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.

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.

scholarly journals Weed management in cranberry bean with linuron

2011 ◽  
Vol 91 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Nader Soltani ◽  
Robert Nurse ◽  
Christy Shropshire ◽  
Peter Sikkema
Keyword(s):  
Weed Management ◽  
Management Strategy ◽  
Dry Weight ◽  
Field Studies ◽  
Research Station ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Wild Mustard ◽  
Green Foxtail

Soltani, N., Nurse, R. E., Shropshire, C. and Sikkema, P. H. 2011. Weed management in cranberry bean with linuron. Can. J. Plant Sci. 91: 881–888. Field studies were conducted at the Huron Research Station near Exeter, Ontario, in 2006 to 2009 to determine if the sequential application of trifluralin plus imazethapyr applied preplant incorporated (PPI) followed by linuron applied pre-emergence (PRE) at various doses can be used as an effective weed management strategy in cranberry bean production. There was minimal crop injury (6% or less) with various herbicides evaluated at 1 and 4 wk after emergence (WAE). Trifluralin plus imazethapyr applied PPI provided 97 to 100% control of common lambsquarters, 100% control of redroot pigweed, 99 to 100% control of wild mustard, 93 to 100% control of common ragweed, and 97 to 100% control of green foxtail. Linuron applied PRE provided 11 to 100% control of common lambsquarters, 90 to 100% control of redroot pigweed, 78 to 100% control of wild mustard, 71 to 100% control of common ragweed, and 20 to 100% control of green foxtail. The sequential application of trifluralin plus imazethapyr applied PPI followed by linuron applied PRE at various doses provided 100% control of common lambsquarters, 100% control of redroot pigweed, 100% control of wild mustard, 96 to 100% control of common ragweed, and 97 to 100% control of green foxtail. Weed density and shoot dry weight correlated well with the level of weed control. All of the herbicide treatments evaluated increased cranberry bean yield compared with the weedy control. Based on these results the sequential application of imazethapyr plus trifluralin applied PPI followed by linuron applied PRE at 1000 and 2500 g a.i. ha−1 provides a safe and efficacious weed management strategy in cranberry bean production.

Comparison of weed communities in Manitoba ecoregions and crops

2000 ◽  
Vol 80 (4) ◽  
pp. 963-972 ◽  
Author(s):  
R. C. Van Acker ◽  
A. G. Thomas ◽  
J. Y. Leeson ◽  
S. Z. Knezevic ◽  
B. L. Frick
Keyword(s):  
Weed Management ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Canada Thistle ◽  
Wild Mustard ◽  
Polygonum Convolvulus ◽  
Weed Communities ◽  
Green Foxtail ◽  
Poaceae Family ◽  
Weed Survey

In 1997, a weed survey was conducted during July and August in fields of wheat, barley, oat, canola and flax in Manitoba. Field selection was based on a stratified-random sampling methodology using ecodistricts as strata. Species in the Poaceae family were most commonly observed in the survey, followed by species in the Polygonaceae, Asteraceae and Brassicaceae families. The six most abundant weed species were green foxtail [Setaria viridis (L.) Beauv.], wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), Canada thistle (Cirsium arvense L.), redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.). The survey highlighted significant differences between ecoregions and between crops in residual weed infestations. The weed community in the Boreal Transition ecoregion was dominated by seven species, whereas fields in the Aspen Parkland and Lake Manitoba Plain ecoregions were dominated by two species and the Interlake Plain ecoregion was dominated by only one species. Although significant differences were found between the weed communities in crops, they were not as great as differences between ecoregions. The Manitoba residual weed community in 1997 was very similar to that reported for 1978–1981 and 1986, suggesting that the same species should remain a focus for weed management. Key words: Weed survey, weed relative abundance, weed distributions, Manitoba ecoregions

Weed control in soybean using pyroxasulfone and sulfentrazone

2015 ◽  
Vol 95 (6) ◽  
pp. 1199-1204 ◽  
Author(s):  
Kimberly D. Belfry ◽  
Kristen E. McNaughton ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Chenopodium Album ◽  
Ambrosia Artemisiifolia ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Industry Standard ◽  
Control Option ◽  
Green Foxtail ◽  
Glycine Max L

