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Hugh J. Beckie - One of the best experts on this subject based on the ideXlab platform.
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Herbicide-Resistant Weeds in the Canadian prairies: 2012 to 2017
Weed Technology, 2019Co-Authors: Hugh J. Beckie, Scott W. Shirriff, Julia Y. Leeson, Linda M. Hall, K. Neil Harker, Faye Dokken-bouchard, Clark A. BrenzilAbstract:This report updates the incidence of Herbicide-Resistant (HR) Weeds across western Canada from the last report covering 2007 to 2011. This third round of preharvest surveys was conducted in Saskatchewan in 2014 and 2015, Manitoba in 2016, and Alberta in 2017, totaling 798 randomly selected cropped fields across 28 million ha. In addition, we screened 1,108 weed seed samples submitted by prairie growers or industry between 2012 and 2016. Of 578 fields where wild oat seed was collected, 398 (69%) had an HR biotype: 62% acetyl-CoA carboxylase inhibitor (WSSA Group 1) resistant, 34% acetolactate synthase inhibitor (Group 2) resistant, and 27% Group 1+2 resistant (vs. 41%, 12%, and 8%, respectively, in the previous second-round surveys from 2007 to 2009). The sharp increase in Group 2 resistance is the result of reliance on this site of action to manage Group 1 resistance and the resultant increased selection pressure. There are no POST options to control Group 1+2–HR wild oat in wheat or barley. The rise of Group 2 resistance in green foxtail (11% of sampled fields) and yellow foxtail (17% of Manitoba fields), which was not detected in the previous survey round, parallels the results for wild oat resistance. Various Group 2–HR populations of broadleaf Weeds were confirmed, with cleavers and field pennycress being most abundant. Results of submission-sample testing reflected survey results. Although not included in this study, a postharvest survey in Alberta in 2017 indicated widespread Groups 2, 4 (dicamba), and 9 (glyphosate) resistance in kochia and Group 2 resistance in Russian thistle. These surveys bring greater awareness of HR Weeds to growers and land managers at local and regional levels, and highlight the urgency to preserve herbicide susceptibility in our key economic weed species.Nomenclature: Acetolactate synthase inhibitor; acetyl-CoA carboxylase inhibitor; dicamba; glyphosate; Cleavers, Galium spp.; field pennycress, Thlaspi arvense L.; green foxtail, Setaria viridis (L.) P. Beauv.; kochia, Bassia scoparia (L.) A. J. Scott; Russian thistle, Salsola tragus L.; wild oat, Avena fatua L.; yellow foxtail, Setaria pumila (Poir.) Roem. & Schult
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efficacy of fall and spring applied pyroxasulfone for herbicide resistant Weeds in field pea
Weed Technology, 2014Co-Authors: Breanne D Tidemann, Hugh J. Beckie, Linda M. Hall, Eric N Johnson, Ken L Sapsford, Lisa L RaatzAbstract:Abstract Field trials were initiated in fall 2011 to determine the potential of pyroxasulfone to control acetolactate synthase (ALS) inhibitor-resistant Weeds in field pea. Pyroxasulfone was applied in split-plot trials at five locations in western Canada using fall and PRE spring applications of 0 to 400 g ai ha−1. Trial locations were chosen with a range of soil organic matter content: 2.9, 4.3, 5.5, 10.5, and 10.6% at Scott, Kernen, Kinsella, Melfort, and Ellerslie, respectively. The herbicide dose required to reduce biomass by 50% (ED50) in false cleavers ranged between 53 and 395 g ha−1 at Scott and Ellerslie, respectively. Wild oat ED50s varied between 0.54 g ha−1 at Scott in the fall and 410 g ai ha−1 in the spring at Melfort. ED50s for wild oat and false cleavers varied by 7.4- and 746-fold, respectively, depending primarily on the organic matter content at the trial location. The effect of application timing was not consistent. Significant yield reductions and pea injury occurred at 150 and 100 g...
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Herbicide-Resistant Weeds: from research and knowledge to future needs
Evolutionary applications, 2013Co-Authors: Roberto Busi, Hugh J. Beckie, Martin M. Vila-aiub, Todd A. Gaines, Danica E. Goggin, Shiv S. Kaundun, Myrtille Lacoste, Paul Neve, Scott J. Nissen, Jason K. NorsworthyAbstract:Synthetic herbicides have been used globally to control Weeds in major field crops. This has imposed a strong selection for any trait that enables plant populations to survive and reproduce in the presence of the herbicide. Herbicide resistance in Weeds must be minimized because it is a major limiting factor to food security in global agriculture. This represents a huge challenge that will require great research efforts to develop control strategies as alternatives to the dominant and almost exclusive practice of weed control by herbicides. Weed scientists, plant ecologists and evolutionary biologists should join forces and work towards an improved and more integrated understanding of resistance across all scales. This approach will likely facilitate the design of innovative solutions to the global herbicide resistance challenge.
