Weed Response to Co-Application of Herbicides and Acephate in Cotton

Determining compatibility of pesticides is important in developing effective management practices and adjusting to outbreaks of pests in cotton (Gossypium hirsutism L.). Field experiments were conducted in 2013 and 2014 to determine the effect of chloroacetamide herbicides with residual activity only and acephate with foliar activity against thrips (Frankliniella spp.) on control of emerged weeds by glyphosate, glufosinate, and a mixture of these herbicides. The residual herbicides acetochlor and S-metolachlor as well as the insecticide acephate did not affect control of emerged common ragweed (Ambrosia artemisiifolia L.) and Palmer amaranth (Amaranthus palmeri Watts.). Results from these trials indicate that weed control will not be compromised with co-application of glufosinate, glyphosate, and glufosinate plus glyphosate with acetochlor or S-metolachlor applied alone or with acephate.

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Rimsulfuron Tank Mixed with Flumioxazin, Pendimethalin, or Oryzalin for Control of Broadleaf Weeds in Citrus

HortTechnology ◽

10.21273/horttech.22.5.638 ◽

2012 ◽

Vol 22 (5) ◽

pp. 638-643 ◽

Cited By ~ 4

Author(s):

Amit J. Jhala ◽

Analiza H.M. Ramirez ◽

Megh Singh

Keyword(s):

Weed Control ◽

Field Experiments ◽

Residual Activity ◽

Ambrosia Artemisiifolia ◽

Herbicide Application ◽

Control Efficacy ◽

Central Florida ◽

Control Option ◽

Citrus Groves ◽

Florida Citrus

Herbicides are usually applied multiple times by growers for season long weed control in Florida citrus (Citrus sp.). Rimsulfuron, a sulfonylurea herbicide has been recently registered for control of certain grasses and broadleaf weeds in citrus. To increase the weed control spectrum and reduce application cost, citrus growers often prefer to tank mix herbicides. Field experiments were conducted in 2010 and 2011 in citrus groves in central Florida to evaluate weed control efficacy and crop safety of rimsulfuron applied alone or in tank mixes with flumioxazin, pendimethalin, or oryzalin. Herbicides were applied sequentially in spring and fall in both years on the same experimental plot. Results suggested that rimsulfuron applied alone controlled >80% broadleaf and grass weeds up to 30 days after treatment (DAT) and was comparable to tank mixing rimsulfuron with pendimethalin or oryzalin; however, control was reduced beyond 30 DAT. Rimsulfuron tank mixed with flumioxazin was the most effective treatment at 30 and 60 DAT that provided, respectively, ≥88% and >75%, control of broadleaf weeds including brazil pusley (Richardia brasiliensis), dog fennel (Eupatorium capillifolium), common ragweed (Ambrosia artemisiifolia), cotton weed (Froelichia floridana), and virginia pepperweed (Virginia virginicum) compared with other treatments. Control of natalgrass (Melinis repens) was higher in all tank mix treatments compared with rimsulfuron applied alone with no difference among tank mix partners. Rimsulfuron tank mixed with pendimethalin or oryzalin had no advantage over rimsulfuron applied alone for control of broadleaf weeds. Among sequential applications, weed control was better after fall herbicide application (August) compared with spring (April) because of residual activity of fall applied herbicides. Rimsulfuron tank mixed with flumioxazin will provide citrus growers with an additional weed control option.

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

Weed Technology ◽

10.1017/s0890037x00041749 ◽

1999 ◽

Vol 13 (2) ◽

pp. 283-289 ◽

Cited By ~ 13

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.

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Effect of Cover Crop Biomass, Strip-Tillage Residue Disturbance Width, and PRE-Herbicide Placement on Cotton Weed Control, Yield, and Economics

Weed Technology ◽

10.1017/wet.2021.8 ◽

2021 ◽

pp. 1-31

Author(s):

Andrew J. Price ◽

Robert L. Nichols ◽

Trent A. Morton ◽

Kipling S. Balkcom ◽

Timothy L. Grey ◽

...

