Performance of Tank Mix Partners with Isoxaflutole Across the Cotton Belt

Abstract BASF Corporation has developed P-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor-resistant cotton and soybean that will allow growers to use isoxaflutole in future weed management programs. In 2019 and 2020, a multi-state research project was conducted non-crop to examine weed control following isoxaflutole applied preemergence alone and with a number of tank mix partners at high and low labeled rates. At 28 DAT, Palmer amaranth was controlled ≥95% at 6 of 7 locations with isoxaflutole plus the high rate of diuron or fluridone. These same combinations provided the greatest control 42 DAT at 4 of 7 locations. Where large crabgrass was present, isoxaflutole plus the high rate of diuron, fluridone, pendimethalin, or S-metolachlor or isoxaflutole plus the low rate of fluometuron controlled large crabgrass ≥95% in 2 of 3 locations 28 DAT. In 2 of 3 locations, isoxaflutole plus the high rate of pendimethalin or S-metolachlor improved large crabgrass control 42 DAT when compared to isoxaflutole alone. At 21 DAT, morningglory was controlled ≥95% at all locations with isoxaflutole plus the high rate of diuron and at 3 of 4 locations with isoxaflutole plus the high rate of fluometuron. At 42 DAT at all locations, isoxaflutole plus diuron or fluridone and isoxaflutole plus the high rate of fluometuron improved morningglory control compared to isoxaflutole alone. These results suggest that isoxaflutole applied preemergence alone or in tank mixture is efficacious on a number of cross-spectrum annual weeds in cotton and extended weed control may be achieved when isoxaflutole is tank mixed with a number of soil residual herbicides.

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Weed Management with Glyphosate- and Glufosinate-Based Systems in PHY 485 WRF Cotton

Weed Technology ◽

10.1614/wt-d-10-00008.1 ◽

2011 ◽

Vol 25 (2) ◽

pp. 183-191 ◽

Cited By ~ 31

Author(s):

Jared R. Whitaker ◽

Alan C. York ◽

David L. Jordan ◽

A. Stanley Culpepper

Keyword(s):

Weed Control ◽

Weed Management ◽

Fiber Quality ◽

Palmer Amaranth ◽

Weed Species ◽

Crop Tolerance ◽

The North ◽

Annual Grasses ◽

Resistance Trait ◽

Cotton Belt

Glyphosate-resistant (GR) Palmer amaranth has become a serious pest in parts of the Cotton Belt. Some GR cotton cultivars also contain the WideStrike™ insect resistance trait, which confers tolerance to glufosinate. Use of glufosinate-based management systems in such cultivars could be an option for managing GR Palmer amaranth. The objective of this study was to evaluate crop tolerance and weed control with glyphosate-based and glufosinate-based systems in PHY 485 WRF cotton. The North Carolina field experiment compared glyphosate and glufosinate alone and in mixtures applied twice before four- to six-leaf cotton. Additional treatments included glyphosate and glufosinate mixed withS-metolachlor or pyrithiobac applied to one- to two-leaf cotton followed by glyphosate or glufosinate alone on four- to six-leaf cotton. All treatments received a residual lay-by application. Excellent weed control was observed from all treatments on most weed species. Glyphosate was more effective than glufosinate on glyphosate-susceptible (GS) Palmer amaranth and annual grasses, while glufosinate was more effective on GR Palmer amaranth. Annual grass and GS Palmer amaranth control by glyphosate plus glufosinate was often less than control by glyphosate alone but similar to or greater than control by glufosinate alone, while mixtures were more effective than either herbicide alone on GR Palmer amaranth. Glufosinate caused minor and transient injury to the crop, but no differences in cotton yield or fiber quality were noted. This research demonstrates glufosinate can be applied early in the season to PHY 485 WRF cotton without concern for significant adverse effects on the crop. Although glufosinate is often less effective than glyphosate on GS Palmer amaranth, GR Palmer amaranth can be controlled with well-timed applications of glufosinate. Use of glufosinate in cultivars with the WideStrike trait could fill a significant void in current weed management programs for GR Palmer amaranth in cotton.

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Annual weed management in isoxaflutole-resistant soybean using a two-pass weed control strategy

Weed Technology ◽

10.1017/wet.2019.21 ◽

2019 ◽

Vol 33 (03) ◽

pp. 411-425

Author(s):

Andrea Smith ◽

Nader Soltani ◽

Allan J. Kaastra ◽

David C. Hooker ◽

Darren E. Robinson ◽

...

