Environmental Impact of Glyphosate-Resistant Weeds in Canada

Weed Science ◽  
2014 ◽  
Vol 62 (2) ◽  
pp. 385-392 ◽  
Author(s):  
Hugh J. Beckie ◽  
Peter H. Sikkema ◽  
Nader Soltani ◽  
Robert E. Blackshaw ◽  
Eric N. Johnson
Keyword(s):  
Environmental Impact ◽  
Weed Control ◽  
Acetolactate Synthase ◽  
Application Rate ◽  
Weed Species ◽  
Common Ragweed ◽  
Herbicide Resistant ◽  
Herbicide Treatments ◽  
Relative Potential ◽  
Synthase Inhibitor

Glyphosate-resistant (GR) giant ragweed, horseweed, and common ragweed were confirmed in southwestern Ontario, Canada in 2008, 2010, and 2011, respectively. In the western prairie provinces of Alberta and Saskatchewan, GR (plus acetolactate synthase inhibitor-resistant) kochia was discovered in 2011. This symposium paper estimates the environmental impact (EI) of the top herbicide treatments or programs used to manage these GR weed species in the major field crops grown in each region. For each herbicide treatment, EI (per ha basis) was calculated as the environmental impact quotient (EIQ), which quantifies the relative potential risk of pesticide active ingredients on human and ecological health based on risk components to farm workers, consumers, and the environment, multiplied by the application rate (kg ai ha−1). Total EI is defined as EI (per ha basis) multiplied by the application area (i.e., land area affected by a GR weed). It was assumed that all herbicide treatments would supplement the continued usage of glyphosate because of its broad spectrum weed control. For the control of these GR weeds, most treatments contain auxinic or protoporphyrinogen oxidase (PPO)-inhibiting herbicides. The majority of auxinic herbicide treatments result in low (EI ≤ 10) to moderate (11 to 20) EI, whereas all treatments of PPO inhibitors have low EI. Total EI of GR horseweed and kochia will generally be greater than that of giant or common ragweed because of rapid seed dispersal. For recommended herbicide treatments to control GR weeds (and herbicide-resistant weeds in general), EI data should be routinely included with cost and site of action in weed control extension publications and software, so that growers have the information needed to assess the EI of their actions.

Inhibition of Plant Acetolactate Synthase by Nicosulfuron, Rimsulfuron, and Their Mixture DPX-79406

Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 327-332 ◽  
Author(s):  
Mounir Mekki ◽  
Gilles D. Leroux
Keyword(s):  
Binding Site ◽  
Weed Control ◽  
Specific Activity ◽  
Acetolactate Synthase ◽  
Distinct Pattern ◽  
Sulfonylurea Herbicides ◽  
Weed Species ◽  
Common Ragweed ◽  
Proso Millet ◽  
Wild Oats

Nicosulfuron and rimsulfuron are two selective postemergence sulfonylurea herbicides commercialized, respectively, in Europe and USA for weed control in maize. They are under development in Canada as a 1:1 premix (DPX-79406). The objective of the present study was to investigate the effects of these herbicides and their interactions on acetolactate synthase (ALS) activity of selected annual weed species. Each nicosulfuron and rimsulfuron treatment used over a concentration range of 0.01 to 10 μM produced a distinct pattern of ALS inhibition for common ragweed, proso millet, redroot pigweed, smooth crabgrass, and wild oats. Based on ALS specific activity, I50 values for each herbicide differed slightly among the five weed species. However, rimsulfuron was much more inhibitory to ALS than was nicosulfuron. Common ragweed ALS activity increased linearly from 30 to 120 min, even in the continual presence of both herbicides in the assay buffer. This suggests the reversibility of their interaction with ALS. Delaying nicosulfuron (1 μM) or rimsulfuron (0.1 μM) additions to the assay buffer, after initiating the reaction with the enzyme, resulted in a quadratic increase of common ragweed ALS activity. In the continual presence of 0.1 μM of rimsulfuron, addition of 0.1 or 1 μM nicosulfuron did not affect ALS activity any further. However, in the continual presence of 0.1 μM of nicosulfuron, delaying rimsulfuron addition caused an increase in ALS activity. This increase was lower in the presence of 1 μM of nicosulfuron. Inhibition of common ragweed ALS by nicosulfuron and rimsulfuron was not independent of each other, suggesting some competition between the two herbicides for a common binding site on ALS.