Keyword(s):

Weed Control ◽

Cover Crop ◽

Management Practices ◽

Field Experiments ◽

Conservation Tillage ◽

Acetolactate Synthase ◽

Palmer Amaranth ◽

Weed Species ◽

Strip Tillage ◽

Large Crabgrass

Conservation tillage adoption continues to be threatened by glyphosate and acetolactate synthase-resistant Palmer amaranth and other troublesome weeds. Field experiments were conducted from autumn 2010 through crop harvest in 2013 at two locations in Alabama to evaluate the effect of integrated management practices on weed control and seed cotton yield in glyphosate-resistant cotton. The effects of a cereal rye cover crop using high or low biomass residue, followed by wide or narrow within-row strip-tillage, and three PRE herbicide regimes were evaluated. The three PRE regimes were: 1) pendimethalin at 0.84 kg ae ha-1 plus fomesafen at 0.28 kg ai ha-1 applied broadcast, 2) pendimethalin plus fomesafen applied banded on the row, or 3) no PRE. Each PRE treatment was followed by (fb) glyphosate (1.12 kg ae ha-1) applied POST fb a LAYBY applications of diuron (1.12 kg ai ha-1) plus MSMA (2.24 kg ai ha-1). Low residue plots ranged in biomass from 85 to 464 kg ha-1, while high biomass plots ranged from 3119 to 6929 kg ha-1. In most comparisons, surface disturbance width, residue amount, and soil applied herbicide placement did not influence within-row weed control; however, broadcast PRE resulted in increased carpetweed, large crabgrass, Palmer amaranth, tall morningglory, and yellow nutsedge weed control in row middles compared to plots receiving banded PRE. In addition, high residue increased carpetweed, common purslane, large crabgrass, Palmer amaranth, sicklepod, and tall morningglory weed control between rows. Use of banded PRE herbicides resulted in equivalent yield and revenue in four of six comparisons compared to those with broadcast PRE herbicide application; however, this would likely result in many between row weed escapes. Thus, conservation tillage cotton would benefit from broadcast soil-applied herbicide applications regardless of residue amount and tillage width when infested with Palmer amaranth and other troublesome weed species.

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Safety and efficacy of linuron with or without an adjuvant or S-metolachlor for POST control of Palmer amaranth (Amaranthus palmeri) in sweetpotato

Weed Technology ◽

10.1017/wet.2021.27 ◽

2021 ◽

pp. 1-18

Author(s):

Levi D. Moore ◽

Katherine M. Jennings ◽

David W. Monks ◽

Ramon G. Leon ◽

David L. Jordan ◽

...

Keyword(s):

Nonionic Surfactant ◽

Weed Control ◽

Critical Period ◽

Total Yield ◽

Field Studies ◽

Palmer Amaranth ◽

Amaranthus Palmeri ◽

Foliar Injury ◽

Protoporphyrinogen Oxidase ◽

Safety And Efficacy

Abstract Field studies were conducted to evaluate linuron for POST control of Palmer amaranth in sweetpotato to minimize reliance on protoporphyrinogen oxidase (PPO)-inhibiting herbicides. Treatments were arranged in a two by four factorial where the first factor consisted of two rates of linuron (420 and 700 g ai ha−1), and the second factor consisted of linuron applied alone or in combinations of linuron plus a nonionic surfactant (NIS) (0.5% v/v), linuron plus S-metolachlor (800 g ai ha−1), or linuron plus NIS plus S-metolachlor. In addition, S-metolachlor alone and nontreated weedy and weed-free checks were included for comparison. Treatments were applied to ‘Covington’ sweetpotato 8 d after transplanting (DAP). S-metolachlor alone provided poor Palmer amaranth control because emergence had occurred at applications. All treatments that included linuron resulted in at least 98 and 91% Palmer amaranth control 1 and 2 wk after treatment (WAT), respectively. Including NIS with linuron did not increase Palmer amaranth control compared to linuron alone, but increased sweetpotato injury and subsequently decreased total sweetpotato yield by 25%. Including S-metolachlor with linuron resulted in the greatest Palmer amaranth control 4 WAT, but increased crop foliar injury to 36% 1 WAT compared to 17% foliar injury from linuron alone. Marketable and total sweetpotato yield was similar between linuron alone and linuron plus S-metolachlor or S-metolachlor plus NIS treatments, though all treatments resulted in at least 39% less total yield than the weed-free check resulting from herbicide injury and/or Palmer amaranth competition. Because of the excellent POST Palmer amaranth control from linuron 1 WAT, a system including linuron applied 7 DAP followed by S-metolachlor applied 14 DAP could help to extend residual Palmer amaranth control further into the critical period of weed control while minimizing sweetpotato injury.

