Nature, Occurrence, and Cost of Herbicide-Resistant Wild Oat (Avena fatua) in Small-Grain Production Areas

Surveys were conducted across the northern Great Plains of Canada in 1996 and 1997 to determine the nature and occurrence of herbicide-resistant (HR) biotypes of wild oat (Avena fatua). The surveys indicated that resistance to acetyl-CoA carboxylase (ACCase) inhibitors (Group 1) occurred most frequently relative to other herbicide groups. Group 1-HR wild oat occurred in over one-half of fields surveyed in each of the three prairie provinces. Of particular concern was the relatively high incidence of multiple-group resistance in wild oat in Saskatchewan and Manitoba. In Saskatchewan, 18% of Group 1-HR populations were also resistant to acetolactate synthase inhibitors (imidazolinones), even though these herbicides were not frequently used. In Manitoba, 27% of fields surveyed had wild oat resistant to herbicides from more than one group. Four populations were resistant to all herbicides registered for use in wheat (Triticum aestivum). Depending on the nature of resistance in wild oat, alternative herbicides available for their control may substantially increase costs to the grower. The cost to growers of managing HR wild oat in Saskatchewan and Manitoba using alternative herbicides is estimated at over $4 million annually. For some HR biotypes, alternative herbicides either are not available or all have the same site of action, which restricts crop or herbicide rotation options and threatens the future sustainability of small-grain annual cropping systems where these infestations occur.

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Survey of herbicide-resistant wild oat (Avena fatua) in two townships in Saskatchewan

Canadian Journal of Plant Science ◽

10.4141/p01-067 ◽

2002 ◽

Vol 82 (2) ◽

pp. 463-471 ◽

Cited By ~ 22

Author(s):

H. J. Beckie ◽

A. G. Thomas ◽

F. C. Stevenson

Keyword(s):

Herbicide Resistance ◽

Acetolactate Synthase ◽

Avena Fatua ◽

Farm Size ◽

Wild Oat ◽

Multiple Group ◽

Group 2 ◽

Als Inhibitors ◽

Group Resistance ◽

Group 1

The nature and occurrence of herbicide resistance in wild oat in annual crops grown in the Grassland and Parkland regions of Saskatchewan were determined in a systematic survey of fields in two townships in 1997. The survey found that over one-half of fields in both townships had populations resistant to Group 1 [acetyl-CoA carboxylase (ACCase) inhibitors], Group 2 [acetolactate synthase (ALS) inhibitors], and/or Group 8 (e.g., triallate, difenzoquat) herbicides. Forty-three percent of fields in the Grassland township and 48% of fields in the Parkland township had Group 1-resistant (HR) wild oat; 30 and 17% of fields in the Grassland and Parkland township, respectively, had populations exhibiting Group 2 resistance, whereas about 15% of fields in both townships had Group 8-HR wild oat. Single- (Groups 1, 2, or 8) and multiple-group resistance (1, 2; 1, 8; 2, 8; 1, 2, 8) were exhibited in populations in fields in both townships. Frequency of occurrence of resistance was not generally affected by farm size. The nature of resistance in wild oat populations is more diverse, differences in distribution and abundance of HR wild oat biotypes between Grassland and Parkland regions are generally less apparent, and occurrence of resistance is more prevalent than documented previously. Key words: Avena fatua, herbicide resistance, survey

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Herbicide-Resistant Weeds in the Canadian Prairies: 2007 to 2011

Weed Technology ◽

10.1614/wt-d-12-00095.1 ◽

2013 ◽

Vol 27 (1) ◽

pp. 171-183 ◽

Cited By ~ 31

Author(s):

Hugh J. Beckie ◽

Chris Lozinski ◽

Scott Shirriff ◽

Clark. A. Brenzil

Keyword(s):

