A Comparison of Weed Control in Herbicide-Resistant, Herbicide-Tolerant, and Conventional Corn

2008 ◽  
Vol 22 (4) ◽  
pp. 571-579 ◽  
Author(s):  
Ian C. Burke ◽  
Walter E. Thomas ◽  
Jayla R. Allen ◽  
Jim Collins ◽  
John W. Wilcut
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
System Control ◽  
Corn Yield ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Pitted Morningglory ◽  
Pre Treatment ◽  
Over The Top ◽  
Large Crabgrass

Experiments were conducted at three North Carolina research stations in 2003 to evaluate weed control and corn yield in glyphosate-resistant, glufosinate-resistant, imidazolinone-tolerant, and conventional corn weed management systems. Late-season control of common lambsquarters, large crabgrass, and yellow nutsedge increased with metolachlor PRE compared with no PRE herbicide treatment. Common lambsquarters, pitted morningglory, entireleaf morningglory, spurred anoda, and tropic croton control was improved by a single early POST (EPOST) application regardless of herbicide system. Control of common lambsquarters, pitted morningglory, entireleaf morningglory, and spurred anoda was similar for glyphosate and glufosinate systems for each POST over-the-top (POT) herbicide system. A single EPOST application of imazethapyr plus imazapyr to imidazolinone-tolerant corn controlled common lambsquarters, pitted morningglory, entireleaf morningglory, and spurred anoda and was better than a single EPOST application of glyphosate, glufosinate, or nicosulfuron. Tropic croton was controlled ≥ 95% with glufosinate or glyphosate, applied once or twice, or in mixture with metolachlor. A single EPOST application of imazethapyr plus imazapyr or nicosulfuron did not control tropic croton. Common lambsquarters, entireleaf morningglory, large crabgrass, Palmer amaranth, and yellow nutsedge control was greater with a late-POST–directed (LAYBY) of ametryn than no LAYBY. Systems that did not include a POT herbicide system had the lowest percentage in the weed-free yield and the lowest yield. Treatments that included a POT system with or without a PRE treatment of metolachlor yielded within 5% of the weed-free treatment, regardless of herbicide system.

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

2009 ◽  
Vol 23 (1) ◽  
pp. 6-10 ◽  
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.

Interaction of Cultivar, Planting Pattern, and Weed Management Tactics in Peanut

Weed Science ◽  
2010 ◽  
Vol 58 (4) ◽  
pp. 442-448 ◽  
Author(s):  
G. T. Place ◽  
S. C. Reberg-Horton ◽  
D. L. Jordan
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Weed Species ◽  
Planting Pattern ◽  
Economic Return ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Pitted Morningglory ◽  
Herbicide Programs ◽  
Management Tactics

Planting peanut in narrow rows for weed control has not been investigated in recently released Virginia market peanut cultivars. Research was conducted in North Carolina from 2007 to 2009 to determine the effect of cultivar, planting pattern, and level of weed management inputs on weed control, peanut yield, and estimated economic return. Experiments consisted of three levels of weed management (clethodim applied POST, cultivation and hand-removal of weeds, and clethodim and appropriate broadleaf herbicides applied POST), three levels of planting pattern (single rows spaced 91 cm apart, standard twin rows spaced 20 cm apart on 91-cm centers, and narrow twin rows consisting of twin rows spaced 20 cm apart on 46-cm centers), and two Virginia cultivars (‘NC 12C’ and ‘VA 98R’). Weed management affected common lambsquarters, common ragweed, eclipta, nodding spurge, pitted morningglory, Texas millet, and yellow nutsedge control, irrespective of cultivar or planting pattern. Cultivar and planting pattern had only minor effects on weed control and interactions of these treatment factors seldom occurred. Weed control achieved with cultivation plus hand-removal was similar to weed management observed with grass and broadleaf herbicide programs. Pod yield did not differ among treatments when broadleaf weeds were the dominant species but did differ when Texas millet was the most prevalent weed. The highest yield with conventional herbicide weed management was in standard twin and narrow twin row planting patterns, although no differences among planting patterns were noted when cultivation and hand-removal were the primary weed management tactics. Differences in estimated economic return were associated with weed species, and interactions of treatment factors varied by year for that parameter.