Keyword(s):

Weed Control ◽

Weed Management ◽

Field Experiments ◽

High Rate ◽

Grass Species ◽

Annual Grass ◽

Common Lambsquarters ◽

Control Programs ◽

The One ◽

Herbicide Programs

AbstractTransgenic crops are being developed with herbicide resistance traits to expand innovative weed management solutions for crop producers. Soybean with traits that confer resistance to the hydroxyphenylpyruvate dioxygenase herbicide isoxaflutole is under development and will provide a novel herbicide mode of action for weed management in soybean. Ten field experiments were conducted over 2 years (2017 and 2018) on five soil textures with isoxaflutole-resistant soybean to evaluate annual weed control using one- and two-pass herbicide programs. The one-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, at a low rate (52.5 + 210 g ai ha−1), medium rate (79 + 316 g ai ha−1), and high rate (105 + 420 g ai ha−1); and glyphosate applied early postemergence (EPOST) or late postemergence (LPOST). The two-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, followed by glyphosate applied LPOST, and glyphosate applied EPOST followed by LPOST. At 4 weeks after the LPOST application, control of common lambsquarters, pigweed species, common ragweed, and velvetleaf was variable at 25% to 69%, 49% to 86%, and 71% to 95% at the low, medium, and high rates of isoxaflutole plus metribuzin, respectively. Isoxaflutole plus metribuzin at the low, medium, and high rates controlled grass species evaluated (i.e., barnyardgrass, foxtail, crabgrass, and witchgrass) 85% to 97%, 75% to 99%, and 86% to 100%, respectively. All two-pass weed management programs provided 98% to 100% control of all species. Weed control improved as the rate of isoxaflutole plus metribuzin increased. Two-pass programs provided excellent, full-season annual grass and broadleaf weed control in isoxaflutole-resistant soybean.

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Effects of Seeding Date and Weed Control on Switchgrass Establishment

Weed Technology ◽

10.1614/wt-d-11-00078.1 ◽

2012 ◽

Vol 26 (2) ◽

pp. 248-255 ◽

Cited By ~ 11

Author(s):

William S. Curran ◽

Matthew R. Ryan ◽

Matthew W. Myers ◽

Paul R. Adler

Keyword(s):

Weed Control ◽

Broad Spectrum ◽

Weed Management ◽

Late Summer ◽

Seeding Rate ◽

Study Region ◽

Seeding Date ◽

Central Pennsylvania ◽

Annual Weeds ◽

Broad Spectrum Treatment

We tested the effects of seeding date and weed control during switchgrass establishment in a field experiment that was conducted in central Pennsylvania in 2007 and repeated in 2008. Switchgrass was no-till seeded in early May, late May, and mid-June, and three postemergence weed management treatments were evaluated, including Mow (only a single mowing), Broadleaf (2,4-D + dicamba), and Broad Spectrum (2,4-D + dicamba + atrazine + quinclorac). Switchgrass density increased at later seeding dates, except in 2008, when the middle seeding date had the lowest density. In both years, weed biomass in late summer was lowest in the last seeding date of the Broad Spectrum treatment. In contrast, switchgrass biomass in late summer was greatest in the first seeding date of the Broad Spectrum treatment in both years. In the year after establishment (production year), plots were split to test the effects of supplemental weed control, composed of metsulfuron + 2,4-D applied in May, on total aboveground yield. Supplemental control in the production year increased total aboveground yield in the Mow treatment only, indicating that effective weed control during the establishment year might reduce the need for weed control in the following year. Although maximum aboveground yield was achieved when switchgrass was seeded in May and herbicides were used, results from our experiment suggest that seeding switchgrass at a relatively high seeding rate in June in our study region and mowing annual weeds to reduce competition and prevent seed production could be an effective strategy if minimizing herbicide use is a priority.