Acetolactate Synthase ◽

Fold Increase ◽

Wild Oat ◽

Total Field ◽

Herbicide Resistant ◽

Wild Mustard ◽

Green Foxtail ◽

Group 2 ◽

Field Area ◽

Group 1

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 Alberta fields sampled (vs. 67% in 2001); common chickweed was found mainly in Alberta in 40% of fields (vs. 17% in 2001). Group 2-HR weed biotypes not previously detected in the baseline surveys included false cleavers mainly in Alberta (17% of fields) and Saskatchewan (21%), Powell amaranth in Manitoba (16% of fields), wild mustard (three populations in Saskatchewan and Manitoba), and wild buckwheat (one population in Alberta). No sampled weed populations across the Prairies were found to be resistant to herbicides from group 4 (synthetic auxins), group 9 (glyphosate), or group 10 (glufosinate). Based on the proportion of total field area at each site infested with HR weeds, it is estimated that 7.7 million ha (29% of annually cropped land) are infested with HR weeds (eight-fold increase from 2001 to 2003), in a total field area of 9.9 million ha (37%)—over a two-fold increase. Of 816 cases of HR wild oat identified from submitted samples, 69% were group 1-HR, 15% group 2-HR, and 16% group 1+2-HR. Additionally, there were 10 populations of group 1-HR green foxtail in Saskatchewan or Manitoba, and six populations of group 1-HR Persian darnel in southern Alberta and Saskatchewan. Various group 2-HR broadleaf weeds were identified, including 17 wild mustard populations mainly from Saskatchewan and 39 cleavers populations across the three Prairie provinces. Herbicide-use data from 2006 to 2010 indicated continued reliance on group 1 herbicides in cereal crops and group 2 herbicides in pulse crops.

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Interference and management of herbicide-resistant crop volunteers

Weed Science ◽

10.1017/wsc.2021.3 ◽

2021 ◽

pp. 1-69

Author(s):

Amit J. Jhala ◽

Hugh J. Beckie ◽

Thomas J. Peters ◽

A. Stanley Culpepper ◽

Jason K. Norsworthy

Keyword(s):

Great Plains ◽

Management Practices ◽

Yield Loss ◽

Cropping Systems ◽

Northern Great Plains ◽

High Fecundity ◽

Record Keeping ◽

Herbicide Resistant ◽

Seed Loss ◽

The Impact

Abstract Since the commercialization of herbicide-resistant (HR) crops, primarily glyphosate-resistant (GR) crops, their adoption increased rapidly. Multiple HR traits in crops such as canola (Brassica napus L.), corn (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean [Glycine max (L.) Merr.] are available in recent years, and management of their volunteers need attention to prevent interference and yield loss in rotational crops. The objectives of this review were to summarize HR crop traits in barley (Hordeum vulgare L.), canola, corn, cotton, rice (Oryza sativa L.), soybean, sugarbeet (Beta vulgaris L.), and wheat (Triticum aestivum L.); assess their potential for volunteerism; and review existing literature on the interference of HR crop volunteers, yield loss, and their management in rotational crops. Herbicide-resistant crop volunteers are problem weeds in agronomic cropping systems, and the impact of volunteerism depends on several factors such as crop grown in rotation, the density of volunteers, management practices, and micro-climate. Interference of imidazolinone-resistant (IR) barley or wheat volunteers can be a problem in rotational crops, particularly when IR crops such as canola or wheat are grown. Herbicide-resistant canola volunteers are abundant in the Northern Great Plains due to high fecundity, seed loss before or during harvest, secondary seed dormancy, and can interfere in crops grown in rotation such as flax (Linum usitatissimum L.), field peas (Pisum sativum L.), and soybean. Herbicide-resistant corn volunteers are competitive in crops grown in rotation such as corn, cotton, soybean, and sugarbeet, with yield loss depending on the density of HR corn volunteers. Volunteers of HR cotton, rice, soybean, and sugarbeet are not major concerns and can be controlled with existing herbicides. Herbicide options would be limited if the crop volunteers are multiple HR; therefore, a record-keeping of cultivar planted the previous year and selecting herbicide is important. The increasing use of 2,4-D, dicamba, glufosinate, and glyphosate in North American cropping systems requires research on herbicide interactions and alternative herbicides or methods for controlling multiple HR crop volunteers.