Belfry, K. D., McNaughton, K. E. and Sikkema, P. H. 2015. Weed control in soybean using pyroxasulfone and sulfentrazone. Can. J. Plant Sci. 95: 1199–1204. Pyroxasulfone and sulfentrazone are new herbicides currently being evaluated for weed control in soybean [Glycine max (L.) Merr.] in Ontario, Canada. Seven experiments were conducted over a 3-yr period (2011 to 2013) at Ridgetown and Exeter, Ontario, to evaluate weed management using pyroxasulfone, sulfentrazone and their tank-mixes relative to the industry standard, imazethapyr plus metribuzin. Tank-mixing pyroxasulfone and sulfentrazone provided up to 97, 46, 60, 100 and 71% control of common lambsquarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), green foxtail [Setaria viridis (L.) Beauv.], Powell amaranth [Amaranthus powellii (S.) Wats.] and velvetleaf (Abutilon theophrasti Medic.), respectively, at 2 wk after treatment. Control with pyroxasulfone and sulfentrazone was improved when tank-mixed, relative to application of each herbicide separately. Although control was variable across weed species, no difference in control was identified between pyroxasulfone plus sulfentrazone and imazethapyr plus metribuzin. Soybean yield was up to 2.7, 2.4 and 2.9 t ha−1 for pyroxasulfone, sulfentrazone and pyroxasulfone plus sulfentrazone application, yet imazethapyr plus metribuzin provided the highest yield (3.3 t ha−1). This research demonstrates that pyroxasulfone plus sulfentrazone may be used as a valuable weed control option in soybean; however, weed community composition may limit herbicidal utility.

Influence of application timing and herbicide rate on the efficacy of tolpyralate plus atrazine

2019 ◽  
Vol 33 (03) ◽  
pp. 448-458 ◽  
Author(s):  
Brendan A. Metzger ◽  
Nader Soltani ◽  
Alan J. Raeder ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Weed Management ◽  
Field Experiments ◽  
Integrated Weed Management ◽  
Herbicide Application ◽  
Weed Species ◽  
Common Ragweed ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Green Foxtail ◽  
Equivalent Control

AbstractEffective POST herbicides and herbicide mixtures are key components of integrated weed management in corn; however, herbicides vary in their efficacy based on application timing. Six field experiments were conducted over 2 yr (2017–2018) in southwestern Ontario, Canada, to determine the effects of herbicide application timing and rate on the efficacy of tolpyralate, a new 4-hydroxyphenyl pyruvate dioxygenase inhibitor. Tolpyralate at 15, 30, or 40 g ai ha−1 in combination with atrazine at 500 or 1,000 g ai ha−1 was applied PRE, early POST, mid-POST, or late POST. Tolpyralate + atrazine at rates ≥30 + 1,000 g ha−1 provided equivalent control of common lambsquarters and Powell amaranth applied PRE or POST, whereas no rate applied PRE controlled common ragweed, velvetleaf, barnyardgrass, or green foxtail. Common ragweed, common lambsquarters, velvetleaf, and Powell amaranth were controlled equally regardless of POST timing. In contrast, control of barnyardgrass and green foxtail declined when herbicide application was delayed to the late-POST timing, irrespective of herbicide rate. Similarly, corn grain yield declined within each tolpyralate + atrazine rate when herbicide applications were delayed to late-POST timing. Overall, the results of this study indicate that several monocot and dicot weed species can be controlled with tolpyralate + atrazine with an early to mid-POST herbicide application timing, before weeds reach 30 cm in height, and Powell amaranth and common lambsquarters can also be controlled PRE. Additionally, this study provides further evidence highlighting the importance of effective, early-season weed control in corn.

Herbicide Combinations for Postemergent Weed Control in Safflower (Carthamus tinctorius)

1990 ◽  
Vol 4 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Douglas A. Derksen ◽  
H.-Henning Muendel
Keyword(s):  
Weed Control ◽  
Field Studies ◽  
Carthamus Tinctorius ◽  
Quality Data ◽  
Wild Oat ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Yield And Quality ◽  
Green Foxtail ◽  
Field Control

Greenhouse and field studies were conducted to examine the interaction of sethoxydim or fluazifop-P tank mixed with chlorsulfuron or thiameturon for selective weed control in safflower. Under greenhouse conditions, the addition of chlorsulfuron to sethoxydim or fluazifop-P slightly improved the control of green foxtail above that achieved with either herbicide alone. Control of wild oat and wild mustard was similar with the tank mixes and each herbicide alone. In the field, control of wild oat with sethoxydim or fluazifop-P was not altered by adding chlorsulfuron or thiameturon in tank mixes. Similarly, control of common lambsquarters and wild mustard with chlorsulfuron or thiameturon was not affected by adding either sethoxydim or fluazifop-P in tank mixes. Plant height, date of flowering, seed yield, and quality data indicated that safflower tolerated these herbicides applied alone or in combination. Sethoxydim or fluazifop-P tank mixed with chlorsulfuron or thiameturon provide a postemergent alternative for selective control of grass and broadleaf weeds in safflower.