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Weed Management in Imidazolinone-Resistant Corn with Imazapic

Weed Technology ◽

10.1614/wt-03-204r ◽

2004 ◽

Vol 18 (4) ◽

pp. 1018-1022 ◽

Cited By ~ 6

Author(s):

Joyce Tredaway Ducar ◽

John W. Wilcut ◽

John S. Richburg

Keyword(s):

Weed Control ◽

Weed Management ◽

Rate Control ◽

Field Studies ◽

Redroot Pigweed ◽

Herbicide Treatments ◽

Rate Controlled ◽

Prickly Sida ◽

Better Than ◽

Large Crabgrass

Field studies were conducted in 1992 and 1993 to evaluate imazapic alone and in postemergence (POST) mixtures with atrazine or bentazon for weed control in imidazolinone-resistant corn treated with carbofuran. Nicosulfuron and nicosulfuron plus atrazine also were evaluated. Imazapic at 36 and 72 g ai/ha controlled large crabgrass 85 and 92%, respectively, which was equivalent to control obtained with nicosulfuron plus atrazine. Imazapic at the higher rate controlled large crabgrass better than nicosulfuron alone. Imazapic at 36 and 72 g/ha controlled Texas panicum 88 and 99%, respectively, and at the higher rate control was equivalent to that obtained with nicosulfuron alone or in mixture with atrazine. Imazapic plus bentazon POST controlled Texas panicum less than imazapic at the lower rate applied alone. Redroot pigweed was controlled 100% with all herbicide treatments. Imazapic at either rate alone or in tank mixture with bentazon or atrazine controlled prickly sida >99%, which was superior to control obtained with nicosulfuron or nicosulfuron plus atrazine. Smallflower, entireleaf, ivyleaf, pitted, and tall morningglories were controlled 96% or greater with all herbicide treatments except nicosulfuron alone. Sicklepod control was >88% with all imazapic treatments, whereas control from nicosulfuron alone was 72%. Corn yields were improved by the addition of POST herbicides with no differences among POST herbicide treatments.

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Weed Management in Peanut with Herbicide Combinations Containing Imazapic and Other Pesticides

Weed Technology ◽

10.1614/wt-08-041.1 ◽

2009 ◽

Vol 23 (1) ◽

pp. 6-10 ◽

Cited By ~ 8

Author(s):

David L. Jordan ◽

Sarah H. Lancaster ◽

James E. Lanier ◽

Bridget R. Lassiter ◽

P. Dewayne Johnson

Keyword(s):

North Carolina ◽

Weed Control ◽

Weed Management ◽

Common Ragweed ◽

Common Lambsquarters ◽

Yellow Nutsedge ◽

Pod Yield ◽

Final Experiment ◽

Pitted Morningglory ◽

Large Crabgrass

Research was conducted in North Carolina to compare weed control by various rates of imazapic POST alone or following diclosulam PRE. In a second experiment, weed control by imazapic applied POST alone or with acifluoren, diclosulam, or 2,4-DB was compared. In a final experiment, yellow nutsedge control by imazapic alone and with the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole was compared. Large crabgrass was controlled more effectively by imazapic POST than diclosulam PRE. Common lambsquarters, common ragweed, and eclipta were controlled more effectively by diclosulam PRE than imazapic POST. Nodding spurge was controlled similarly by both herbicides. Few differences in control were noted when comparing imazapic rates after diclosulam PRE. Applying either diclosulam PRE or imazapic POST alone or in combination increased peanut yield over nontreated peanut in five of six experiments. Few differences in pod yield were noted when comparing imazapic rates. Acifluorfen, diclosulam, and 2,4-DB did not affect entireleaf morningglory, large crabgrass, nodding spurge, pitted morningglory, and yellow nutsedge control by imazapic. Eclipta control by coapplication of imazapic and diclosulam exceeded control by imazapic alone. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole did not affect yellow nutsedge control by imazapic.

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Influence of Spray-Solution Temperature and Holding Duration on Weed Control with Premixed Glyphosate and Dicamba Formulation

Weed Technology ◽

10.1614/wt-d-15-00101.1 ◽

2016 ◽

Vol 30 (1) ◽

pp. 116-122 ◽

Cited By ~ 7

Author(s):

Pratap Devkota ◽

Fred Whitford ◽

William G. Johnson

Keyword(s):