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KIH-485 and S-metolachlor Efficacy Comparisons in Conventional and No-Tillage Corn

Weed Technology ◽

10.1614/wt-05-048r2.1 ◽

2006 ◽

Vol 20 (3) ◽

pp. 622-626 ◽

Cited By ~ 38

Author(s):

Patrick W. Geier ◽

Phillip W. Stahlman ◽

John C. Frihauf

Keyword(s):

Weed Control ◽

Field Experiments ◽

Conventional Tillage ◽

Palmer Amaranth ◽

Effective Control ◽

No Tillage ◽

Green Foxtail

Field experiments were conducted during 2003 and 2004 to compare the effectiveness of KIH-485 and S-metolachlor for PRE weed control in no-tillage and conventional-tillage corn. Longspine sandbur control increased as KIH-485 or S-metolachlor rates increased in conventional-tillage corn, but control did not exceed 75% when averaged over experiments. Both herbicides controlled at least 87% of green foxtail with the exception of no-tillage corn in 2004, when KIH-485 was more effective than S-metolachlor at lower rates. Palmer amaranth control ranged from 85 to 100% in 2003 and 80 to 100% in 2004, with the exception of only 57 to 76% control at the lowest two S-metolachlor rates in 2004. Puncturevine control exceeded 94% with all treatments in 2003. In 2004, KIH-485 controlled 86 to 96% of the puncturevine, whereas S-metolachlor controlled only 70 to 81%. Mixtures of atrazine with KIH-485 or S-metolachlor generally provided the most effective control of broadleaf weeds studied.

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Influence of Selected Fungicides on Efficacy of Clethodim and 2,4-DB

Peanut Science ◽

10.3146/ps11-14.1 ◽

2012 ◽

Vol 39 (2) ◽

pp. 121-126 ◽

Cited By ~ 1

Author(s):

Gurinderbir S. Chahal ◽

David L. Jordan ◽

Barbara B. Shew ◽

Rick L. Brandenburg ◽

James D. Burton ◽

...

Keyword(s):

North Carolina ◽

Sampling Interval ◽

Palmer Amaranth ◽

Amaranthus Palmeri ◽

Solution Ph ◽

Affect Control ◽

Solution Preparation ◽

Positive Correlations ◽

Sampling Times ◽

Large Crabgrass

Abstract A range of fungicides and herbicides can be applied to control pests and optimize peanut yield. Experiments were conducted in North Carolina to define biological and physicochemical interactions when clethodim and 2,4-DB were applied alone or with selected fungicides. Pyraclostrobin consistently reduced large crabgrass [Digitaria sanguinalis (L.) Scop.] control by clethodim. Chlorothalonil and tebuconazole plus trifloxystrobin reduced large crabgrass control by clethodim in two of four experiments while prothioconazole plus tebuconazole and flutriafol did not affect control. Palmer amaranth [Amaranthus palmeri S. Wats] control by 2,4-DB was not affected by these fungicides. Although differences in spray solution pH were noted among mixtures of clethodim plus crop oil concentrate or 2,4-DB and fungicides, the range of pH was 4.40 to 4.92 and 6.72 to 7.20, respectively, across sampling times of 0, 6, 24, and 72 h after solution preparation. Permanent precipitates were formed when clethodim, crop oil concentrate, and chlorothalonil were co-applied at each sampling interval. Permanent precipitates were not observed when clethodim and crop oil concentrate were included with other fungicides or when 2,4-DB was mixed with fungicides. Significant positive correlations were noted for Palmer amaranth control by 2,4-DB and solution pH but not for clethodim and solution pH.

