Biologically-effective-dose of pyraflufen-ethyl/2,4-D, applied preplant alone or mixed with metribuzin on glyphosate-resistant horseweed in soybean

2021 ◽  
pp. 1-20
Author(s):  
David B. Westerveld ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Peter H. Sikkema
Keyword(s):  
Effective Dose ◽  
Field Experiments ◽  
Glyphosate Resistance ◽  
Biologically Effective Dose ◽  
Weed Species ◽  
Visible Injury ◽  
Industry Standards

Abstract Glyphosate resistance in weed species has presented immense challenges for farmers in Ontario. The co-application of burndown plus residual herbicides provides control of glyphosate-resistant (GR) horseweed control in soybean. Pyraflufen-ethyl/2,4-D is a premixed herbicide formulation sold under the tradename Blackhawk®. Five field experiments were conducted over a two-year period (2019, 2020) in fields in southwestern Ontario to ascertain the biologically-effective-dose of pyraflufen-ethyl/2,4-D, applied alone, or mixed with metribuzin, for GR horseweed control when applied pre-plant to soybean. Soybean visible injury for all treatments was <15%. At 8 wk after application (WAA), the calculated doses of pyraflufen-ethyl/2,4-D for 50, 80, and 95% GR horseweed control were 390, 1148, and >2108 g ha−1, respectively. The addition of metribuzin to pyraflufen-ethyl/2,4-D reduced the doses of pyraflufen-ethyl/2,4-D for 50, 80, and 95% GR horseweed control to 19, 46 and 201 g ha−1, respectively. Pyraflufen-ethyl/2,4-D + metribuzin controlled GR horseweed 97% which is comparable to the current industry standards. Based on these results, pyraflufen-ethyl/2,4-D + metribuzin (527 + 400 g ha−1) applied preplant can be used for GR horseweed control in soybean.

Biologically effective dose of bromoxynil applied alone and mixed with metribuzin for the control of glyphosate-resistant horseweed in soybean

2021 ◽  
pp. 1-6
Author(s):  
David B. Westerveld ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Peter H. Sikkema
Keyword(s):  
Photosystem Ii ◽  
Effective Dose ◽  
Weed Control ◽  
Field Experiments ◽  
Biologically Effective Dose ◽  
Soybean Yield ◽  
Industry Standards ◽  
Excellent Control

Abstract Glyphosate-resistant (GR) horseweed was first confirmed in Ontario in 2010. GR horseweed interference can reduce soybean yield by up to 97%. Bromoxynil is a photosystem II–inhibiting herbicide that is primarily used for annual broadleaf weed control in monocot crops. The objective of this study was to determine the biologically effective dose (BED) of bromoxynil applied alone and when mixed with metribuzin applied preplant for control of GR horseweed in soybean in Ontario. Five field experiments were conducted over a 2-yr period (2019–2020) to determine the predicted dose of bromoxynil with or without metribuzin that would control GR horseweed 50%, 80%, and 95%. No soybean injury was observed. The predicted doses of bromoxynil to achieve 50% and 80% control of GR horseweed were 98 and 277 g ai ha−1, respectively, at 8 wk after application (WAA). When mixed with metribuzin (400 g ai ha−1), the predicted doses of bromoxynil for 50%, 80%, and 95% control of GR horseweed were 10, 25, and 54 g ai ha−1, respectively. Bromoxynil (280 g ai ha−1) plus metribuzin (400 g ai ha−1) controlled GR horseweed 97%, a finding that was similar to the industry standards of saflufenacil + metribuzin (99% control) and glyphosate/dicamba + saflufenacil (100% control) at 8 WAA. This study concludes that bromoxynil + metribuzin applied before planting provides excellent control of GR horseweed in soybean.

Efficacy of Tiafenacil Applied Preplant Alone or Mixed with Metribuzin for Glyphosate-Resistant Horseweed Control in Soybean

2021 ◽  
pp. 1-21
Author(s):  
David B. Westerveld ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Peter H. Sikkema
Keyword(s):  
Effective Dose ◽  
Management Strategy ◽  
Field Experiments ◽  
Biologically Effective Dose ◽  
Potential Utility ◽  
Industry Standard ◽  
No Till ◽  
Industry Standards ◽  
Herbicide Treatments ◽  
Chemical Class