Weed Control ◽

Palmer Amaranth ◽

High Rate ◽

Solution Temperature ◽

Weed Species ◽

Related Factors ◽

Spray Solution ◽

Giant Ragweed ◽

Pitted Morningglory ◽

Low Rate

Water is the primary carrier for herbicide application, and carrier-water–related factors can influence herbicide performance. In a greenhouse study, premixed formulation of glyphosate plus dicamba was mixed in deionized (DI) water at 5, 18, 31, 44, or 57 C and applied immediately. In a companion study, glyphosate and dicamba formulation was mixed in DI water at temperatures of 5, 22, 39, or 56 C and sprayed after the herbicide solution was left at the respective temperatures for 0, 6, or 24 h. In both studies, glyphosate plus dicamba was applied at 0.275 plus 0.137 kg ae ha−1(low rate), and 0.55 plus 0.275 kg ha−1(high rate), respectively, to giant ragweed, horseweed, Palmer amaranth, and pitted morningglory. Glyphosate plus dicamba applied at a low rate with solution temperature of 31 C provided 14% and 26% greater control of giant ragweed and pitted morningglory, respectively, compared to application at solution temperature of 5 C. At both rates of glyphosate and dicamba formulation, giant ragweed and pitted morningglory control was 15% or greater at solution temperature of 44 C compared to 5 C. Weed control was not affected with premixture of glyphosate and dicamba applied ≤ 24 h after mixing herbicide. When considering solution temperature, glyphosate and dicamba applied at low rate provided 13 and 6% greater control of Palmer amaranth and pitted morningglory, respectively, with solution temperature of 22 C compared to 5 C. Similarly, giant ragweed control was 8% greater with solution temperature of 39 C compared to 5 C. Glyphosate and dicamba applied at high rate provided 8% greater control of giant ragweed at solution temperature of 22 or 39 C compared to 5 C. Therefore, activity of premixed glyphosate and dicamba could be reduced with spray solution at lower temperature; however, the result is dependent on weed species.

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Preemergence Weed Control in Southeastern Forest Nurseries

Weed Science ◽

10.1017/s004317450002720x ◽

1973 ◽

Vol 21 (4) ◽

pp. 363-366 ◽

Cited By ~ 1

Author(s):

T. R. Dill ◽

M. C. Carter

Keyword(s):

United States ◽

Pinus Taeda ◽

Weed Control ◽

Loblolly Pine ◽

Southeastern United States ◽

Pinus Elliottii ◽

Slash Pine ◽

High Rate ◽

Forest Nurseries ◽

Low Rate

Weed control trials were conducted on loblolly pine (Pinus taedaL.) or slash pine (Pinus elliottiiEngelm.) seedbeds at 12 locations in the southeastern United States. Good weed control was obtained from 2,4-bis-(isopropylamino)-6-(methylthio)-s-triazine (prometryne) at 2.2 and 4.5 kg/ha;N,N-dimethyl-2,2-diphenylacetamide (diphenamid) at 4.5 and 9 kg/ha; α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) at 1.1 and 2.2 kg/ha; and 2-ethylthio-4,6-bis-isopropylamino-s-triazine (GS-16068) at 2.2 and 4.5 kg/ha as preemergence applications immediately followed by irrigation. Diphenamid and trifluralin treatments were not injurious to either pine species at either rate. GS-16068 was only slightly injurious at the high rate at one location. Prometryne was injurious at two locations at the high rate and at one location at the low rate.

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Response of Annual Weed Species to Glufosinate and Glyphosate

Weed Technology ◽

10.1017/s0890037x00046170 ◽

1999 ◽

Vol 13 (3) ◽

pp. 542-547 ◽

Cited By ~ 28

Author(s):

Brent E. Tharp ◽

Oliver Schabenberger ◽

James J. Kells

Keyword(s):

Weed Management ◽

Chenopodium Album ◽

Ambrosia Artemisiifolia ◽

Weed Species ◽

Common Ragweed ◽

Common Lambsquarters ◽

Setaria Faberi ◽

Giant Foxtail ◽

Annual Weeds ◽

Large Crabgrass

The recent introduction of glufosinate-resistant and glyphosate-resistant crops provides growers with new options for weed management. Information is needed to compare the effectiveness of glufosinate and glyphosate on annual weeds. Greenhouse trials were conducted to determine the response of barnyardgrass (Echinochloa crus-galli), common lambsquarters (Chenopodium album), common ragweed (Ambrosia artemisiifolia), fall panicum (Panicum dichotomiflorum), giant foxtail (Setaria faberi), large crabgrass (Digitaria sanguinalis), and velvetleaf (Abutilon theophrasti) to glufosinate and glyphosate. The response of velvetleaf and common lambsquarters was investigated at multiple stages of growth. Glufosinate and glyphosate were applied to each weed species at logarithmically incremented rates. The glufosinate and glyphosate rates that provided a 50% reduction in aboveground weed biomass, commonly referred to as GR50values, were compared using nonlinear regression techniques. Barnyardgrass, common ragweed, fall panicum, giant foxtail, and large crabgrass responded similarly to glufosinate and glyphosate. Common lambsquarters 4 to 8 cm in height was more sensitive to glufosinate than glyphosate. In contrast, 15- to 20-cm tall-velvetleaf was more sensitive to glyphosate than glufosinate.

