Response of Teff, Barnyardgrass, and Broadleaf Weeds to Postemergence Herbicides

2014 ◽  
Vol 28 (2) ◽  
pp. 371-376
Author(s):  
O. Steven Norberg ◽  
Joel Felix
Keyword(s):  
Weed Control ◽  
Warm Season ◽  
Field Studies ◽  
The United States ◽  
Production Costs ◽  
Grain Production ◽  
Annual Grass ◽  
Food Grain ◽  
Postemergence Herbicides ◽  
Grass Weed

Teff is a warm-season C4 annual grass crop grown for forage and food grain that has recently increased in production in parts of the United States. Hay from teff is well suited for livestock, especially horses. The objective of this study was to evaluate teff and weed response to selected herbicides in field studies conducted at the Malheur Experiment Station, Ontario, OR in 2009 and 2010. Herbicides were applied POST when teff was at the four-leaf stage. Broadleaf weed control at 21 d after treatment was greater than 91% across herbicide treatments. Only the premix of 2.5 g ai ha−1florasulam + 99 g ae ha−1fluroxypyr + 15 g ai ha−1pyroxsulam provided acceptable control of barnyardgrass. Due primarily to barnyardgrass competition, teff treated with a premix of 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam produced 7,200 kg ha−1of teff hay compared with 4,800 kg ha−1of teff hay for 2,4-D and dicamba and 4,200 kg ha−1teff hay when no herbicides were used. Teff grain production was greater with 2.5 g ha−1florasulam + 99 g ha−1fluroxypyr + 15 g ha−1pyroxsulam compared with any of the other treatments. The use of a premix of florasulam + fluroxypyr + pyroxsulam would improve broadleaf and grass weed control in ‘Tiffany' and ‘Dessie' teff varieties, improve hay and grain yield, and reduce production costs.

Reduced Rates of Postemergence Herbicides for Weed Control in Sweet Corn (Zea mays)

1993 ◽  
Vol 7 (4) ◽  
pp. 995-1000 ◽  
Author(s):  
John O'Sullivan ◽  
William J. Bouw
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Sweet Corn ◽  
Field Studies ◽  
Annual Grass ◽  
Experiment Station ◽  
Postemergence Herbicides

The efficacy of reduced rates of POST herbicides for weed control in sweet corn was evaluated over a three-year period in field studies conducted at the Horticultural Experiment Station, Simcoe, Ontario. POST applications of metolachlor/cyanazine, cyanazine/atrazine and metolachlor/atrazine at 1/2X and 1/4X of labelled rates controlled broadleaf weeds comparable to that of standard labelled rates. Control exceeded 94% each year. Annual grass control was reduced with below-label rates, especially for cyanazine/atrazine and metolachlor/atrazine. A 1/2X application of nicosulfuron/rimsulfuron, following the 1/4X rate of cyanazine/atrazine, significantly improved grass control, compared to cyanazine/atrazine applied alone. Below-label rates did not result in decreased sweet corn yields.

Grass Weed Control for Soybean (Glycine max) on Clay Soil

1991 ◽  
Vol 5 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Larry G. Heatherly ◽  
C. Dennis Elmore
Keyword(s):  
Control System ◽  
Glycine Max ◽  
Weed Control ◽  
Clay Soil ◽  
Field Studies ◽  
Optimum Yield ◽  
Weed Infestation ◽  
Repeated Applications ◽  
Postemergence Herbicides ◽  
Grass Weed

Field studies were conducted for four consecutive years to determine if repeated applications of trifluralin (preplant incorporated), metolachlor (preemergence), and fluazifop (postemergence) herbicides alone or combined could be utilized in soybean to effectively control grass weed populations and maintain optimum yield in an irrigated environment where metribuzin plus dinoseb (preemergence) and 2,4-DB plus linuron (postemergence) were used as a standard weed control system. After repeated applications each year, all treatments maintained similar yields that were no different from yields obtained from the standard system. Grass weed infestation did not increase significantly in the treatment that received only the standard weed control herbicides over the duration of the study.