Weed Management in Glyphosate-Resistant Corn with Glyphosate and Halosulfuron

2004 ◽  
Vol 18 (4) ◽  
pp. 1049-1057 ◽  
Author(s):  
Walter E. Thomas ◽  
Ian C. Burke ◽  
John W. Wilcut
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Weed Management ◽  
Field Studies ◽  
Crop Tolerance ◽  
Yellow Nutsedge ◽  
Net Returns ◽  
Glyphosate Formulation ◽  
Pre Treatment ◽  
Large Crabgrass

Three field studies were conducted at Lewiston Woodville, NC, in 2001 and 2002 to evaluate crop tolerance, weed control, grain yield, and net returns in glyphosate-resistant corn with various herbicide systems. Crop injury, weed control, and grain yield were not influenced by glyphosate formulation. Atrazine preemergence (PRE) and atrazine plus metolachlor PRE, averaged over postemergence (POST) systems, controlled Texas panicum at least 80 and 87%, respectively. Sequential glyphosate applications (early postemergence [EPOST] followed by [fb] POST) provided at least 99% control of Texas panicum compared with at least 86 and 88% control with glyphosate EPOST and glyphosate plus halosulfuron EPOST, respectively. Atrazine plus metolachlor PRE fb any glyphosate system controlled large crabgrass and goosegrass 89 to 100% and 94 to 100%, respectively. Sequential glyphosate treatments controlled large crabgrass and goosegrass at least 99 and 95%, respectively. Regardless of PRE system, glyphosate plus halosulfuron EPOST and sequential applications of glyphosate controlled common ragweed and common lambsquarters at least 99%, whereas glyphosate EPOST alone provided at least 88 and 96% control, respectively. Glyphosate plus halosulfuron EPOST and glyphosate sequentially controlled yellow nutsedge similarly and more consistently than glyphosate EPOST. Regardless of PRE treatment, sequential glyphosate applications provided at least 98% control of entireleaf and pitted morningglory, whereas glyphosate EPOST controlled at least 64 and 62%, respectively. Glyphosate EPOST and the sequential glyphosate EPOST fb POST systems yielded similarly at all three locations. Net returns were highest at all three locations with the glyphosate sequential system, with similar net returns obtained with glyphosate EPOST and glyphosate plus halosulfuron EPOST at two and one locations, respectively.

Weed Management in Soybean (Glycine max) with Preplant-Incorporated Herbicides and Cloransulam-Methyl

1999 ◽  
Vol 13 (2) ◽  
pp. 276-282 ◽  
Author(s):  
Shawn D. Askew ◽  
John W. Wilcut ◽  
Vernon B. Langston
Keyword(s):  
North Carolina ◽  
Glycine Max ◽  
Weed Control ◽  
Weed Management ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Net Returns ◽  
Pitted Morningglory ◽  
Prickly Sida ◽  
Smooth Pigweed

Cloransulam-methyl applied postemergence (POST) following various preplant-incorporated (PPI) herbicides was evaluated in four experiments for weed control in North Carolina soybean over a 2-yr period at three locations. Acifluorfen plus bentazon or chlorimuron alone applied POST injured soybean more than cloransulam-methyl when following any soil-applied herbicide. When following trifluralin PPI, cloransulam-methyl controlled common ragweed, entireleaf morningglory, and pitted morningglory comparable to acifluorfen plus bentazon or chlorimuron. Common lambsquarters and prickly sida control was higher when acifluorfen plus bentazon was applied POST following trifluralin PPI compared to trifluralin PPI followed by cloransulam-methyl or chlorimuron. Acifluorfen plus bentazon or chlorimuron POST controlled yellow nutsedge and smooth pigweed more than cloransulam-methyl POST when following trifluralin PPI. When trifluralin was applied PPI in mixtures with chlorimuron plus metribuzin, flumetsulam, or imazaquin, control of most species was similar regardless of POST treatment used. Soybean treated with cloransulam-methyl yielded 250 kg/ha more than treatments with chlorimuron when these herbicides followed trifluralin plus flumetsulam or trifluralin plus imazaquin. Net returns with different herbicide systems followed trends similar to soybean yield.