Abstract Tiafenacil is a recently developed protoporphyrinogen IX oxidase (PPO)-inhibiting herbicide from the pyrimidinedione chemical class that is proposed for use as a preplant (PP) burndown in soybean. Glyphosate-resistant (GR) horseweed is a troublesome weed often found in no-till systems that can dramatically reduce soybean yield; control in soybean has been variable. Five field experiments were conducted over 2019 and 2020 in commercial soybean fields with GR horseweed to determine the biologically-effective-dose (BED) of tiafenacil and tiafenacil + metribuzin, and to compare their efficacy to currently accepted industry standard herbicide treatments in identity-preserved (IP, non-GMO), GR, and glyphosate/dicamba-resistant (GDR) soybean systems. There was no soybean injury with treatments evaluated. The calculated doses of tiafenacil for 50, 80, and 95% control of GR horseweed control were 21, 147 and >200 g ai ha−1, respectively, at 8 weeks after application (WAA). Lower doses were calculated with the addition of metribuzin (400 g ai ha−1) to tiafenacil for 50 and 80% control, with no dose of tiafenacil + metribuzin providing 95% control. Tiafenacil + metribuzin at 25 + 400 and 50 + 400 g ai ha−1 controlled GR horseweed 88 and 93% , respectively which was similar to the industry standards of saflufenacil + metribuzin (25 + 400 g ai ha−1) and glyphosate/dicamba + saflufenacil (1200/600 + 25 g ai ha−1) that provided 98 to 100% control, respectively at 8 WAA. This study presents the potential utility of tiafenacil + metribuzin as a GR horseweed management strategy in soybean.

scholarly journals Glyphosate Resistance in Perennial Ryegrass (Lolium perenneL.) is Associated with a Fitness Penalty

Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Marcos Yanniccari ◽  
Martín Vila-Aiub ◽  
Carolina Istilart ◽  
Horacio Acciaresi ◽  
Ana M. Castro
Keyword(s):  
Perennial Ryegrass ◽  
Water Availability ◽  
Field Experiments ◽  
Seed Mass ◽  
Selection Effect ◽  
Glyphosate Resistance ◽  
Shoot Biomass ◽  
Seed Number ◽  
Fitness Costs ◽  
Weed Species

The net selection effect of herbicides on herbicide-resistance traits in weeds is conditioned by the fitness benefits and costs associated with resistance alleles. Fitness costs play an important evolutionary role preventing the fixation of adaptive alleles and contributing to the maintenance of genetic polymorphisms within populations. Glyphosate is widely used in world agriculture, which has led to the evolution of widespread glyphosate resistance in many weed species. The fitness of glyphosate-resistant and -susceptible perennial ryegrass plants selected from within a single population were studied in two field experiments conducted during 2011 and 2012 under different soil water availability. Glyphosate-resistant plants showed a reduction in height of 12 and 16%, leaf blade area of 16 and 33%, shoot biomass of 45 and 55%, seed number of 33 and 53%, and total seed mass of 16 and 5% compared to glyphosate-susceptible plants in 2011 and 2012, respectively. The reduction in seed number per plant resulted in a 40% fitness cost associated with the glyphosate-resistance trait in perennial ryegrass. Fitness costs of glyphosate-resistant plants were expressed under both conditions of water availability. These results could be useful for designing management strategies and exploiting the reduced glyphosate-resistant perennial ryegrass fitness in the absence of glyphosate selection.

Tolpyralate Efficacy: Part 1. Biologically Effective Dose of Tolpyralate for Control of Annual Grass and Broadleaf Weeds in Corn

2018 ◽  
Vol 32 (6) ◽  
pp. 698-706 ◽  
Author(s):  
Brendan A. Metzger ◽  
Nader Soltani ◽  
Alan J. Raeder ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Effective Dose ◽  
Weed Management ◽  
Field Studies ◽  
Biologically Effective Dose ◽  
Limited Information ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Low Field ◽  
Green Foxtail

AbstractTolpyralate is a new 4-hydroxyphenyl-pyruvate dioxygenase (HPPD)-inhibiting herbicide for POST weed management in corn; however, there is limited information regarding its efficacy. Six field studies were conducted in Ontario, Canada, over 3 yr (2015 to 2017) to determine the biologically effective dose of tolpyralate for the control of eight annual weed species. Tolpyralate was applied POST at six doses from 3.75 to 120 g ai ha−1and tank mixed at a 1:33.3 ratio with atrazine at six doses from 125 to 4,000 g ha−1. Regression analysis was performed to determine the effective dose (ED) of tolpyralate, and tolpyralate+atrazine, required to achieve 50%, 80%, or 90% control of eight weed species at 1, 2, 4, and 8 wk after application (WAA). The ED of tolpyralate for 90% control (ED90) of velvetleaf, common lambsquarters, common ragweed, redroot pigweed or Powell amaranth, and green foxtail at 8 WAA was ≤15.5 g ha−1; however, tolpyralate alone did not provide 90% control of wild mustard, barnyardgrass, or ladysthumb at 8 WAA at any dose evaluated in this study. In contrast, the ED90for all species in this study with tolpyralate+atrazine was ≤13.1+436 g ha−1, indicating that tolpyralate+atrazine can be highly efficacious at low field doses.