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Weed Control with Halauxifen-Methyl Applied Alone and in Mixtures with 2,4-D, Dicamba, and Glyphosate

Weed Technology ◽

10.1017/wet.2018.48 ◽

2018 ◽

Vol 32 (5) ◽

pp. 597-602 ◽

Cited By ~ 7

Author(s):

Marcelo Zimmer ◽

Bryan G. Young ◽

William G. Johnson

Keyword(s):

Weed Control ◽

Field Experiments ◽

Common Ragweed ◽

Synthetic Auxin ◽

Redroot Pigweed ◽

Giant Ragweed ◽

Auxin Herbicides ◽

Control Spectrum

AbstractSynthetic auxin herbicides such as 2,4-D and dicamba are often utilized to control broadleaf weeds in preplant burndown applications to soybean. Halauxifen-methyl is a new synthetic auxin herbicide for broadleaf weed control in preplant burndown applications to corn, cotton, and soybean at low use rates (5 g ae ha–1). Field experiments were conducted to evaluate efficacy and weed control spectrum of halauxifen-methyl applied alone and in mixtures with 2,4-D (560 g ae ha–1), dicamba (280 g ae ha–1), and glyphosate (560 g ae ha–1). Glyphosate-resistant (GR) horseweed was controlled with halauxifen-methyl applied alone (90% control) and in mixtures (87% to 97% control) 35 d after treatment (DAT). Common ragweed was controlled 93% with halauxifen-methyl applied alone and 91% to 97% in mixtures 35 DAT. Halauxifen-methyl applied alone resulted in poor giant ragweed control 21 DAT (73% control); however, mixtures of halauxifen-methyl with 2,4-D, dicamba, or glyphosate controlled giant ragweed (86% to 98% control). Halauxifen-methyl alone resulted in poor redroot pigweed control (62% control) 21 DAT; however, mixtures of halauxifen-methyl with dicamba, 2,4-D, or glyphosate controlled redroot pigweed (89% to 98% control). Halauxifen-methyl controls GR horseweed and common ragweed applied alone and in mixtures with other synthetic auxin herbicides and glyphosate. Furthermore, mixing 2,4-D or dicamba with halauxifen-methyl can increase the weed control spectrum in preplant burndown applications.

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Weed Management in Southeastern Peanut (Arachis hypogaea) with AC 263,222

Weed Technology ◽

10.1017/s0890037x00045851 ◽

1996 ◽

Vol 10 (1) ◽

pp. 145-152 ◽

Cited By ~ 20

Author(s):

John S. Richburg ◽

John W. Wilcut ◽

Daniel L. Colvin ◽

Gerald R. Wiley

Keyword(s):

Weed Control ◽

Arachis Hypogaea ◽

Weed Management ◽

Field Experiments ◽

Common Ragweed ◽

Yellow Nutsedge ◽

Application Rates ◽

Ac 263,222

Field experiments conducted at four locations in Georgia and two locations in Florida during 1992 and 1993 evaluated AC 263,222 application rates and timings, systems, and mixtures for weed control, peanut injury, and yield. All rates of AC 263,222 applied early POST (EPOST) or POST controlledIpomoeamorningglories and smallflower morningglory at least 90%, and purple and yellow nutsedge at least 81%. Florida beggarweed and sicklepod control generally was highest when metolachlor was applied PPI followed by AC 263,222 applied EPOST at 71 g/ha, AC 263,222 at 27 or 36 g/ha plus bentazon plus paraquat applied POST, or with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Acifluorfen and acifluorfen plus bentazon reduced Florida beggarweed and sicklepod control at several locations when applied in mixture with AC 263,222. Common ragweed and hairy indigo control were 85 to 95% with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Highest peanut yields were obtained with treatments providing high levels of weed control.

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Residual Activity of ACCase-Inhibiting Herbicides on Monocot Crops and Weeds

Weed Technology ◽

10.1017/wet.2018.13 ◽

2018 ◽

Vol 32 (4) ◽

pp. 364-370 ◽

Cited By ~ 1

Author(s):

Zachary D. Lancaster ◽

Jason K. Norsworthy ◽

Robert C. Scott

Keyword(s):