Weed Control in Soybeans (Glycine max) with Reduced Rates of Postemergence Herbicides

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Michael S. Defelice ◽  
William B. Brown ◽  
Richard J. Aldrich ◽  
Barry D. Sims ◽  
Dan T. Judy ◽  
...  
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Seed Production ◽  
Field Studies ◽  
Weed Seed ◽  
Giant Foxtail ◽  
Full Rate ◽  
Postemergence Herbicides ◽  
Grass Weed

Field studies were conducted at three sites in Missouri in 1986 and 1987 to evaluate the performance of below-label rates of bentazon, acifluorfen, and chlorimuron tank mixed with sethoxydim and applied to soybeans 7 and 14 days after planting to evaluate broadleaf and grass weed control and weed seed production. Sequential applications of 0.25X-labeled rates of all three broadleaf herbicides tank mixed with 0.5X sethoxydim rates controlled giant foxtail, velvetleaf, and common cocklebur equivalent to one application of standard-labeled rates of the same tank mixes. Single applications of below-labeled rates of the postemergence herbicides did not control weeds, and soybean yields were not equal to sequential 0.25X or single full-rate treatments. A preemergence treatment of clomazone plus imazaquin applied at labeled rates controlled weeds, and soybean yields were equal to a handweeded check in both years at all test locations. Weeds survived and produced seed to reinfest the plots the following year unless nearly 100% control was achieved.

scholarly journals Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 2: grass species

Weed Science ◽  
2020 ◽  
pp. 1-19
Author(s):  
Lauren M. Schwartz-Lazaro ◽  
Lovreet S. Shergill ◽  
Jeffery A. Evans ◽  
Muthukumar V. Bagavathiannan ◽  
Shawn C. Beam ◽  
...  
Keyword(s):  
The United States ◽  
Grass Species ◽  
Annual Grass ◽  
Weed Seed ◽  
Weed Species ◽  
Seed Shattering ◽  
Physiological Maturity ◽  
Rate Of Progression ◽  
Multiple Regions ◽  
Grass Weed

Abstract Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.

Fluazifop-P Tank-Mixtures with Clethodim for Annual Grass Control in Flax (Linum usitatissimum)

1994 ◽  
Vol 8 (4) ◽  
pp. 673-678 ◽  
Author(s):  
David A. Wall
Keyword(s):  
Weed Control ◽  
Active Ingredient ◽  
Linum Usitatissimum ◽  
Field Studies ◽  
Wild Oat ◽  
Annual Grass ◽  
Foliar Injury ◽  
Leaf Stage ◽  
Green Foxtail

Field studies were undertaken in 1992 and 1993 to investigate the control of wild oat and green foxtail in flax with reduced rates of fluazifop-P and clethodim applied as tank-mixtures. Fluazifop-P plus clethodim at 50 + 18 g ai/ha controlled wild oat and green foxtail and was as effective as full rates of either herbicide applied alone. These rates represent a 20% reduction in total amount of active ingredient required to control wild oat and green foxtail. Application of fluazifop-P, and/or clethodim prior to the 3- to 4-leaf stage failed to control late emerging grass weeds. Application of graminicide mixtures at or after the 3- to 4-leaf stage controlled late emerging grass weeds and did not affect flax yield. When applied late, fluazifop-P at 175 g/ha tended to reduce flax yield, although weed control was acceptable and no foliar injury was observed following treatment. The efficacy of graminicide mixtures was reduced by addition of bromoxynil plus MCPA to the spray mix.

scholarly journals Reduced Herbicide Antagonism of Grass Weed Control through Spray Application Technique

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1131 ◽  
Author(s):  
Luke H. Merritt ◽  
Jason Connor Ferguson ◽  
Ashli E. Brown-Johnson ◽  
Daniel B. Reynolds ◽  
Te-Ming Tseng ◽  
...  
Keyword(s):  
Weed Control ◽  
Environmental Sustainability ◽  
Field Studies ◽  
Italian Ryegrass ◽  
Spray Application ◽  
The Third ◽  
Application Method ◽  
Application Methods ◽  
Over The Top ◽  
Grass Weed

