. Thesis submitted in partial fulfillment of the requirement for the award of degree of Master of Engineering in Electronic Instrumentation and Control, Thapar University, India.] Comment

DNA damage in fish (Anguilla anguilla) exposed to a glyphosate-based herbicide – Elucidation of organ-specificity and the role of oxidative stress

Zheljana Peric / WeedsNews3881 / October 18, 2012 / 2:47:57 PM EST / 0 Comments
Abstract: Organophosphate herbicides are among the most dangerous agrochemicals for the aquatic environment. In this context, Roundup®, a glyphosate-based herbicide, has been widely detected in natural water bodies, representing a potential threat to non-target organisms, namely fish. Thus, the main goal of the present study was to evaluate the genotoxic potential of Roundup® in the teleost fish Anguilla anguilla, addressing the possible causative involvement of oxidative stress. Fish were exposed to environmentally realistic concentrations of this herbicide (58 and 116 μg L−1) during one or three days. The standard procedure of the comet assay was applied to gill and liver cells in order to determine organ-specific genetic damage. Since liver is a central organ in xenobiotic metabolism, nucleoids of hepatic cells were also incubated with a lesion-specific repair enzyme (formamidopyrimidine DNA glycosylase – FPG), in order to recognise oxidised purines. Antioxidants were determined in both organs as indicators of pro-oxidant state. In general, both organs displayed an increase in DNA damage for the two Roundup® concentrations and exposure times, although liver showed to be less susceptible to the lower concentration. The enzyme-modified comet assay showed the occurrence of FPG-sensitive sites in liver only after a 3-day exposure to the higher Roundup® concentration. The antioxidant defences were in general unresponsive, despite a single increment of catalase activity in gills (116 μg L−1, 3-day) and a decrease of superoxide dismutase activity in liver (58 μg L−1, 3-day). Overall, the mechanisms involved in Roundup®-induced DNA strand-breaks showed to be similar in both organs. Nevertheless, it was demonstrated that the type of DNA damage varies with the concentration and exposure duration. Hence, after 1-day exposure, an increase on pro-oxidant state is not a necessary condition for the induction of DNA-damaging effects of Roundup®. By increasing the duration of exposure to three days, ROS-dependent processes gained preponderance as a mechanism of DNA-damage induction in the higher concentration.[Guilherme, Gaivão, Santos, Pacheco, (2012). DNA damage in fish (Anguilla anguilla) exposed to a glyphosate-based herbicide – Elucidation of organ-specificity and the role of oxidative stress. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 743(1-2):1-9. doi.org/10.1016/j.mrgentox.2011.10.017] Comment

Techniques to overcome weed issues in organic wheat

Zheljana Peric / WeedsNews3877 / October 18, 2012 / 12:53:35 PM EST / 0 Comments