Weed Control Using Reduced Rates of Postemergence Herbicides in Narrow and Wide Row Soybean

jpa ◽  
1997 ◽  
Vol 10 (3) ◽  
pp. 431-437 ◽  
Author(s):  
James A. Mickelson ◽  
Karen A. Renner
2007 ◽  
Vol 8 (1) ◽  
pp. 4 ◽  
Author(s):  
J. A. Kendig ◽  
R. L. Nichols ◽  
G. A. Ohmes

The current dominant weed control program in cotton relies heavily on glyphosate. Typical glyphosate-based weed control programs require repeat applications. A residual herbicide might reduce the number of herbicide applications needed, and potentially reduce costs. Residual herbicides that can be used postemergence in cotton are limited in number, and there are few studies evaluating the response of cotton to over-the-top application of herbicides. A greenhouse study evaluated response of cotton to fluometuron, propazine, metolachlor, pyrithiobac, and glyphosate. Most of these herbicides caused minimal crop injury; however, fluometuron and propazine caused significant visual injury when applied over-the-top at the cotyledon and two-leaf stages, but less injury when applied preemergence. Accepted for publication 5 July 2007. Published 8 November 2007.


2006 ◽  
Vol 20 (3) ◽  
pp. 551-557 ◽  
Author(s):  
Timothy L. Grey ◽  
Paul L. Raymer ◽  
David C. Bridges

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.


Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 390-397 ◽  
Author(s):  
Ivan Sartorato ◽  
Antonio Berti ◽  
Giuseppe Zanin ◽  
Claudio M. Dunan

The introduction of herbicide-resistant crops and postemergence herbicides with a wide action spectrum shifted the research focus from how to when crops should be treated. To maximize net return of herbicide applications, the evolution of weed–crop competition over time must be considered and its effects quantified. A model for predicting the yield trend in relation to weed removal time, considering emergence dynamics and density, was tested on data from glyphosate-resistant soybean grown in cropping systems in Italy and Argentina. Despite an ample variation of weed emergence dynamics and weed load in the four trials, the model satisfactorily predicted yield loss evolution. The estimated optimum time for weed control (OTWC) varied from about 18 d after soybean emergence in Argentina to 20 to 23 d in Italy, with time windows for spraying ranging from 14 to 28 d. Within these limits a single glyphosate application ensures good weed control at low cost and avoids side effects like the more probable unfavorable weed flora evolution with double applications and the presence of residues in grains. Despite the apparent simplicity of weed control based on nonselective herbicides, the study outlines that many variables have to be considered to optimize weed management, particularly for the time evolution of the infestation and, subsequently, a proper timing of herbicide application.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
W. James Grichar ◽  
Peter A. Dotray ◽  
Calvin L. Trostle

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.


2010 ◽  
Vol 20 (4) ◽  
pp. 772-777 ◽  
Author(s):  
Orville C. Baldos ◽  
Joseph DeFrank ◽  
Glenn Sakamoto

Field experiments were conducted to assess the tolerance of seashore dropseed (Sporobolus virginicus) to pre- and postemergence herbicides labeled for roadside right-of-way use. Dithiopyr (0.25 and 0.50 lb/acre a.i.), trifluralin + isoxaben (2.0 + 0.5 and 4.0 + 1.0 lb/acre a.i.), oxyfluorfen (0.25 and 0.50 lb/acre a.i.), oxadiazon (2.0 and 4.0 lb/acre a.i.), and granular table salt (99% sodium chloride, 1% sodium silicoaluminate; 83% of particles 0.5–0.25 mm in diameter, 400 lb/acre a.i.) were applied at 2 and 84 days after transplanting (DAT). Pre-emergence weed control with crop response measures as visual foliar injury ratings and aboveground biomass accumulation were recorded 38 days after the second application of herbicides (DAH2). Crop response to postemergence herbicides aminopyralid (1.10 lb/acre a.i.), triclopyr (3.0 lb/acre a.i.), a prepackaged mix of carfentrazone + (4-chloro-2-methylphenoxy)acetic acid + mecoprop + dicamba (0.02 + 1.11 + 0.22 + 0.11 lb/acre a.i.), and sulfosulfuron (0.06 lb/acre a.i.) applied at 70 and 98 DAT included visual foliar injury ratings and aboveground biomass accumulation at 28 DAH2. Although all pre-emergence herbicides (except table salt) exhibited acceptable weed control ratings, only oxadiazon and oxyfluorfen showed exceptional weed control and safety. The postemergence herbicide sulfosulfuron was the least injurious to seashore dropseed. The mixture of carfentrazone + (4-chloro-2-methylphenoxy)acetic acid + mecoprop + dicamba and triclopyr were the most injurious to seashore dropseed and should only be used as a directed spray treatment. An unintended overapplication of aminopyralid was phytotoxic, but it did not lead to complete plant death at 28 DAH2. These data identified oxadiazon, oxyfluorfen, and sulfosulfuron as safe and effective for establishing transplanted seashore dropseed plugs.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 554C-554
Author(s):  
Yahya K. Al-Hinai ◽  
Teryl R. Roper