Dicamba and 2,4-D tolerance traits were introduced to soybean and cotton, allowing for over the top applications of these herbicides. Avoiding antagonism of glyphosate and clethodim by dicamba or 2,4-D is necessary to achieve optimum weed control. Three field studies were conducted in fallow fields with broadleaf signalgrass (Urochloa platyphylla) and Italian ryegrass (Lolium perenne ssp. multiflorum) pressure. A tractor-mounted dual boom sprayer was modified to spray one of three application methods: (1) two herbicides tanked-mixed (TMX); (2) two herbicides in separate tanks mixed in the boom line (MIL); and (3) two herbicides in separate tanks applied through separate booms simultaneously (SPB). One study compared the three application methods with sethoxydim applied with bentazon, the second compared clethodim applied with dicamba or 2,4-D, and the third compared glyphosate applied with dicamba or 2,4-D. In most cases over all three trials, there was a 7–15% increase in efficacy when using the SPB application method. Antagonism of all the herbicide combinations above was observed when applied using the TMX and MIL methods. In some cases, antagonism was avoided when using the SPB method. The separate boom application method increased efficacy, which allowed herbicides to be used more effectively, resulting in improved economic and environmental sustainability of herbicide applications.

Evaluation of sequential applications of quizalofop-P-ethyl and florpyrauxifen-benzyl in acetyl CoA carboxylase-resistant rice

2020 ◽  
pp. 1-5
Author(s):  
Tameka L. Sanders ◽  
Jason A. Bond ◽  
Benjamin H. Lawrence ◽  
Bobby R. Golden ◽  
Thomas W. Allen ◽  
...  
Keyword(s):  
Weed Control ◽  
Rice Yield ◽  
Field Studies ◽  
Growth Stages ◽  
Acetyl Coa Carboxylase ◽  
Weed Species ◽  
Rough Rice ◽  
Sequential Treatments ◽  
Acetyl Coenzyme A Carboxylase ◽  
Grass Weed

Abstract Information on performance of sequential treatments of quizalofop-P-ethyl with florpyrauxifen-benzyl on rice is lacking. Field studies were conducted in 2017 and 2018 in Stoneville, MS, to evaluate sequential timings of quizalofop-P-ethyl with florpyrauxifen-benzyl included in preflood treatments of rice. Quizalofop-P-ethyl treatments were no quizalofop-P-ethyl; sequential applications of quizalofop-P-ethyl at 120 g ha−1 followed by (fb) 120 g ai ha−1 applied to rice in the 2- to 3-leaf (EPOST) fb the 4-leaf to 1-tiller (LPOST) growth stages or LPOST fb 10 d after flooding (PTFLD); quizalofop-P-ethyl at 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST or LPOST fb PTFLD; quizalofop-P-ethyl at 139 g ha−1 fb 100 g ha−1 EPOST fb LPOST and LPOST fb PTFLD; and quizalofop-P-ethyl at 85 g ha−1 fb 77 g ha−1 fb 77 g ha−1 EPOST fb LPOST fb PTFLD. Quizalofop-P-ethyl was applied alone and in mixture with florpyrauxifen-benzyl at 29 g ai ha−1 LPOST. Visible rice injury 14 d after PTFLD (DA-PTFLD) was no more than 3%. Visible control of volunteer rice (‘CL151’ and ‘Rex’) 7 DA-PTFLD was similar and at least 95% for each quizalofop-P-ethyl treatment. Barnyardgrass control with quizalofop-P-ethyl at 120 fb 120 g ha−1 LPOST fb PTFLD was greater (88%) in mixture with florpyrauxifen-benzyl. The addition of florpyrauxifen-benzyl to quizalofop-P-ethyl increased rough rice yield when quizalofop-P-ethyl was applied at 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST. Sequential applications of quizalofop-P-ethyl at 120 g ha−1 fb 120 g ha−1 EPOST fb LPOST, 100 g ha−1 fb 139 g ha−1 EPOST fb LPOST, or 139 g ha−1 fb 100 g ha−1 EPOST fb LPOST controlled grass weed species. The addition of florpyrauxifen-benzyl was not beneficial for grass weed control. However, because quizalofop-P-ethyl does not control broadleaf weeds, florpyrauxifen-benzyl could provide broad-spectrum weed control in acetyl coenzyme A carboxylase–resistant rice.