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

Weed Technology ◽

10.1017/wet.2019.128 ◽

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.

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Weed Resistance Monitoring in the Canadian Prairies

Weed Technology ◽

10.1614/wt-07-175.1 ◽

2008 ◽

Vol 22 (3) ◽

pp. 530-543 ◽

Cited By ~ 27

Author(s):

Hugh J. Beckie ◽

Julia Y. Leeson ◽

A. Gordon Thomas ◽

Clark A. Brenzil ◽

Linda M. Hall ◽

...

Keyword(s):

Acetolactate Synthase ◽

Resistance Testing ◽

Cross Resistance ◽

Northern Great Plains ◽

Wild Oat ◽

Resistance Monitoring ◽

Green Foxtail ◽

Group 2 ◽

Weed Resistance ◽

Group 1

Weed resistance monitoring has been routinely conducted in the Northern Great Plains of Canada (Prairies) since the mid-1990s. Most recently, random surveys were conducted in Alberta in 2001, Manitoba in 2002, and Saskatchewan in 2003 totaling nearly 800 fields. In addition, nearly 1,300 weed seed samples were submitted by growers across the Prairies between 1996 and 2006 for resistance testing. Collected or submitted samples were screened for group 1 [acetyl-CoA carboxylase (ACCase) inhibitor] and/or group 2 [acetolactate synthase (ALS) inhibitor] resistance. Twenty percent of 565 sampled fields had an herbicide-resistant (HR) wild oat biotype. Most populations exhibited broad cross-resistance across various classes of group 1 or group 2 herbicides. In Manitoba, 22% of 59 fields had group 1–HR green foxtail. Group 2–HR biotypes of kochia were documented in Saskatchewan, common chickweed and spiny sowthistle in Alberta, and green foxtail and redroot pigweed in Manitoba. Across the Prairies, HR weeds are estimated to occur in fields covering an area of nearly 5 million ha. Of 1,067 wild oat seed samples submitted by growers and industry for testing between 1996 and 2006, 725 were group 1 HR, 34 group 2 HR, and 55 groups 1 and 2 HR. Of 80 submitted green foxtail samples, 26 were confirmed group 1 HR; most populations originated from southern Manitoba where the weed is most abundant. Similar to the field surveys, various group 2–HR biotypes were confirmed among submitted samples: kochia, wild mustard, field pennycress,Galiumspp., common chickweed, and common hempnettle. Information from grower questionnaires indicates patterns of herbicide usage are related to location, changing with cropping system. Two herbicide modes of action most prone to select resistance, groups 1 and 2, continue to be widely and repeatedly used. There is little evidence that growers are aware of the level of resistance within their fields, but a majority have adopted herbicide rotations to proactively or reactively manage HR weeds.

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Dynamic Cropping Systems for Sustainable Crop Production in the Northern Great Plains

Agronomy Journal ◽

10.2134/agronj2006.0132 ◽

2007 ◽

Vol 99 (4) ◽

pp. 904-911 ◽

Cited By ~ 1

Author(s):

D. L. Tanaka ◽

J. M. Krupinsky ◽

S. D. Merrill ◽

M. A. Liebig ◽

J. D. Hanson

Keyword(s):

Great Plains ◽

Crop Production ◽

Cropping Systems ◽

Northern Great Plains ◽

Sustainable Crop Production

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Rearing the wheat stem sawfly on an artificial diet

The Canadian Entomologist ◽

10.4039/n04-100 ◽

2005 ◽

Vol 137 (4) ◽

pp. 497-500 ◽

Cited By ~ 2

Author(s):