Evaluating Seed Shatter of Economically Important Weed Species

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Nikki R. Burton ◽  
Hugh J. Beckie ◽  
Christian J. Willenborg ◽  
Steven J. Shirtliffe ◽  
Jeff J. Schoenau ◽  
...  
Keyword(s):  
Weed Management ◽  
Field Experiments ◽  
Management Strategies ◽  
Wild Oat ◽  
Population Abundance ◽  
Weed Seed ◽  
Weed Species ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Crop Maturity

The increasing occurrence of herbicide resistance, along with no new herbicide modes of action developed in over 30 yr, have increased the need for nonherbicidal weed management strategies and tactics. Harvest weed seed control (HWSC) practices have been successfully adopted in Australia to manage problematic weeds. For HWSC to be effective, a high proportion of weed seeds must be retained on the plant at crop maturity. This 2-yr (2014, 2015) study evaluated seed shatter of wild oat, green foxtail, wild mustard, and cleavers in both an early (field pea) and late (spring wheat) maturity crop in field experiments at Scott, Saskatchewan. Seed shatter was assessed using shatter trays collected once a week during crop ripening stage, as well as at two crop maturation or harvest stages (swathing, direct-combining). Seed shatter differed among weed species, but was similar between crops at maturity: ca. 30% for wild oat, 5% for cleavers, < 2% for wild mustard, and < 1% for green foxtail. Overall, seed shatter of wild oat occurred sooner and at greater levels during the growing season compared with the other weed species. Viability of both shattered and plant-retained seeds was relatively high for all species. The small amount of seed shatter of cleavers, wild mustard, and green foxtail suggests that these species may be suitable candidates for HWSC. Due to the amount and timing of wild oat seed shatter, HWSC may not reduce population abundance of this grassy weed.

Chemical Control of Annual Weeds in Field Beans (Vicia faba) in Central Spain

Weed Science ◽  
1992 ◽  
Vol 40 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Rafael C. Garcia De Arevalo ◽  
Carmen A. Lusarreta ◽  
Carmen B. Neyra ◽  
Mercedes A. Sanchez ◽  
Pedro J. H. Algarra
Keyword(s):  
Chemical Control ◽  
Mean Field ◽  
Field Studies ◽  
Dry Beans ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Herbicide Treatments ◽  
Annual Weeds ◽  
Field Beans

Field studies were conducted over 3 yr to investigate the effect of chemicals on field beans density and weed control. Predominant weed species were common lambsquarters, fumitory, henbit, corn poppy, prostrate knotweed, and wild mustard. All herbicide treatments except linuron injured field beans. Mean field beans survival at harvest was 78% in alachlor and 84% in alachlor containing treatments. Only 5% survived atrazine at 1.9 kg ai ha−1. Ethalfluralin, pendimethalin, simazine, terbutylazine plus terbutryn, and trifluralin treatments produced plant survival values of 56, 82, 86, 74, and 71%, respectively. Chemical control of the main weed species overshadowed the detrimental effect on field beans density, and thus most herbicide treatments except alachlor resulted in increased dry beans yield. The best overall results occurred with linuron, simazine, terbuthylazine plus terbutryn, and pendimethalin which increased dry beans yields 76, 63, 56, and 40%, respectively, over the control plots. Common lambsquarters was the dominant weed, and prostrate knotweed and corn poppy were the most difficult and the easiest species to control, respectively.

Significance of Atrazine as a Tank-Mix Partner with Tembotrione

2011 ◽  
Vol 25 (3) ◽  
pp. 299-302 ◽  
Author(s):  
Martin M. Williams ◽  
Rick A. Boydston ◽  
R. Ed Peachey ◽  
Darren Robinson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sweet Corn ◽  
Field Studies ◽  
Species Group ◽  
Corn Yield ◽  
Weed Species ◽  
Corn Production ◽  
Common Lambsquarters ◽  
Regulatory Changes

Manufacturers of several POST corn herbicides recommend tank-mixing their herbicides with atrazine to improve performance; however, future regulatory changes may place greater restrictions on atrazine use and limit its availability to growers. Our research objectives were to quantify the effects of tank-mixing atrazine with tembotrione compared to tembotrione alone on (1) weed control, (2) variability in weed control, and (3) sweet corn yield components and yield variability. Field studies were conducted for 2 yr each in Illinois, Oregon, Washington, and Ontario, Canada. Tembotrione at 31 g ha−1 was applied alone and with atrazine at 370 g ha−1 POST at the four- to five-collar stage of corn. The predominant weed species observed in the experiment were common to corn production, including large crabgrass, wild-proso millet, common lambsquarters, and velvetleaf. For nearly every weed species and species group, the addition of atrazine improved tembotrione performance by increasing mean levels of weed control 3 to 45% at 2 wk after treatment. Adding atrazine reduced variation (i.e., standard deviation) in control of the weed community by 45%. Sweet corn ear number and ear mass were 9 and 13% higher, respectively, and less variable when atrazine was applied with tembotrione, compared to tembotrione alone. Additional restrictions or the complete loss of atrazine for use in corn will necessitate major changes in sweet corn weed management systems.

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