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.

scholarly journals Weed Control in White Bean with Pethoxamid Tank-Mixes Applied Preemergence

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Nader Soltani ◽  
Lynette R. Brown ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Weed Species ◽  
Navy Bean ◽  
Visible Injury ◽  
Common Lambsquarters ◽  
Weed Interference ◽  
Green Foxtail ◽  
White Bean ◽  
Bean Yield

Six field experiments were conducted during 2015 to 2017 in Ontario, Canada, to determine the efficacy of pethoxamid applied alone, and in combination with broadleaf herbicides, for the control of annual grass and broadleaved weeds in white navy bean. Visible injury was generally minimal (0 to 8%) with herbicide treatments evaluated. Weed control was variable depending on the weed species evaluated. Pethoxamid,S-metolachlor, halosulfuron, imazethapyr, sulfentrazone, pethoxamid + halosulfuron, pethoxamid + imazethapyr, and pethoxamid + sulfentrazone controlled redroot pigweed 82 to 98%; common ragweed 19 to 93%; common lambsquarters 49 to 84%; and green foxtail 47 to 92% in white bean. Weed biomass and weed density reductions were similar to visible control ratings for herbicides evaluated. Weed interference delayed white bean maturity and reduced yield by 50% in this study. Weed interference in plots sprayed with pethoxamid,S-metolachlor, and sulfentrazone reduced white bean yield 36%. White bean yield was similar to the weed-free with other herbicides evaluated. This study concludes that there is potential for the tank-mix of pethoxamid with halosulfuron, imazethapyr, or sulfentrazone for weed control in white bean production.

Biologically effective dose of glyphosate as influenced by weed size in corn

2016 ◽  
Vol 96 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Effective Dose ◽  
Weed Control ◽  
Field Trials ◽  
Biologically Effective Dose ◽  
Limited Information ◽  
Weed Species ◽  
Common Ragweed ◽  
Time Of Application ◽  
Green Foxtail ◽  
Lamb’S Quarters

There is limited information on the effect of weed size at the time of application on glyphosate efficacy in Ontario. Eleven field trials were conducted over a 3 yr period (2010–2012) in Ontario to determine the biologically effective dose of glyphosate applied postemergence (POST) in corn at doses of 112.5–1350 g acid equivalent (a.e.) ha−1 for the control of various grass and broadleaved weed species when the weeds were 10, 20 or 30 cm in height. The GR90 for redroot pigweed, common ragweed, common lamb’s-quarters, barnyardgrass, and green foxtail were 353, 630, 621, 763, and <112.5 g a.e. ha−1 when applied at 10 cm weed height, 235, 201, 906, 868, and 296 g a.e. ha−1 when applied at 20 cm weed height, and 792, >1350, >1350, 912, and 675 g a.e. ha−1 when applied at 30 cm weed height, respectively. Corn yields were maximized when glyphosate was applied to weeds that were up to 10 cm in height, but was reduced with later glyphosate application timings. The results of this study reinforce the importance of early POST weed control in corn.

Biologically Effective Dose and Selectivity of SAN 1269H (BAS 662H) for Weed Control in Corn (Zea mays)

1999 ◽  
Vol 13 (2) ◽  
pp. 283-289 ◽  
Author(s):  
Peter H. Sikkema ◽  
Stevan Z. Knezevic ◽  
Allan S. Hamill ◽  
François J. Tardif ◽  
Kevin Chandler ◽  
...  
Keyword(s):  
Effective Dose ◽  
Weed Control ◽  
Field Experiments ◽  
Leaf Growth ◽  
Amaranthus Retroflexus ◽  
Ambrosia Artemisiifolia ◽  
Biologically Effective Dose ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Wild Buckwheat

Field experiments were conducted in 1996 and 1997 at five locations in southwestern Ontario to develop dose-response curves for SAN 1269H (SAN 835H plus dicamba) for weed control and crop tolerance in corn. SAN 1269H controlled wild buckwheat (Polygonum convolvulusL.), common ragweed (Ambrosia artemisiifoliaL.), common lambsquarters (Chenopodium albumL.), pigweeds (Amaranthus retroflexusL. andA. powelliiS. Wats.), barnyardgrass [Echinochloa crus-galli(L.) Beauv.], and yellow foxtail [Setaria glauca(L.) Beauv.]. Biologically effective doses of SAN 1269H (BAS 662H) were 440, 430, 180, and 40 g/ha for yellow foxtail, barnyard grass, wild buckwheat, and common ragweed, respectively. The biologically effective dose (that which provides 90% reduction in weed dry matter) for common lambsquarters was 560 g/ha when SAN 1269H was applied preemergence (PRE) and 110 g/ha when applied postemergence (POST). When applied PRE at a rate of 420 g/ha, pigweed was controlled, whereas only 85 g/ha was required when applied POST. Grain yield increased with dose of SAN 1269H and did not differ with time of application. Temporary crop injury was observed when SAN 1269H was applied at the four- to six-leaf growth stage. Optimum corn yields were achieved with doses of 100 to 250 g/ha.