Weed Management in Cotton with CGA-362622, Fluometuron, and Pyrithiobac

2004 ◽  
Vol 18 (2) ◽  
pp. 268-276 ◽  
Author(s):  
Ian C. Burke ◽  
John W. Wilcut
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Systems ◽  
Cotton Lint ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Pitted Morningglory ◽  
Methylarsonic Acid ◽  
Prickly Sida ◽  
Smooth Pigweed

An experiment was conducted at five locations in North Carolina during 2000 and 2001 to evaluate weed control, crop injury, and cotton yield. Weed management systems included different combinations of pyrithiobac preemergence (PRE), fluometuron PRE, CGA-362622 postemergence (POST), pyrithiobac POST, and monosodium salt of methylarsonic acid (MSMA) plus prometryn applied late POST-directed (LAYBY). At Goldsboro in 2000, cotton was injured 74 to 78% by CGA-362622 POST when evaluated 4 to 7 d after treatment (DAT). Injury at Clayton, Goldsboro, and Lewiston in 2001 and Rocky Mount in 2000 was less than 16% 4 to 7 DAT with the same treatment and was not apparent by 62 DAT. CGA-362622 controlled common lambsquarters, common ragweed, Palmer amaranth, sicklepod, smooth pigweed, andIpomoeaspecies including entireleaf, ivyleaf, and pitted morningglory, and the addition of pyrithiobac to the herbicide system, either PRE or POST, increased control ofAmaranthusspecies, jimsonweed, and prickly sida. CGA-362622 did not control jimsonweed or prickly sida. Fluometuron PRE, pyrithiobac PRE, and MSMA plus prometryn LAYBY were beneficial for increasing weed control and cotton lint yields. Prometryn plus MSMA LAYBY increased control of common ragweed, entireleaf morningglory, jimsonweed, pitted morningglory, and smooth pigweed and provided higher cotton yields than similar systems without a LAYBY. The greatest weed control and greatest cotton lint yields required complete weed management systems that included a combination of PRE, POST, and LAYBY treatments.

Integration of a Brassicaceae Cover Crop with Herbicides in Plasticulture Tomato

2009 ◽  
Vol 23 (2) ◽  
pp. 280-286 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur
Keyword(s):  
Weed Control ◽  
Cover Crop ◽  
Fruit Yield ◽  
Palmer Amaranth ◽  
Marketable Yield ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Full Rate ◽  
Over The Top ◽  
Large Crabgrass

Weeds are a major constraint in tomato production, especially in the absence of methyl bromide. Field trials were conducted in 2006 and 2007 to evaluate the integrated use of a mustard ‘Caliente’ (a blend of brown and white mustard) cover crop with one-half and full rate PRE/POST herbicides for weed control and crop response in polyethylene-mulched tomato. Caliente was flail mowed and incorporated into the soil prior to forming beds. PRE herbicides were applied under polyethylene mulch, and POST herbicides were sprayed over the top of tomato. Full rates for S-metolachlor, halosulfuron, and trifloxysulfuron were 1,600, 27, and 7.9 g ai/ha, respectively. Caliente had no effect on weed control or tomato injury and yield. Except for large crabgrass control and tomato injury and yield, only the main effect of herbicide selection and application rate affected these parameters. Tomato injury was minimal (< 6%) from PRE- and POST-applied herbicides. S-metolachlor applied PRE provided 66% purple nutsedge, 67% yellow nutsedge, and 77% Palmer amaranth control at 4 wk after transplanting (WATP). S-metolachlor–treated plots at the full rate produced the highest marketable fruit yield among herbicide treatments, with jumbo fruit yield equivalent to the hand-weeded treatment. Trifloxysulfuron was the best POST-applied herbicide based on marketable yield and weed control. POST-applied trifloxysulfuron provided 41% purple nutsedge, 58% yellow nutsedge, and 55% Palmer amaranth control at 8 to 9 WATP. Halosulfuron applied PRE controlled purple and yellow nutsedge 70 and 78%, respectively, at 4 WATP, and POST-applied halosulfuron controlled purple nutsedge 74% and yellow nutsedge 78% at 8 to 9 WATP. Halosulfuron applied either PRE or POST failed to control Palmer amaranth and large crabgrass. Greater weed control and marketable tomato yield were achieved with full rates of herbicides. This research demonstrates no additional advantage of Caliente mustard when used with herbicides in tomato. None of the PRE or POST herbicides applied alone were sufficient to maintain season-long, broad-spectrum weed control and optimum marketable yield in tomato. Therefore, integration of PRE and POST herbicides at full rates is suggested.