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Herbicide-Resistant Weeds in the Canadian Prairies: 2007 to 2011
Weed Technology, 2013Co-Authors: Hugh J. Beckie, Scott W. Shirriff, Chris Lozinski, Clark A. BrenzilAbstract:Abstract A late-summer survey of Herbicide-Resistant (HR) Weeds was conducted in Alberta in 2007, Manitoba in 2008, and Saskatchewan in 2009, totaling 1,000 randomly selected annually cropped fields. In addition, we screened 1,091 weed seed samples (each sample from one field) submitted by Prairie growers between 2007 and 2011. Of 677 fields where wild oat samples were collected, 298 (44%) had an HR biotype. Group 1 (acetyl CoA carboxylase inhibitor)-HR wild oat was confirmed in 275 fields (41%), up from 15% in previous baseline surveys (2001 to 2003). Group 2 (acetolactate synthase)-HR wild oat was found in 12% of fields (vs. 8% in 2001 to 2003). Group 8 (triallate, difenzoquat)-HR wild oat was identified in only 8% of fields (not tested in 2001 to 2003); the frequency of occurrence of group 1+2-HR wild oat was similar (8%, vs. 3% in 2001 to 2003). Group 1-HR green foxtail was found in 27% of 209 fields sampled for the weed (vs. 6% in 2001 to 2003). Group 2-HR spiny sowthistle was confirmed in all Albert...
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Herbicide-Resistant Weeds: Management Tactics and Practices1
Weed Technology, 2006Co-Authors: Hugh J. BeckieAbstract:In input-intensive cropping systems around the world, farmers rarely proactively manage Weeds to prevent or delay the selection for herbicide resistance. Farmers usually increase the adoption of integrated weed management practices only after herbicide resistance has evolved, although herbicides continue to be the dominant method of weed control. Intergroup herbicide resistance in various weed species has been the main impetus for changes in management practices and adoption of cropping systems that reduce selection for resistance. The effectiveness and adoption of herbicide and nonherbicide tactics and practices for the proactive and reactive management of Herbicide-Resistant (HR) Weeds are reviewed. Herbicide tactics include sequences and rotations, mixtures, application rates, site-specific application, and use of HR crops. Nonherbicide weed-management practices or nonselective herbicides applied preplant or in crop, integrated with less-frequent selective herbicide use in diversified cropping systems,...
Jason K. Norsworthy - One of the best experts on this subject based on the ideXlab platform.
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A Midsouthern Consultant’s Survey on Weed Management Practices in Soybean
Weed Technology, 2017Co-Authors: Lauren M. Schwartz-lazaro, Jason K. Norsworthy, Lawrence E. Steckel, Daniel O. Stephenson, Mandy D. Bish, Kevin W. Bradley, Jason A. BondAbstract:Soybean consultants from Arkansas, Louisiana, southeast Missouri, Mississippi, and Tennessee were surveyed in 2016 to assess weed management practices and the prevalence of Herbicide-Resistant Weeds in midsouthern U.S. soybean production. The consultants surveyed represented 13%, 28%, 8%, 16%, and 5% of the total soybean area planted in Arkansas, Louisiana, southeast Missouri, Mississippi, and Tennessee, respectively. Of the total scouted area, 78% of the consultants said their growers planted glyphosate-resistant soybean in 2016, with 18% planting glufosinate-resistant (LibertyLink®), primarily due to familiarity with and cost of the technology. Although 94% of the consultants determined that glufosinate was most effective on killing Palmer amaranth, the primary concern associated with controlling Herbicide-Resistant Weeds was the associated cost, followed by return profit and time constraints. Palmer amaranth, morningglory species, horseweed, barnyardgrass, and Italian ryegrass were the five most problematic Weeds in soybean across the five states. Palmer amaranth was the most problematic and important weed in each state individually. The increased concern (77% of consultants) with this species was attributed to the rising concern with and occurrence of protoporphyrinogen oxidase-resistant Palmer amaranth. Consultants were of the opinion that more research was needed on cover crops and the new traited technologies in order to improve weed management in soybean.Nomenclature: Glufosinate; glyphosate; barnyardgrass, Echinochloa crus-galli (L.) Beauv.; horseweed, Conyza canadensis (L.) Cronq.; Italian ryegrass, Lolium perenne L. ssp. multiflorum (Lam.) Husnot; morningglory, Ipomoea spp.; Palmer amaranth, Amaranthus palmeri S. Wats.; soybean, Glycine max (L.) Merr.