Herbicide-resistant weeds in the Canadian prairies: 2012 to 2017

2019 ◽  
Vol 34 (3) ◽  
pp. 461-474
Author(s):  
Hugh J. Beckie ◽  
Scott W. Shirriff ◽  
Julia Y. Leeson ◽  
Linda M. Hall ◽  
K. Neil Harker ◽  
...  
Keyword(s):  
Acetolactate Synthase ◽  
Control Group ◽  
Wild Oat ◽  
Weed Species ◽  
Canadian Prairies ◽  
Herbicide Resistant ◽  
Sample Testing ◽  
Group 2 ◽  
Synthase Inhibitor ◽  
Group 1

AbstractThis 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.

Establishing white clover (Trifolium repens) as a living mulch: weed control and herbicide tolerance

2021 ◽  
pp. 1-28
Author(s):  
Nicholas T. Basinger ◽  
Nicholas S. Hill
Keyword(s):  
Weed Control ◽  
White Clover ◽  
Cover Crops ◽  
Herbicide Tolerance ◽  
Single Application ◽  
Weed Species ◽  
Living Mulch ◽  
Herbicide Resistant ◽  
Research And Education ◽  
Weed Emergence

Abstract With the increasing focus on herbicide-resistant weeds and the lack of introduction of new modes of action, many producers have turned to annual cover crops as a tool for reducing weed populations. Recent studies have suggested that perennial cover crops such as white clover could be used as living mulch. However, white clover is slow to establish and is susceptible to competition from winter weeds. Therefore, the objective of this study was to determine clover tolerance and weed control in established stands of white clover to several herbicides. Studies were conducted in the fall and winter of 2018 to 2019 and 2019 to 2020 at the J. Phil Campbell Research and Education Center in Watkinsville, GA, and the Southeast Georgia Research and Education Center in Midville, GA. POST applications of imazethapyr, bentazon, or flumetsulam at low and high rates, or in combination with 2,4-D and 2,4-DB, were applied when clover reached 2 to 3 trifoliate stage. Six weeks after the initial POST application, a sequential application of bentazon and flumetsulam individually, and combinations of 2,4-D, 2,4-DB, and flumetsulam were applied over designated plots. Clover biomass was similar across all treatments except where it was reduced by sequential applications of 2,4-D + 2,4-DB + flumetsulam in the 2019 to 2020 season indicating that most treatments were safe for use on establishing living mulch clover. A single application of flumetsulam at the low rate or a single application of 2,4-D + 2,4-DB provided the greatest control of all weed species while minimizing clover injury when compared to the non-treated check. These herbicide options allow for control of problematic winter weeds during clover establishment, maximizing clover biomass and limiting canopy gaps that would allow for summer weed emergence.

scholarly journals Efficiency of glyphosate and ammonium glufosinate against common ragweed (Ambrosia artemisiifolia L.) in vineyards

2019 ◽  
pp. 45-50
Author(s):  
A. S. Golubev ◽  
I. P. Borushko ◽  
V. I. Dolzhenko
Keyword(s):  
Quantitative Method ◽  
Application Rate ◽  
Ambrosia Artemisiifolia ◽  
Cabernet Sauvignon ◽  
Weed Species ◽  
Common Ragweed ◽  
Glufosinate Ammonium ◽  
Ammonium Glufosinate ◽  
Effi Ciency ◽  
Krasnodar Region