Weed Control ◽

Field Experiments ◽

Residual Activity ◽

Sprinkler Irrigation ◽

Grain Sorghum ◽

Rainfall Event ◽

Rice Grain ◽

Acetyl Coa Carboxylase ◽

Herbicide Treatments ◽

Residual Control

AbstractField experiments were conducted in 2014 and 2015 in Fayetteville, Arkansas, to evaluate the residual activity of acetyl-CoA carboxylase (ACCase)–inhibiting herbicides for monocot crop injury and weed control. Conventional rice, quizalofop-resistant rice, grain sorghum, and corn crops were evaluated for tolerance to soil applications of six herbicides (quizalofop at 80 and 160 g ai ha–1, clethodim at 68 and 136 g ai ha–1, fenoxaprop at 122 g ai ha–1, cyhalofop at 313 g ai ha–1, fluazifop at 210 and 420 g ai ha–1, and sethoxydim at 140 and 280 g ai ha–1). Overhead sprinkler irrigation of 1.3 cm was applied immediately after treatment to half of the plots, and the crops planted into the treated plots at 0, 7, and 14 d after herbicide treatment. In 2014, injury from herbicide treatments increased with activation for all crops evaluated, except for quizalofop-resistant rice. At 14 d after treatment (DAT) in 2014, corn and grain sorghum were injured 19% and 20%, respectively, from the higher rate of sethoxydim with irrigation activation averaged over plant-back dates. Conventional rice was injured 13% by the higher rate of fluazifop in 2014. Quizalofop-resistant rice was injured no more than 4% by any of the graminicides evaluated in either year. In 2015, a rainfall event occurred within 24 h of initiating the experiment; thus, there were no differences between activation via irrigation or by rainfall. However, as in 2014, grain sorghum and corn were injured 16% and 13%, respectively, by the higher rate of sethoxydim, averaged over plant-back dates. All herbicides provided little residual control of grass weeds, mainly broadleaf signalgrass and barnyardgrass. These findings indicate the need to continue allowing a plant-back interval to rice following a graminicide application, unless quizalofop-resistant rice is to be planted. The plant-back interval will vary by graminicide and the amount of moisture received following the application.

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Palmer Amaranth (Amaranthus palmeri) Control by Glufosinate plus Fluometuron Applied Postemergence to WideStrike®Cotton

Weed Technology ◽

10.1614/wt-d-12-00158.1 ◽

2013 ◽

Vol 27 (2) ◽

pp. 291-297 ◽

Cited By ~ 14

Author(s):

Kelly A. Barnett ◽

A. Stanley Culpepper ◽

Alan C. York ◽

Lawrence E. Steckel

Keyword(s):

United States ◽

Weed Control ◽

Acetolactate Synthase ◽

The United States ◽

Palmer Amaranth ◽

Effective Control ◽

Yield Response ◽

Amaranthus Palmeri ◽

Cotton Yield ◽

Cotton Cultivar

Glyphosate-resistant (GR) weeds, especially GR Palmer amaranth, are very problematic for cotton growers in the Southeast and Midsouth regions of the United States. Glufosinate can control GR Palmer amaranth, and growers are transitioning to glufosinate-based systems. Palmer amaranth must be small for consistently effective control by glufosinate. Because this weed grows rapidly, growers are not always timely with applications. With widespread resistance to acetolactate synthase-inhibiting herbicides, growers have few herbicide options to mix with glufosinate to improve control of larger weeds. In a field study using a WideStrike®cotton cultivar, we evaluated fluometuron at 140 to 1,120 g ai ha−1mixed with the ammonium salt of glufosinate at 485 g ae ha−1for control of GR Palmer amaranth 13 and 26 cm tall. Standard PRE- and POST-directed herbicides were included in the systems. Glufosinate alone injured the WideStrike® cotton less than 10%. Fluometuron increased injury up to 25% but did not adversely affect yield. Glufosinate controlled 13-cm Palmer amaranth at least 90%, and there was no improvement in weed control nor a cotton yield response to fluometuron mixed with glufosinate. Palmer amaranth 26 cm tall was controlled only 59% by glufosinate. Fluometuron mixed with glufosinate increased control of the larger weeds up to 28% and there was a trend for greater yields. However, delaying applications until weeds were 26 cm reduced yield 22% relative to timely application. Our results suggest fluometuron mixed with glufosinate may be of some benefit when attempting to control large Palmer amaranth. However, mixing fluometuron with glufosinate is not a substitute for a timely glufosinate application.

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