Herbicide-Resistant Canola (Brassica napus) Response and Weed Control with Postemergence Herbicides

2006 ◽  
Vol 20 (3) ◽  
pp. 551-557 ◽  
Author(s):  
Timothy L. Grey ◽  
Paul L. Raymer ◽  
David C. Bridges
Keyword(s):  
Weed Control ◽  
Field Studies ◽  
Italian Ryegrass ◽  
Wild Radish ◽  
Application Timing ◽  
Herbicide Resistant ◽  
Naturally Occurring ◽  
And Control ◽  
Postemergence Herbicides ◽  
Significant Injury

Field studies were conducted to evaluate weed control in herbicide-resistant canola in Georgia. The resistant canola cultivars and respective herbicides were ‘Pioneer 45A76’ and imazamox, ‘Hyola 357RR’ and glyphosate, and ‘2573 Invigor’ and glufosinate. Weed seed of Italian ryegrass and wild radish were sown simultaneously in October with canola and control of these species was evaluated along with other naturally occurring weeds. Herbicide treatments for the respective herbicide-resistant canola cultivar were imazamox at 0.035 and 0.071 kg ai/ha, glyphosate at 0.84 and 1.64 kg ae/ha, and glufosinate at 0.5 and 1.0 kg ai/ha. Herbicides were applied at one– two-leaf (LF) and three–four-LF canola stages. There was no significant injury to any canola cultivar as a result of herbicide rate or timing of application. By midseason (February), imazamox effectively controlled wild radish, henbit, and shepherd's-purse at both rates and at both timings. When applied to three–four-LF canola, the higher rates of glyphosate and glufosinate were required to provide 75% or greater control of Italian ryegrass, wild garlic, and henbit. Glufosinate did not adequately control wild radish at either rate or application timing. Greenhouse experiments provided similar results.

Antagonism of Graminicide Activity on Annual Grass Species by Imazethapyr

1992 ◽  
Vol 6 (2) ◽  
pp. 333-338 ◽  
Author(s):  
Paul F. Myers ◽  
Harold D. Coble
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Grass Species ◽  
Annual Grass ◽  
Antagonistic Interaction ◽  
Interaction Control ◽  
Grass Weed ◽  
Large Crabgrass

The interaction of imazethapyr and selected graminicides on annual grass control was studied in field experiments. Tank-mix combinations of imazethapyr with clethodim, fluazifop-P, quizalofop, or sethoxydim resulted in an antagonistic interaction. Control of large crabgrass, fall panicum, and broadleaf signalgrass by each graminicide decreased when tank-mixed with imazethapyr as compared with each graminicide applied alone. Sequential applications of imazethapyr, relative to each graminicide, successfully overcame the antagonism. Imazethapyr applied 5 d before or 1 d after each of the graminicides did not decrease grass weed control compared with each graminicide alone. Imazethapyr applied 3 or 1 d before, or the same day as the graminicides, generally decreased grass weed control.

scholarly journals Castor (Ricinus communisL.) Tolerance to Postemergence Herbicides and Weed Control Efficacy

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
W. James Grichar ◽  
Peter A. Dotray ◽  
Calvin L. Trostle
Keyword(s):  
Weed Control ◽  
Cucumis Melo ◽  
Field Studies ◽  
Control Efficacy ◽  
Untreated Check ◽  
Postemergence Herbicides

Potential US castor production is limited due to only one labeled herbicide (trifluralin). Field studies were conducted at two Texas locations during 2008 and 2009 to evaluate postemergence herbicides for castor tolerance and weed control efficacy. Clethodim and fluazifop-P-butyl caused no castor stunting while acifluorfen, bentazon, imazethapyr, and lactofen caused stunting which ranged from 5 to 46%. Imazapic and 2,4-DB caused the greatest stunting (44 to 99%) and resulted in castor yields of 0 to 45% of the untreated check. Acifluorfen, imazapic, imazethapyr, lactofen, and 2,4-DB controlled at least 80% smellmelon (Cucumis meloL. var. Dudaim Naud.) while clethodim and fluazifop-P-butyl controlled at least 98% Texas millet [Urochloa texana(Buckl.) R.Webster]. Imazapic and imazethapyr provided 57 to 75% Texas millet control. Results suggest that castor tolerance to the graminicides, clethodim, and fluazifop-P-butyl is high; however, castor injury and yield reductions with the postemergence applications of broadleaf herbicides suggest that these herbicides should not be used in castor production.

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