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Utility of glufosinate in postemergence row middle weed control in Florida plasticulture production

Weed Technology ◽

10.1017/wet.2019.6 ◽

2019 ◽

Vol 33 (03) ◽

pp. 495-502

Author(s):

Shaun M. Sharpe ◽

Nathan S. Boyd

Keyword(s):

Weed Control ◽

Weed Management ◽

High Dose ◽

Vegetable Production ◽

Suitable Alternative ◽

Additional Control ◽

Comparable Control ◽

Low Rate

AbstractHerbicides are the foundation for row-middle weed control in Florida plasticulture production. Paraquat is commonly used as a burndown herbicide, and resistance issues have subsequently developed. Halosulfuron is mixed with PRE and POST herbicides to provide additional control of nutsedge. The objective of the study was to determine glufosinate efficacy on weeds emerging in the row-middle and suitability in mixture with halosulfuron for nutsedge control. For total weed control, the high dose of glufosinate (983 g ai ha–1) gave the highest overall control (98% and 64% at 4 wk after treatment for experiments 1 and 2, respectively), and the low rate of glufosinate (656 g ha–1) (67% and 39%) gave results comparable to paraquat (57% and 44%). The high glufosinate dose and paraquat gave comparable control of Brazil pusley (74% to 77% control). Glufosinate + halosulfuron mixture had lower efficacy on Brazil pusley than halosulfuron + paraquat mixture. Glufosinate application reduced grass densities, whereas paraquat did not. Increasing the glufosinate dose did not further decrease grass densities. Similar trends in grass control were also demonstrated in their respective mixtures. Mixing halosulfuron with glufosinate or paraquat did not provide consistent reductions in nutsedge densities, nor did adding paraquat or glufosinate further reduce densities compared with halosulfuron alone for the 4-wk study period. Both paraquat and glufosinate antagonized halosulfuron and reduced efficacy on nutsedge. Compared to controls, there was a reduction between expected and actual nutsedge control for paraquat and glufosinate (25% and 36%), respectively. For total weed control, glufosinate is a suitable alternative to paraquat for row-middle weed management in vegetable production.

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Comparison of 2,4-D, dicamba and halauxifen-methyl alone or in combination with glyphosate for preplant weed control

Weed Technology ◽

10.1017/wet.2020.83 ◽

2020 ◽

pp. 1-6

Author(s):

M. Carter Askew ◽

Charles W. Cahoon ◽

Alan C. York ◽

Michael L. Flessner ◽

David B. Langston ◽

...

Keyword(s):

Field Study ◽

Weed Control ◽

High Rate ◽

Evening Primrose ◽

Auxin Herbicides ◽

Low Rate

Abstract A field study was conducted in 2017 and 2018 to determine foliar efficacy of halauxifen-methyl, 2,4-D, or dicamba applied alone and in combination with glyphosate at preplant burndown timing. Experiments were conducted near Painter, VA; Rocky Mount, NC; Jackson, NC; and Gates, NC. Control of horseweed, henbit, purple deadnettle, cutleaf evening primrose, curly dock, purple cudweed, and common chickweed were evaluated. Halauxifen-methyl applied at 5 g ae ha−1 controlled small and large horseweed 89% and 79%, respectively, and was similar to control by dicamba applied at 280 g ae ha−1. Both rates of 2,4-D—533 g ae ha−1(low rate [LR]) or 1,066 g ae ha−1 (high rate [HR])—were less effective than halauxifen-methyl and dicamba for controlling horseweed. Halauxifen-methyl was the only auxin herbicide to control henbit (90%) and purple deadnettle (99%). Cutleaf evening primrose was controlled 74% to 85%, 51%, and 4% by 2,4-D, dicamba, and halauxifen-methyl, respectively. Dicamba and 2,4-D controlled curly dock 59% to 70% and were more effective than halauxifen-methyl (5%). Auxin herbicides applied alone controlled purple cudweed and common chickweed 21% or less. With the exception of cutleaf evening primrose (35%) and curly dock (37%), glyphosate alone provided 95% or greater control of all weeds evaluated. These experiments demonstrate halauxifen-methyl effectively (≥79%) controls horseweed, henbit, and purple deadnettle, whereas common chickweed, curly dock, cutleaf evening primrose, and purple cudweed control by the herbicide is inadequate (≤7%).

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