Postemergence Weed Control in Acetolactate Synthase–Resistant Grain Sorghum

2010 ◽  
Vol 24 (3) ◽  
pp. 219-225 ◽  
Author(s):  
D. Shane Hennigh ◽  
Kassim Al-Khatib ◽  
Mitchell R. Tuinstra
Keyword(s):  
Field Experiments ◽  
Acetolactate Synthase ◽  
Grain Sorghum ◽  
Grass Species ◽  
Annual Grass ◽  
Metsulfuron Methyl ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Herbicide Treatments ◽  
Postemergence Herbicides

Postemergence herbicides to control grass weeds in grain sorghum are limited. Acetolactate synthase (ALS) –inhibiting herbicides are very effective at controlling many grass species in many crops; unfortunately, use of ALS-inhibiting herbicides is not an option in conventional grain sorghum because of its susceptibility to these herbicides. With the development of ALS-resistant grain sorghum, several POST ALS-inhibiting herbicides can be used to control weeds in grain sorghum. Field experiments were conducted in 2007 and 2008 to evaluate the efficacy of tank mixtures of nicosulfuron + rimsulfuron applied alone or in combination with bromoxynil, carfentrazone–ethyl, halosulfuron + dicamba, prosulfuron, 2,4-D, or metsulfuron methyl + 2,4-D. In addition, these treatments were applied with and without atrazine. Nicosulfuron + rimsulfuron controlled barnyardgrass, green foxtail, and giant foxtail 99, 86, and 91% 6 wk after treatment (WAT), respectively. A decrease in annual grass control was observed when nicosulfuron + rimsulfuron was tank mixed with some broadleaf herbicides, although the differences were not always significant. In addition, nicosulfuron + rimsulfuron controlled velvetleaf and ivyleaf moringglory 64 and 78% 6 WAT, respectively. Control of velvetleaf was improved when nicosulfuron + rimsulfuron was tank mixed with all broadleaf herbicides included in this study with the exception of atrazine, bromoxynil, and prosulfuron + atrazine. Control of ivyleaf morningglory was improved when nicosulfuron + rimsulfuron was tank mixed with all of the herbicides included in this study with the exception of metsulfuron methyl + 2,4-D. Weed populations and biomass were lower when nicosulfuron + rimsulfuron were applied with various broadleaf herbicides than when it was applied alone. Grain sorghum yield was greater in all herbicide treatments than in the weedy check, with the highest grain yield from nicosulfuron + rimsulfuron + prosulfuron. This research showed that postemergence application of nicosulfuron + rimsulfuron effectively controls grass weeds, including barnyardgrass, green foxtail, and giant foxtail. The research also showed that velvetleaf and ivyleaf morningglory control was more effective when nicosulfuron + rimsulfuron were applied with other broadleaf herbicides.

Weed Efficacy Evaluations for Bromoxynil, Glufosinate, Glyphosate, Pyrithiobac, and Sulfosate

2004 ◽  
Vol 18 (2) ◽  
pp. 443-453 ◽  
Author(s):  
Jerry L. Corbett ◽  
Shawn D. Askew ◽  
Walter E. Thomas ◽  
John W. Wilcut
Keyword(s):  
Field Trials ◽  
Grass Species ◽  
Annual Grass ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Herbicide Treatments ◽  
Rate Controlled ◽  
Prickly Sida

Thirteen field trials were conducted in 1999 and 2000 to evaluate postemergence (POST) weed control with single applications of bromoxynil at 420 or 560 g ai/ha, glufosinate at 291 or 409 g ai/ha, glyphosate at 1,120 g ai/ha, pyrithiobac at 36 or 72 g ai/ha, or sulfosate at 1,120 g ai/ha. Additional treatments evaluated included two applications with glufosinate at both rates in all possible combinations, two applications of glyphosate, and two applications of sulfosate. Weeds were 2 to 5 cm or 8 to 10 cm tall for annual grass and broadleaf weeds whereas yellow nutsedge and glyphosate-resistant corn were 8 to 10 cm tall. All herbicide treatments controlled 2- to 5-cm common cocklebur, Florida beggarweed, jimsonweed, ladysthumb smartweed, Pennsylvania smartweed, pitted morningglory, prickly sida, redroot pigweed, smooth pigweed, and velvetleaf at least 90%. All herbicide treatments except pyrithiobac at either rate controlled 2- to 5-cm common lambsquarters, common ragweed, and tall morningglory at least 90%; pyrithiobac at the lower rate was the only treatment that failed to control entireleaf and ivyleaf morningglory at least 90%. Bromoxynil and pyrithiobac at either rate controlled 2- to 5-cm sicklepod 33 to 68% whereas glufosinate, glyphosate, and sulfostate controlled ≥99%. Glyphosate and sulfosate applied once or twice controlled hemp sesbania less than 70% and volunteer peanut less than 80%. Bromoxynil and pyrithiobac were the least effective treatments for control of annual grass species and bromoxynil controlled Palmer amaranth less than 80%. Glufosinate controlled broadleaf signalgrass, fall panicum, giant foxtail, green foxtail, large crabgrass, yellow foxtail, seedling johnsongrass, Texas panicum, and glyphosate-resistant corn at least 90% but controlled goosegrass less than 60%. Glyphosate and sulfosate controlled all grass species except glyphosate-resistant corn at least 90%. In greenhouse research, goosegrass could be controlled with glufosinate POST plus a late POST-directed treatment of prometryn plus monosodium salt of methylarsonic acid.