Weed Management in Peanut (Arachis hypogaea) with Flumioxazin Preemergence

1999 ◽  
Vol 13 (3) ◽  
pp. 594-598 ◽  
Author(s):  
Shawn D. Askew ◽  
John W. Wilcut ◽  
John R. Cranmer
Keyword(s):  
Arachis Hypogaea ◽  
Weed Management ◽  
Chenopodium Album ◽  
Cyperus Esculentus ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Pitted Morningglory ◽  
Sida Spinosa ◽  
Prickly Sida ◽  
And Control

Flumioxazin plus metolachlor mixtures preemergence (PRE) were evaluated with or without postemergence (POST) herbicides for weed control and peanut (Arachis hypogaea) response in three North Carolina studies. Metolachlor PRE at 2.24 kg ai/ha controlled goosegrass (Eleusine indica) and yellow nutsedge (Cyperus esculentus) 93 and 80%, respectively, and control was not improved with flumioxazin or norflurazon. Metolachlor plus flumioxazin PRE at 0.07 or 0.11 kg ai/ha controlled common lambsquarters (Chenopodium album); entireleaf (Ipomoea hederaceavar.integriuscula), ivyleaf (I. hederacea), and pitted morningglory (I. lacunosa); and prickly sida (Sida spinosa) better than metolachlor plus norflurazon PRE at 1.34 kg ai/ha. Morningglories (Ipomoeaspp.) were controlled 77 and 86% with flumioxazin PRE at 0.07 and 0.11 kg/ha, respectively, and control was increased to nearly 100% with acifluorfen plus 2,4-DB or lactofen plus 2,4-DB POST. Peanut injury by flumioxazin and norflurazon was observed at one location in 1997; however, yields were not reduced. Peanut treated with metolachlor plus flumioxazin PRE at either rate yielded at least 3,750 kg/ha compared to 3,120 kg/ha with metolachlor plus norflurazon PRE or 1,320 kg/ha with metolachlor PRE.

Weed Management in Glufosinate-Resistant Corn (Zea mays)

1999 ◽  
Vol 13 (2) ◽  
pp. 324-333 ◽  
Author(s):  
A. Stanley Culpepper ◽  
Alan C. York
Keyword(s):  
North Carolina ◽  
Weed Management ◽  
Management Systems ◽  
Corn Yield ◽  
Common Lambsquarters ◽  
Late Season ◽  
Net Returns ◽  
Pitted Morningglory ◽  
Prickly Sida ◽  
Smooth Pigweed

An experiment was conducted at five locations in North Carolina to compare management systems utilizing glufosinate applied postemergence (POST) in glufosinate-resistant corn with standard systems of metolachlor plus atrazine preemergence (PRE) or nicosulfuron plus atrazine POST Glufosinate alone and both standard systems controlled common ragweed and prickly sida at least 98%, whereas sicklepod control was < 20% late in the season. Late-season control of common lambsquarters, smooth pigweed, pitted morningglory, and tall morningglory was generally less with glufosinate alone than with the standard systems. However, late-season control of common lambsquarters, smooth pigweed, pitted morningglory, tall morningglory, and sicklepod by mixtures of glufosinate plus atrazine was at least 99, 100, 89, 93, and 81%, respectively, and was equal to or greater than control by either standard. Broadleaf signalgrass, large crabgrass, and fall panicum were controlled similarly by glufosinate and the standards. Goosegrass control by glufosinate was similar to control by nicosulfuron plus atrazine, but it was less than control by metolachlor plus atrazine. Metolachlor applied PRE or atrazine mixed with glufosinate increased goosegrass control to that achieved with metolachlor plus atrazine. Mixing atrazine with glufosinate did not affect fall panicum control, but metolachlor PRE followed by glufosinate controlled fall panicum as well as the standards. Cultivation or ametryn applied at layby increased control when PRE or POST herbicides alone controlled weeds less than about 90%. Ametryn was generally more effective than cultivation. Glufosinate POST followed by ametryn at layby controlled sicklepod > 90% and other species > 95% late in the season. Corn yield and net returns were similar in the glufosinate and standard systems.