The use of glyphosate (720-2880 g/h a.i.) and ammonium glufosinate herbicides (375-1500 g/h a.i.) to control of common ragweed (Ambrosia artemisiifolia L.) has been studied in trials (2013-2018) in the vineyards of Rkatsiteli, Liang and Cabernet Sauvignon in Abinsk district of Krasnodar region. Accounting of weeds was done by a quantitative method with counting the number of each weed species in each plot. Counts were performed before the treatment and in 15, 30 and 45 days after spraying. The effi cacy of herbicide was determined in relation to the untreated control and expressed as a percentage. The main evaluation criterion was the eff ectiveness of 100 % in one of the accounts or the average (for all counts) effi ciency of more than 90 %. The results showed that in 95 % of trials spraying of 1440 g/h of glyphosate 1440 g/h of glyphosate (a.i.) and higher ensured processing effi ciency exceeding 90 %. Herbicides such as Roundup, containing 360 g/l of isopropylamine salt, can be recommended for use to control of common ragweed in the application rate 4.0 l/ha. Destruction of all common ragweed observed when using not less than 600 g/h glufosinate ammonium. Thus, Herbicides such as Basta, containing 150 g/l of ammonium glufosinate, to control of common ragweed should be applied by fractional application vegetative weeds (2.5 l/h + 1.5 l/h).

History of Identification of Herbicide-Resistant Weeds

1992 ◽  
Vol 6 (3) ◽  
pp. 615-620 ◽  
Author(s):  
Jodie S. Holt
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Triazine Herbicides ◽  
Mechanisms Of Resistance ◽  
Weed Species ◽  
Crop Species ◽  
Herbicide Resistant ◽  
History Of ◽  
Successful Transfer

At least 57 weed species, including both dicots and monocots, have been reported to have biotypes selected for resistance to the triazine herbicides. In addition, at least 47 species have been reported to have biotypes resistant to one or more of 14 other herbicides or herbicide families. These herbicides include the aryloxyphenoxypropionics, bipyridiliums, dinitroanilines, phenoxys, substituted areas, and sulfonylureas, with two or more resistant biotypes each, as well as several other herbicides in which resistance is less well documented. Although evolved resistance presents a serious problem for chemical weed control, it has also offered new potential for transferring herbicide resistance to crop species. Mechanisms of resistance that are due to single or a few genes have become the focus of biotechnology, as the probability of their successful transfer to crop species is high.

Herbicide resistance in China: a quantitative review

Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 605-612 ◽  
Author(s):  
Xiangying Liu ◽  
Shihai Xiang ◽  
Tao Zong ◽  
Guolan Ma ◽  
Lamei Wu ◽  
...  
Keyword(s):  
Herbicide Resistance ◽  
Crop Production ◽  
Rapid Evolution ◽  
Acetolactate Synthase ◽  
Cross Resistance ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Auxin Herbicides ◽  
Economic Boom ◽  
Meta Analyses

AbstractThe widespread, rapid evolution of herbicide-resistant weeds is a serious and escalating agronomic problem worldwide. During China’s economic boom, the country became one of the most important herbicide producers and consumers in the world, and herbicide resistance has dramatically increased in the past decade and has become a serious threat to agriculture. Here, following an evidence-based PRISMA (preferred reporting items for systematic reviews and meta-analyses) approach, we carried out a systematic review to quantitatively assess herbicide resistance in China. Multiple weed species, including 26, 18, 11, 9, 5, 5, 4, and 3 species in rice (Oryza sativa L.), wheat (Triticum aestivum L.), soybean [Glycine max (L.) Merr.], corn (Zea mays L.), canola (Brassica napus L.), cotton (Gossypium hirsutum L.)., orchards, and peanut (Arachis hypogaea L.) fields, respectively, have developed herbicide resistance. Acetolactate synthase inhibitors, acetyl-CoA carboxylase inhibitors, and synthetic auxin herbicides are the most resistance-prone herbicides and are the most frequently used mechanisms of action, followed by 5-enolpyruvylshikimate-3-phosphate synthase inhibitors and protoporphyrinogen oxidase inhibitors. The lack of alternative herbicides to manage weeds that exhibit cross-resistance or multiple resistance (or both) is an emerging issue and poses one of the greatest threats challenging the crop production and food safety both in China and globally.