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Herbicide-Resistant Weeds: from research and knowledge to future needs
Evolutionary applications, 2013Co-Authors: Roberto Busi, Hugh J. Beckie, Martin M. Vila-aiub, Todd A. Gaines, Danica E. Goggin, Shiv S. Kaundun, Myrtille Lacoste, Paul Neve, Scott J. Nissen, Jason K. NorsworthyAbstract:Synthetic herbicides have been used globally to control Weeds in major field crops. This has imposed a strong selection for any trait that enables plant populations to survive and reproduce in the presence of the herbicide. Herbicide resistance in Weeds must be minimized because it is a major limiting factor to food security in global agriculture. This represents a huge challenge that will require great research efforts to develop control strategies as alternatives to the dominant and almost exclusive practice of weed control by herbicides. Weed scientists, plant ecologists and evolutionary biologists should join forces and work towards an improved and more integrated understanding of resistance across all scales. This approach will likely facilitate the design of innovative solutions to the global herbicide resistance challenge.
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Adoption of Best Management Practices for Herbicide-Resistant Weeds in Midsouthern United States Cotton, Rice, and Soybean
Weed Technology, 2013Co-Authors: Dilpreet S. Riar, Jason K. Norsworthy, Lawrence E. Steckel, Daniel O. Stephenson, Thomas W. Eubank, Jason A. Bond, Robert C. ScottAbstract:Abstract In fall 2011, cotton and soybean consultants from Arkansas, Louisiana, Mississippi, and Tennessee were surveyed through direct mail and on-farm visits, and rice consultants from Arkansas and Mississippi were surveyed through direct mail to assess the importance and level of implementation of herbicide resistance best management practices (HR-BMPs) for Herbicide-Resistant Weeds. Proper herbicide timing, clean start with no Weeds at planting, application of multiple effective herbicide modes of action, use of full labeled herbicide rates, and prevention of crop weed seed production with importance rating of ≥ 4.6 out of 5.0 were perceived as the most important HR-BMPs in all crops. Purchase of certified rice seed was on 90% of scouted hectares. In contrast, least important HR-BMPs as perceived by consultants with importance ratings of ≤ 4.0 in cotton, ≤ 3.7 in rice, and ≤ 3.8 in soybean were cultural practices such as manual removal of Weeds; tillage including disking, cultivation, or deep tillage;...
Ian Heap - One of the best experts on this subject based on the ideXlab platform.
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Herbicide Resistant Weeds
Integrated Pest Management, 2014Co-Authors: Ian HeapAbstract:The International Survey of Herbicide-Resistant Weeds (www.Weedscience.org) reports 388 unique cases (species x site of action) of Herbicide-Resistant Weeds globally, with 210 species. Weeds have evolved resistance to 21 of the 25 known herbicide sites of action and to 152 different herbicides. The ALS inhibitors (126 resistant species) are most prone to resistance, followed by the triazines (69 species), and the ACCase inhibitors (42 species). Herbicide-Resistant Weeds first became problematic in the USA and Europe in the 1970s and early 1980s due to the repeated applications of atrazine and simazine in maize crops. Growers turned to the ALS and ACCase inhibitor herbicides in the 1980s and 1990s to control triazine-resistant Weeds and then to glyphosate-resistant crops in the mid 1990s in part to control ALS inhibitor, ACCase inhibitor, and triazine-resistant Weeds. The massive area treated with glyphosate alone in glyphosate-resistant crops has led to a rapid increase in the evolution of glyphosate-resistant Weeds. Glyphosate-resistant Weeds are found in 23 species and 18 countries and they now dominate herbicide-resistance research, but have not yet surpassed the economic damage caused by ALS inhibitor and ACCase inhibitor resistant Weeds. Lolium rigidum remains the world’s worst Herbicide-Resistant weed (12 countries, 11 sites of action, 9 cropping regimes, over 2 million hectares) followed by Amaranthus palmeri, Conyza canadensis, Avena fatua, Amaranthus tuberculatus, and Echinochloa crus-galli. In the years ahead multiple-resistance in Weeds combined with the decline in the discovery of novel herbicide modes of action present the greatest threat to sustained weed control in agronomic crops. The discovery of new herbicide sites of action and new Herbicide-Resistant crop traits will play a major role in weed control in the future however growers must make the transition to integrated weed management that utilizes all economically available weed control techniques.
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Global perspective of Herbicide-Resistant Weeds.