Annual Grass Control in Alfalfa (Medicago sativa) with Postemergence Graminicides

1992 ◽  
Vol 6 (4) ◽  
pp. 938-948 ◽  
Author(s):  
Chester L. Foy ◽  
Harold L. Witt
Keyword(s):  
Medicago Sativa ◽  
Field Experiments ◽  
Annual Grass ◽  
Giant Foxtail ◽  
Herbicide Treatments ◽  
Highly Effective ◽  
Annual Grasses ◽  
Large Crabgrass

Field experiments were conducted during 1982 to 1988 in Virginia to evaluate BAS 517, CGA 82725, clethodim, cloproxydim, fenoxaprop, fluazifop, fluazifop-P, haloxyfop, paraquat, quizalofop, SC-1084, sethoxydim, sethoxydim plus thifensulfuron, and terbacil for control of annual grasses in alfalfa. Herbicides were applied to alfalfa and grasses 2 to 30 cm in height after the first and/or second cuttings. Overall, the herbicides were highly effective in controlling fall panicum, giant foxtail, barnyardgrass, and large crabgrass. Alfalfa yields were not increased with herbicide treatments in several experiments. Only paraquat, applied later than recommended after cutting in one experiment, and sethoxydim plus thifensulfuron at one location reduced alfalfa yields.

Synergistic Mixtures of Sethoxydim and Fluazifop on Annual Grass Weeds

1991 ◽  
Vol 5 (2) ◽  
pp. 310-316 ◽  
Author(s):  
K. Neil Harker ◽  
P. Ashley O'Sullivan
Keyword(s):  
Field Experiments ◽  
Grass Species ◽  
Research Station ◽  
Wild Oat ◽  
Annual Grass ◽  
Herbicide Application ◽  
Additive Interaction ◽  
Application Rates ◽  
Green Foxtail ◽  
Negative Environmental Impact

Greenhouse and field experiments were conducted at the Lacombe Research Station to evaluate mixtures of sethoxydim and fluazifop on green foxtail, wild oat, wheat, and barley in canola. In both environments the two herbicides interacted on the grass species in a synergistic manner. Many of the observed responses to mixtures of sethoxydim and fluazifop were 100% greater than those expected assuming an additive interaction between the herbicides. Mixtures with at least 80 g ha-1of sethoxydim and 80 g ha-1of fluazifop controlled more than 90% of green foxtail, wild oat, wheat, and barley under field conditions. These experiments indicate that the sethoxydim/fluazifop mixture is both complementary and synergistic. The mixture may allow reduced herbicide application rates and therefore reduced herbicide costs and less potential for negative environmental impact.

Influence of Temperature, Rainfall, Grass Species, and Growth Stage on Efficacy of Fluazifop

1990 ◽  
Vol 4 (2) ◽  
pp. 349-355 ◽  
Author(s):  
Reid J. Smeda ◽  
Alan R. Putnam
Keyword(s):  
Air Temperature ◽  
Growth Stage ◽  
Field Experiments ◽  
Grass Species ◽  
Optimum Control ◽  
Free Interval ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Growth Room ◽  
Large Crabgrass

Field experiments were initiated to determine the efficacy of fluazifop as influenced by growth stage for green, yellow, and giant foxtail, large crabgrass, and Japanese millet. Additionally, the influence of air temperature and simulated rainfall on fluazifop efficacy for green foxtail and Japanese millet was determined by greenhouse and growth-room experiments. In both 1983 and 1984, fluazifop activity was reduced as the growth stage increased from 3- to 5- to 7-leaf for all species. Significant differences among species in susceptibility to fluazifop were evident with the descending order of tolerance: green foxtail > large crabgrass > yellow foxtail > giant foxtail > Japanese millet. Increasing the air temperature from 18 to 30 C reduced fluazifop control of green foxtail at herbicide rates less than 0.14 kg ai/ha but did not affect Japanese millet. A 1- to 2-h rain-free interval was required for optimum control of green foxtail and Japanese millet at 0.07 kg/ha fluazifop; the interval was reduced to 45 and 15 min, respectively, when fluazifop rates were 0.14 kg/ha. The longer rain-free interval required for optimum control of green foxtail compared to Japanese millet may reflect a slower rate of herbicide absorption in green foxtail.