Influence of Weed Control Programs in Intensive Cropping Systems

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 762-767 ◽  
Author(s):  
N. C. Glaze ◽  
C. C. Dowler ◽  
A. W. Johnson ◽  
D. R. Sumner
Keyword(s):  
Weed Control ◽  
Cropping Systems ◽  
Weed Species ◽  
Multiple Cropping ◽  
Control Programs ◽  
Yellow Nutsedge ◽  
Herbicide Treatments ◽  
Intensive Cropping ◽  
Main Effects ◽  
Herbicide Programs

Six multiple-cropping systems composed of: a) turnip (Brassica campestrisspp.rapifera), corn (Zea maysL.), and snapbean (Phaseolus vulgarisL.); b) turnip, peanut (Arachis hypogaeaL.), and snapbean; c) turnip, corn, and turnip; d) turnip, peanut, and turnip; e) snapbean, soybean [Glycine max(L.) Merr.], and cabbage (Brassica oleraceaL.); and f) turnip, cucumber (Cucumis sativusL.), cowpea [Vigna unguiculata(L.) Walp.], and turnip were subjected to nematicide and weed control programs of cultivation or herbicides. Herbicide programs were superior to cultivation in control of weeds. Weeds remaining in the row following cultivation competed severely with crops. Weed species remaining were altered depending on the method of control and crop. Yellow nutsedge (Cyperus esculentusL. ♯3CYPES) increased rapidly in all herbicide programs but not in cultivated plots. Pigweeds (Amaranthusspp.) were controlled by herbicides but increased in cultivated plots. Corn, peanut, soybean, and spring snapbean yields were higher in herbicide treatments than in cultivated treatments. Cucumber was the only crop that had increased yields for both main effects, herbicide and nematicide. Turnip was consistently injured in herbicide treatments, which was believed to be caused by residues from previous crops interacting with pathogens and possible allelopathic effects of decaying organic matter.

Tolpyralate Efficacy: Part 2. Comparison of Three Group 27 Herbicides Applied POST for Annual Grass and Broadleaf Weed Control in Corn

2018 ◽  
Vol 32 (6) ◽  
pp. 707-713 ◽  
Author(s):  
Brendan A. Metzger ◽  
Nader Soltani ◽  
Alan J. Raeder ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Effective Dose ◽  
Weed Control ◽  
Biologically Effective Dose ◽  
Annual Grass ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Percentage Points ◽  
Green Foxtail

AbstractTolpyralate is a new Group 27 pyrazolone herbicide that inhibits the 4-hydroxyphenyl-pyruvate dioxygenase enzyme. In a study of the biologically effective dose of tolpyralate from 2015 to 2017 in Ontario, Canada, tolpyralate exhibited efficacy on a broader range of species when co-applied with atrazine; however, there is limited published information on the efficacy of tolpyralate and tolpyralate+atrazine relative to mesotrione and topramezone, applied POST with atrazine at label rates, for control of annual grass and broadleaf weeds. In this study, tolpyralate applied alone at 30 g ai ha−1 provided >90% control of common lambsquarters, velvetleaf, common ragweed, Powell amaranth/redroot pigweed, and green foxtail at 8 weeks after application (WAA). Addition of atrazine was required to achieve >90% control of wild mustard, ladysthumb, and barnyardgrass at 8 WAA. Tolpyralate+atrazine (30+1,000 g ai ha−1) and topramezone+atrazine (12.5+500 g ai ha−1) provided similar control at 8 WAA of the eight weed species in this study; however, tolpyralate+atrazine provided >90% control of green foxtail by 1 WAA. Tolpyralate+atrazine provided 18, 68, and 67 percentage points better control of common ragweed, green foxtail, and barnyardgrass, respectively, than mesotrione+atrazine (100+280 g ai ha−1) at 8 WAA. Overall, tolpyralate+atrazine applied POST provided equivalent or improved control of annual grass and broadleaf weeds compared with mesotrione+atrazine and topramezone+atrazine.