Pest management science, 2014Co-Authors: Ian HeapAbstract:Two hundred and twenty weed species have evolved resistance to one or more herbicides, and there are now 404 unique cases (species × site of action) of Herbicide-Resistant Weeds globally. ALS inhibitor-resistant Weeds account for about a third of all cases (133/404) and are particularly troublesome in rice and cereals. Although 71 weed species have been identified with triazine resistance, their importance has dwindled with the shift towards Roundup Ready® crops in the USA and the reduction of triazine usage in Europe. Forty-three grasses have evolved resistance to ACCase inhibitors, with the most serious cases being Avena spp., Lolium spp., Phalaris spp., Setaria spp. and Alopecurus myosuroides, infesting more than 25 million hectares of cereal production globally. Of the 24 weed species with glyphosate resistance, 16 have been found in Roundup Ready® cropping systems. Although Conyza canadensis is the most widespread glyphosate-resistant weed, Amaranthus palmeri and Amaranthus tuberculartus are the two most economically important glyphosate-resistant Weeds because of the area they infest and the fact that these species have evolved resistance to numerous other herbicide sites of action, leaving growers with few herbicidal options for their control. The agricultural chemical industry has not brought any new herbicides with novel sites of action to market in over 30 years, making growers reliant on using existing herbicides in new ways. In addition, tougher registration and environmental regulations on herbicides have resulted in a loss of some herbicides, particularly in Europe. The lack of novel herbicide chemistries being brought to market combined with the rapid increase in multiple resistance in Weeds threatens crop production worldwide. © 2013 Society of Chemical Industry
Roland Gerhards - One of the best experts on this subject based on the ideXlab platform.
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A Fluorescence Sensor Capable of Real-Time Herbicide Effect Monitoring in Greenhouses and the Field.
Sensors, 2018Co-Authors: Pei Wang, Weidong Jia, Yin Chen, Roland GerhardsAbstract:Herbicide resistant Weeds need to be identified early so that yield loss can be avoided by applying proper field management strategies. A novel chlorophyll-fluorescence-imaging sensor has been developed to conduct real-time herbicide effect evaluation. In this research, greenhouse and field experiments were conducted to calibrate the capability of the sensor in monitoring herbicide effects on different biotypes of two grass Weeds (Alopecurus myosuroides, Apera spica-venti) in southwestern Germany. Herbicides with different modes of action were applied for the effect monitoring. Chlorophyll fluorescence yield of the plants was measured 3⁻15 days after treatment (DAT) using the new fluorescence sensor. Visual assessment of the Weeds was carried out on 21 DAT. The results showed that the maximal PS II quantum yield (Fv/Fm) of herbicide sensitive Weeds was significantly lower than the values of resistant populations in 5 DAT. The new technology was capable of quickly identifying the herbicide's effect on plants. It can be used to optimize management strategies to control herbicide resistant Weeds.
Norman C. Ellstrand - One of the best experts on this subject based on the ideXlab platform.
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Taxonomic and Life History Bias in Herbicide Resistant Weeds: Implications for Deployment of Resistant Crops
PloS one, 2013Co-Authors: Jodie S. Holt, Ian M. Heap, Shana R. Welles, Katia Silvera, Sylvia M. Heredia, Alejandra Martínez-berdeja, Kai T. Palenscar, Lynn C. Sweet, Norman C. EllstrandAbstract:Evolved herbicide resistance (EHR) is an important agronomic problem and consequently a food security problem, as it jeopardizes herbicide effectiveness and increases the difficulty and cost of weed management. EHR in Weeds was first reported in 1970 and the number of cases has accelerated dramatically over the last two decades. Despite 40 years of research on EHR, why some Weeds evolve resistance and others do not is poorly understood. Here we ask whether weed species that have EHR are different from Weeds in general. Comparing taxonomic and life history traits of Weeds with EHR to a control group (“the world's worst Weeds”), we found Weeds with EHR significantly over-represented in certain plant families and having certain life history biases. In particular, resistance is overrepresented in Amaranthaceae, Brassicaceae and Poaceae relative to all Weeds, and annuality is ca. 1.5 times as frequent in Weeds with EHR as in the control group. Also, for perennial EHR Weeds, vegetative reproduction is only 60% as frequent as in the control group. We found the same trends for subsets of Weeds with EHR to acetolactate synthase (ALS), photosystem II (PSII), and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase-inhibitor herbicides and with multiple resistance. As herbicide resistant crops (transgenic or not) are increasingly deployed in developing countries, the problems of EHR could increase in those countries as it has in the USA if the selecting herbicides are heavily applied and appropriate management strategies are not employed. Given our analysis, we make some predictions about additional species that might evolve resistance.