Interference of Three Annual Grasses with Grain Sorghum (Sorghum bicolor)

1990 ◽  
Vol 4 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Brenda S. Smith ◽  
Don S. Murray ◽  
J. D. Green ◽  
Wan M. Wanyahaya ◽  
David L. Weeks
Keyword(s):  
Linear Regression ◽  
Grain Yield ◽  
Field Experiments ◽  
Grain Sorghum ◽  
Grass Species ◽  
Row Spacing ◽  
Yield Data ◽  
Weed Density ◽  
Annual Grasses ◽  
Wide Row Spacing

Barnyardgrass, large crabgrass, and Texas panicum were evaluated in field experiments over 3 yr to measure their duration of interference and density on grain sorghum yield. When grain yield data were converted to a percentage of the weed-free control, linear regression predicted a 3.6% yield loss for each week of weed interference regardless of year or grass species. Grain sorghum grown in a narrow (61-cm) row spacing was affected little by full-season interference; however, in wide (91-cm) rows, interference increased as grass density increased. Data from the wide-row spacing were described by linear regression following conversion of grain yield to percentages and weed density to log10. A separate nonlinear model also was derived which could predict the effect of weed density on grain sorghum yield.

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

2018 ◽  
Vol 32 (4) ◽  
pp. 364-370 ◽  
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.

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

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.

Effects of Various Adjuvants on Sethoxydim Activity

1992 ◽  
Vol 6 (4) ◽  
pp. 865-870 ◽  
Author(s):  
K. Neil Harker
Keyword(s):  
No Value ◽  
Ammonium Sulphate ◽  
Field Experiments ◽  
Grass Species ◽  
Research Station ◽  
Wild Oat ◽  
Green Foxtail

Field experiments were conducted at the Lacombe Research Station from 1989 to 1991 to determine the influence of various adjuvants on sethoxydim activity. In all experiments sethoxydim was applied at 100 g ai ha-1to green foxtail, wheat, wild oat, and barley seeded in a canola crop. Of the four grass species, green foxtail was the most susceptible and barley was the least susceptible to sethoxydim. CC 16255 was the most effective adjuvant followed by either of two sources of ammonium sulphate (liquid or granular) and then Merge. Liquid and granular forms of ammonium sulphate were equally effective in enhancing sethoxydim activity. Several other adjuvants, including Enhance, Savol, and XE 1167, were moderately effective in the enhancement of sethoxydim activity. Adding Canplus 411 to Merge was not usually beneficial, but additions of Canplus 411 to Enhance often increased sethoxydim activity compared with sethoxydim and Enhance alone. Agral 90 and LI-700 were of little or no value as adjuvants with sethoxydim.

scholarly journals Weed seed bank emergence across the Corn Belt

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Frank Forcella ◽  
Robert G. Wilson ◽  
Jack Dekker ◽  
Robert J. Kremer ◽  
John Cardina ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Field Experiments ◽  
Soil Depth ◽  
Early Spring ◽  
Temperature And Precipitation ◽  
Secondary Dormancy ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Viable Seeds ◽  
Common Purslane

Field experiments, conducted from 1991 to 1994, generated information on weed seedbank emergence for 22 site-years from Ohio to Colorado and Minnesota to Missouri. Early spring seedbank densities were estimated through direct extraction of viable seeds from soil cores. Emerged seedlings were recorded periodically, as were daily values for air and soil temperature, and precipitation. Percentages of weed seedbanks that emerged as seedlings were calculated from seedbank and seedling data for each species, and relationships between seedbank emergence and microclimatic variables were sought. Fifteen species were found in 3 or more site-years. Average emergence percentages (and coefficients of variation) of these species were as follows: giant foxtail, 31.2 (84%); velvetleaf, 28.2 (66); kochia, 25.7 (79); Pennsylvania smartweed, 25.1 (65); common purslane, 15.4 (135); common ragweed, 15.0 (110); green foxtail, 8.5 (72); wild proso millet, 6.6 (104); hairy nightshade, 5.2 (62); common sunflower, 5.0 (26); yellow foxtail, 3.4 (67); pigweed species, 3.3 (103); common lambsquarters, 2.7 (111); wild buckwheat, 2.5 (63), and prostrate knotweed, 0.6 (79). Variation among site-years, for some species, could be attributed to microclimate variables thought to induce secondary dormancy in spring. For example, total seasonal emergence percentage of giant foxtail was related positively to the 1st date at which average daily soil temperature at 5 to 10 cm soil depth reached 16 C. Thus, if soil warmed before mid April, secondary dormancy was induced and few seedlings emerged, whereas many seedlings emerged if soil remained cool until June.

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.

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