Utility of Clomazone for Annual Grass and Broadleaf Weed Control in Peanut (Arachis hypogaea)

1994 ◽  
Vol 8 (1) ◽  
pp. 23-27 ◽  
Author(s):  
David L. Jordan ◽  
John W. Wilcut ◽  
Leslie D. Fortner
Keyword(s):  
Weed Control ◽  
Arachis Hypogaea ◽  
Field Experiments ◽  
Systems Approach ◽  
Annual Grass ◽  
Weed Species ◽  
Common Ragweed ◽  
Prickly Sida ◽  
Better Than ◽  
Large Crabgrass

Field experiments conducted in 1988 and 1989 evaluated clomazone alone and in a systems approach for weed control in peanut. Clomazone PPI at 0.8 kg ai/ha controlled common ragweed, prickly sida, spurred anoda, and tropic croton better than ethalfluralin and/or metolachlor applied PPI. POST application of acifluorfen plus bentazon was not needed to control these weeds when clomazone was used. Acifluorfen plus bentazon improved control of these weeds when clomazone was not used and generally were necessary to obtain peanut yields regardless of the soil-applied herbicides. Alachlor PRE did not improve clomazone control of any weed species evaluated. Fall panicum and large crabgrass control was similar with clomazone or clomazone plus ethalfluralin.

scholarly journals MANAGEMENT OF RED RICE (ORYZA SATIVA) AND BARNYARDGRASS (ECHINOCHLOA CRUS-GALLI) GROWN WITH SORGHUM WITH REDUCED RATE OF ATRAZINE AND MECHANICAL METHODS

2012 ◽  
Vol 48 (4) ◽  
pp. 587-596 ◽  
Author(s):  
ANDRÉ ANDRES ◽  
GERMANI CONCENÇO ◽  
GIOVANI THEISEN ◽  
LEANDRO GALON ◽  
FRANCO TESIO
Keyword(s):  
Oryza Sativa ◽  
Weed Control ◽  
Control Method ◽  
Application Rate ◽  
Soil Tillage ◽  
Weedy Rice ◽  
Red Rice ◽  
Weed Species ◽  
Mechanical Methods ◽  
Tillage System

SUMMARYThe weedy variety ofOryza sativaoccurs in several rice cultivation areas reducing both grain yield and quality. Prevention and crop rotation are considered the basic means to reduce its presence. Weed control in sorghum is generally attained with atrazine. In this study, the efficacy of both chemical and mechanical methods for control, under different soil tillage conditions, of weedy rice and barnyardgrass during sorghum cultivation was evaluated with the aim to reduce the application rate of atrazine. In the case of chemical control, the atrazine rate (1000, 1500, 2000, 2500 and 3000 ga.i.ha−1) and application timing (pre- and post-emergence) were assessed. With the mechanical control method, the number of interventions (inter-row hoeing with sorghum at 3, 4–5 and 6–8 leaves) to avoid weed competition was determined. The effect of the tillage system on weed population was investigated comparing conventional (ploughing), minimum-tillage (disc harrowing) and sod seeding (no-tillage) in combination with pre- and post-emergence herbicide treatments. The results showed that efficient control of weedy rice and barnyardgrass was achieved in lowlands with sorghum in rotation with rice. Both chemical and mechanical methods of weed control in sorghum gave a level of efficiency higher than 60%. The application of atrazine was more efficient in pre-emergence application, rather than in post-emergence treatments, in all soil tillage systems tested. On both weed species, the most suitable application rate was the pre-emergence treatment with 1500 ga.i.ha−1, and the adoption of higher rates did not significantly increase the herbicidal efficacy. The adoption of two or three mechanical interventions resulted in sorghum yield higher than the chemical post-emergence application, and similar to the application of atrazine in pre-emergence. Higher yield results were in accordance to greater weed control, being obtained in the conventional tillage system.

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