Biologically-Effective-Dose of Metribuzin, Applied Preemergence and Postemergence, for the Control of Waterhemp (Amaranthus tuberculatus) with Different Mechanisms of Resistance to Photosystem II-inhibiting herbicides

Weed Science ◽  
2021 ◽  
pp. 1-34
Author(s):  
David B. Westerveld ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Patrick J. Tranel ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Effective Dose ◽  
Field Experiments ◽  
Target Site ◽  
Biologically Effective Dose ◽  
Ps Ii ◽  
Calculated Dose ◽  
Amaranthus Tuberculatus ◽  
Target Site Resistance ◽  
Effective Doses

Abstract Photosystem II (PS II)-inhibitor herbicide resistance in Ontario waterhemp [Amaranthus tuberculatus (Moq.) Sauer] population is conferred via target-site resistance (TSR) and non-target-site resistance (NTSR) mechanisms. Metribuzin-resistant (MR) A. tuberculatus is due to TSR,. Conversely, in other populations of PS II-resistant A. tuberculatus, plants are resistant to atrazine but metribuzin-sensitive (MS). The objective of this study was to determine the biologically-effective-dose of metribuzin applied PRE and POST for the control of MS and MR A. tuberculatus. Ten field experiments were conducted in 2019 and 2020 to determine the effective doses of metribuzin for 50, 80, and 95% control of MS and MR A. tuberculatus. Metribuzin applied PRE at the calculated doses of 133, 350, and 1070 g ai ha-1 controlled MS A. tuberculatus 50, 80, and 95%, respectively, whereas the calculated doses of 7868 and 17533 g ai ha-1 controlled MR A. tuberculatus 50 and 80%, respectively at 12 WAA. Metribuzin applied POST at the calculated doses of 245 and 1480 g ai ha-1 controlled MS A. tuberculatus 50 and 80%, respectively; the calculated dose for 50% MR A. tuberculatus control was greater than the highest dose (17920 g ai ha-1) included in this study. Metribuzin at 560 and 1120 g ha-1 and pyroxasulfone/flumioxazin (240 g ai ha-1) applied PRE controlled MS A. tuberculatus 88, 95, and 98%, respectively at 12 WAA. The aforementioned treatments controlled MR A. tuberculatus 0, 4, and 93%, respectively at 12 WAA. Metribuzin at 560 and 1120 g ha-1 and fomesafen (240 g ai ha-1) applied POST controlled MS A. tuberculatus 65, 70, and 78%, and MR A. tuberculatus 0, 1, and 49%, respectively at 12 WAA. Based on these results, NTSR PS II-resistant A. tuberculatus (enhanced metabolism) is controlled with metribuzin applied PRE and POST, in contrast TSR PS II-resistant A. tuberculatus (glycine264serine altered target site) is not controlled with metribuzin.

Flat-cutting loosening in the system of fallow cultivation of chernozem soil and weediness of crops

2017 ◽  
Vol 1 (92) ◽  
pp. 78-84
Author(s):  
G. Koval ◽  
M. Kaliyevskiy ◽  
V. Yeshchenko ◽  
I. Martyniuk ◽  
N. Martyniuk
Keyword(s):  
Species Composition ◽  
Crop Rotation ◽  
Field Experiments ◽  
Early Spring ◽  
Weed Species ◽  
Wild Mustard ◽  
Spring Crop ◽  
White Campion ◽  
Investigation Methods ◽  
Top Soil

The article presents the results of field experiments, where on the basis of podsolized heavy loamy chernozem the influence of replacement of mouldboard ploughing with nonmouldboard cultivation over top soil weediness, weediness at the beginning and end of spring crop vegetation and weed species composition before harve sting were studied. Investigation methods of main fall ploughing under spring crops of five-course rotation: soybeans–rape–wheat–flax–barley at the depths of 15-17, 20-22, 25-27 cm were conducted after post-harvest field tillage. Analysis of data on contamination of the top soil with weed seeds have shown that with the replacement of fall main mouldboard ploughing gwith nonmouldboard cultivation the figure before sowing of all crops withdifferent tillage depthat crop rotation average increased by 131-132%. It caused the increase of actual weed infestation of all crops and at the beginning and end of spring crop vegetationafter different depths of fall nonmouldboard cultivation compared with ploughing at crop rotation average it was 120–132 and 123-138%respectively. Species composition of weeds afterthe replacement of main fall mouldboard ploughing with nonmouldboard cultivation remained mainlyunchanged; although in rape plantings the proportion of white campion and early spring weed sincreased, in wheat plantings– wild mustard andscentless mayweed, insoybean plantings– late spring weeds, in flax plantings– white campion, and in barley plantings– scarlet pimpernel.

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