Postemergence Weed Control in Corn (Zea mays) with Nicosulfuron Combinations

1993 ◽  
Vol 7 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Anthony F. Dobbels ◽  
George Kapusta
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Field Studies ◽  
Corn Yield ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Growing Conditions

Field studies were conducted at Carbondale and Belleville, IL to evaluate weed control in corn with a total POST herbicide program. Nicosulfuron was applied at 24 and 35 g/ha alone and in combination with 2,4-D, dicamba, bromoxynil, bentazon, atrazine, and bentazon, bromoxynil, and dicamba plus atrazine. Nicosulfuron controlled 98 to 100% of giant foxtail both years at both locations. Control of giant foxtail was reduced when nicosulfuron at 24 g/ha was applied as a tank-mix with atrazine, and with bentazon, bromoxynil, or dicamba plus atrazine at Belleville in 1991. Also, bentazon plus atrazine with nicosulfuron at 35 g/ha reduced control of giant foxtail. Control of common lambsquarters, jimsonweed, and velvetleaf was dependent on nicosulfuron rate, companion herbicide, and growing conditions. Nicosulfuron alone or as a tank-mix with the companion herbicides controlled redroot pigweed 100% at both sites both years but control of yellow nutsedge was less than 50%. Corn yield was related to level of weed control obtained in most instances.

Glyphosate-Resistant Cotton (Gossypium hirsutum) Response and Weed Management with Trifloxysulfuron, Glyphosate, Prometryn, and MSMA

2006 ◽  
Vol 20 (1) ◽  
pp. 6-13 ◽  
Author(s):  
Walter E. Thomas ◽  
Tim T. Britton ◽  
Scott B. Clewis ◽  
Shawn D. Askew ◽  
John W. Wilcut
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Cotton Lint ◽  
Common Lambsquarters ◽  
Late Season ◽  
Pitted Morningglory ◽  
Glyphosate Formulation ◽  
Prickly Sida ◽  
Smooth Pigweed ◽  
Glyphosate Formulations

Field studies were conducted at three locations to evaluate glyphosate-resistant (GR) cotton response, weed control, and cotton lint yields to two formulations of glyphosate (diammonium salt– glyphosate and isopropylamine salt–glyphosate) and trifloxysulfuron applied early postemergence (EPOST) alone or to tank mixtures of trifloxysulfuron with each glyphosate formulation, with and without a late postemergence-directed (LAYBY) treatment of prometryn plus MSMA. Trifloxysulfuron and both formulations of glyphosate controlled common lambsquarters and pitted morningglory. Both glyphosate formulations provided equivalent control of common lambsquarters, goosegrass, pitted morningglory, prickly sida, and smooth pigweed. Trifloxysulfuron controlled smooth pigweed better than either glyphosate formulation but did not control goosegrass or prickly sida. Prometryn plus MSMA LAYBY improved late-season control of common lambsquarters, goosegrass, large crabgrass, and pitted morningglory for all EPOST systems and improved late-season smooth pigweed control for EPOST systems that did not include trifloxysulfuron. Cotton injury was 2% or less from both glyphosate formulations, while trifloxysulfuron injured ‘Deltapine 5415RR’ 7 to 16% at two locations. At a third location, trifloxysulfuron injured ‘Paymaster 1218RR/BG’ 24%, and when applied in mixture with either glyphosate formulation, injury increased to at least 72%. Cotton injury was transient at the first two locations and was not visually apparent 3 to 5 wk later. Cotton yield at the third location was reduced. High cotton yields reflected high levels of weed control.

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