Tuilo B. Macedo ◽

Paula A. Macedo ◽

Robert K.D. Peterson ◽

David K. Weaver ◽

Wendell L. Morrill

Keyword(s):

Great Plains ◽

Cropping Systems ◽

Insect Pest ◽

The United States ◽

Northern Great Plains ◽

Yield Losses ◽

Canadian Prairies ◽

Wheat Stem Sawfly ◽

Head Weight ◽

Harvest Efficiency

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is an insect pest in dryland wheat cropping systems in the southern Canadian Prairies and the northern Great Plains of the United States (Morrill 1997). Yield losses caused by C. cinctus are due to reduced head weight (Holmes 1977; Morrill et al. 1992) and lodging, which decreases harvest efficiency. Estimates of yield losses in Montana alone are about US$25 million per year.

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An economic comparison of alternative and traditional cropping systems in the northern Great Plains, USA

Renewable Agriculture and Food Systems ◽

10.1079/raf2005128 ◽

2006 ◽

Vol 21 (1) ◽

pp. 68-73 ◽

Cited By ~ 8

Author(s):

Eric A. DeVuyst ◽

Thomas Foissey ◽

George O. Kegode

Keyword(s):

North Dakota ◽

Great Plains ◽

Cropping Systems ◽

Cropping System ◽

Conventional Tillage ◽

Northern Great Plains ◽

Yield Data ◽

Government Program ◽

Current Production ◽

Commodity Programs

AbstractCurrent production practices in the Red River Valley of North Dakota and Minnesota involve use of extensive tillage and/or herbicides to control weeds. Given the erosion potential, environmental concerns associated with herbicides, and herbicide-resistant weeds, alternative cropping systems that mitigate these problems need to be assessed economically. Furthermore, the role that government commodity programs play in the adoption of more ecologically friendly cropping systems needs to be determined. We evaluated 8 years of yield data (1994–2001) from field plots near Fargo, North Dakota, to compare the economics of two alternative cropping systems, reduced-input (RI) and no-till (NT), to a conventional tillage (CT) cropping system. The RI system relies on a more diverse rotation of soybean (SB), spring wheat (SW), sweet clover (SC) and rye, and uses fewer herbicide and fertilizer inputs than CT or NT. Both NT and CT systems rotate SB and SW. We found that CT returns averaged over $47 ha−1more than NT during the study period. Because SC yield data were not available, the economic competitiveness of RI was calculated using break-even yields and returns for SC. Historical SC yields in Cass County, North Dakota were not statistically different from the break-even yields. However, when government program payments were considered, break-even returns for SC increased by about $15 and $18 ha−1and break-even yields by 0.44 and 0.52 MT ha−1for RI to compare with NT and CT, respectively. These results indicate that CT management offers greater economic return than either RI or NT and that government program payments impede adoption of more environmentally friendly cropping systems in the northern Great Plains.

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Wild Oat (Avena fatua) Infestations and Economic Returns as Influenced by Frequency of Control

Weed Technology ◽

10.1017/s0890037x00032334 ◽

1988 ◽

Vol 2 (4) ◽

pp. 495-498 ◽

Cited By ~ 11

Author(s):

John T. O'Donovan

Keyword(s):

Cropping Systems ◽

Avena Fatua ◽

The Other ◽

Wild Oat ◽

Economic Returns ◽

Wild Oats ◽

Average Return

In continuous wheat or barley or in a canola/barley rotation, wild oat control every year over 4 yr maintained wild oat seedling populations at 3 plants/m2 or less. Failure to control wild oats annually increased wild oat populations (>200 plants/m2 by the fourth year) in continuous wheat dramatically, while in the other two cropping systems, populations increased to only 40 plants/m2 or less by the fourth year. In the continuous wheat and in the canola/barley rotation, wild oat control every year generally provided the best economic returns when prices and costs were averaged over 4 yr; in continuous barley, the average return was better when wild oats was controlled only in the second or third years rather than every year.

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