This experiment was conducted to determine temporal and spatial weed management characteristics for tart cherry orchards. Annual ryegrass and lambsquarter were planted in tree rows of a 14-year-old tart cherry orchard. Vegetation was controlled with nonresidual herbicides (Gramoxone + B-1956) either all season, May, June, July, August, before harvest, after harvest, or not controlled. Shoot growth measurements showed significantly more growth by trees without weed competition during the entire season, May, June, and before harvest compared to the weedy control and postharvest, July, or August treatments. Weedy early season plots reduced the shoot growth by half. All season, before harvest, May, and June weed-free plots showed higher amounts of leaf N compared with weedy controls or late-season treatments. Early season weed control is more important than late season. Vegetation-free areas of 0, 2, 3, and 4 m2 were maintained during 1998 by postemergence herbicides. Tissue analysis showed higher N concentration in leaves with vegetation controlled to 2 m2 or more compared to the weedy control. The critical vegetation free area for young cherry trees is between 0 and 2 m2.


HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1823-1825 ◽  
Author(s):  
Katie J. Kammler ◽  
S. Alan Walters ◽  
Bryan G. Young

Field studies were conducted to evaluate postemergence combinations of halosulfuron plus sethoxydim or clethodim with various adjuvants for effects on jack-o-lantern pumpkin (Cucurbita pepo L.) injury and yields and control of large [Digitaria sanguinalis (L.) Scop.] and smooth crabgrass [D. ischaemum (Schreb. ex Schweig.) Schreb. ex Muhl.]. Halosulfuron caused 27% and 14% pumpkin injury at 28 d after postemergence treatment (DAPT) in 2004 and 2005, respectively. Tank-mixing sethoxydim or clethodim with halosulfuron did not increase pumpkin injury compared with halosulfuron alone. Pumpkin injury from sethoxydim and clethodim alone at 28 DAPT ranged from 19% to 23% in 2004, but was only 7% to 8% in 2005. The addition of oil-based adjuvants to halosulfuron did not affect pumpkin injury compared with using a nonionic surfactant (NIS). The tank mixture of halosulfuron and sethoxydim did not affect crabgrass control regardless of adjuvant. However, the addition of halosulfuron to clethodim plus NIS reduced control of crabgrass from 89% to 77% at 28 DAPT. Crabgrass control was unaffected by the addition of halosulfuron to clethodim with crop oil concentrate (COC) or a NIS/COC blend. None of the herbicide treatments provided pumpkin yield (fruit no./ha) similar to the weed-free control. The pumpkin yield of treatments using postemergence herbicides was at least 50% less than the weed-free treatment. These low pumpkin yields were most likely the result of the combination of pumpkin injury from the herbicide applications and insufficient weed control.


2005 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Richard N. Arnold ◽  
Dan Smeal ◽  
Michael K. O'Neill

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 889-891 ◽  
Author(s):  
P. Ashley O'Sullivan

Field experiments were conducted for 2 yr to determine the influence of picloram (4-amino-3,5,6-trichloropicolinic acid) and a commercial mixture of picloram plus 2,4-D [(2,4-dichlorophenoxy)acetic acid] (1:16, w/w) on control of wild oats (Avena fatua L. # AVEFA) with four postemergence herbicides. The phytotoxicity to wild oats of barban (4-chloro-2-butynyl m-chlorocarbanilate) or difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium) in 1981 and diclofop {2-[4-(2,4-dichlorophenoxy)-phenoxy] propanoic acid} or flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine] in 1981 and 1982 was reduced when these herbicides were applied in a mixture with picloram plus 2,4-D. Consequently, the use of these mixtures for broad-spectrum weed control in one spray operation is not recommended. Picloram applied at a rate equivalent to the amount present in the picloram plus 2,4-D mixture did not influence the control of wild oats obtained with any herbicide, indicating that the antagonism was due to the 2,4-D component of the picloram plus 2,4-D mixture.


Agriculture ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 163
Author(s):  
Robert Idziak ◽  
Zenon Woznica

Field trials were conducted with preemergence dimethanamid-P + pendimethalin (D + P; 850 + 1000 g·ha−1) and reduced rates (637.5 + 750 g·ha−1 and 452 + 500 g·ha−1, 75% and 50% of label rate), followed by strongly reduced rates of postemergence herbicides nicosulfuron + rimsulfuron + dicamba (N + R + D; 4 + 15.6 + 93.5 g·ha−1, 50%), tembotrione (T; 33 g·ha−1, 50%), mesotrione + nicosulfuron (M + N; 37.5 + 15 g·ha−1, 50%), foramsulfuron + iodosulfuron (F + J; 7.5 + 0.25 g·ha−1, 20%), and nikosulfuron (N; 15 g·ha−1, 33%) applied with methylated seed oil (MSO; 1.0 L·ha−1) and ammonium nitrate (AMN; 2 kg·ha−1) on 3–5 leaves of maize to assess weed control, grain yield, and economic net return. Reduced rate of soil-applied herbicide followed by reduced rates of any postemergence herbicides applied with adjuvants was the most efficacious weed control program, provided the highest grain yield of maize and similar or higher economic net return, despite 44 to 48% lower herbicide input than the program based on soil-applied herbicide mixture only. It brings not only notable economic benefits but also less negative impact on the environment.


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