Field Performance of Glyphosate as Influenced by Selected Adjuvants and a Low-Volume, Air-Assisted Sprayer

2004 ◽  
Vol 18 (2) ◽  
pp. 458-463
Author(s):  
Wilson H. Faircloth ◽  
Michael G. Patterson ◽  
Sidney B. Belcher ◽  
Jason C. Sanders ◽  
Daniel O. Stephenson
Keyword(s):  
Field Performance ◽  
Field Studies ◽  
Application Rate ◽  
Visual Control ◽  
Agricultural Experiment Station ◽  
Herbicide Application ◽  
Control Data ◽  
Agricultural Experiment ◽  
Low Volume ◽  
Biomass Reduction

Field studies were conducted at the Alabama Agricultural Experiment Station near Shorter, AL, from 1998 to 2000 to evaluate six commercial spray adjuvants and their effects on glyphosate applied to cotton with an air-assisted sprayer. Each adjuvant was evaluated with a conventional sprayer calibrated to deliver 94 L/ha solution and a low-volume, air-assisted sprayer calibrated to deliver 19 L/ha solution. Glyphosate was applied to two-leaf pitted and entireleaf morningglory growing in glyphosate-resistant cotton. Visual control of pitted and entireleaf morningglory was more dependent on the rate of herbicide application than on a particular adjuvant or sprayer, with glyphosate at 0.42 kg ae/ha providing 70% control 21 d after treatment. Pitted and entireleaf morningglory biomass measurements generally reflected visual control data. Ammonium sulfate and formulated glyphosate consistently gave the highest visual control and the greatest biomass reduction. Glyphosate application rate was more important than adjuvant addition or sprayer type, with the higher rates of application providing greater control. No differences in weed control were observed between spray systems; therefore, air-assisted sprayers may be used on a field-scale basis with consistent and adequate results.

scholarly journals Interaction of dicamba, fluthiacet-methyl, and glyphosate for control of velvetleaf (Abutilon theopharsti) in dicamba/glyphosate-resistant soybean

2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala
Keyword(s):  
United States ◽  
Field Experiments ◽  
The United States ◽  
Application Rate ◽  
Herbicide Application ◽  
Soybean Yield ◽  
Agronomic Crops ◽  
Split Plot ◽  
Main Plot ◽  
Biomass Reduction

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.

scholarly journals Evaluation of diquat for postemergence weed control in pumpkin (Cucurbita moschata)

1969 ◽  
Vol 72 (2) ◽  
pp. 285-290
Author(s):  
Luis Almodóvar-Vega ◽  
Manuel Díaz-Rivera ◽  
Nelson Semidey-Laracuente
Keyword(s):  
Toxic Effect ◽  
Weed Control ◽  
Clay Soil ◽  
Cucurbita Moschata ◽  
Agricultural Experiment Station ◽  
Herbicide Application ◽  
Promising Candidate ◽  
Plot Yield ◽  
Broad Leaf ◽  
Agricultural Experiment

In 1982, the bipyridilium herbicides diquat [6,7-dihydrodipyrido (1,2- :2;i-c) pyrazinediium ion] at 0.56, 1.12 and 2.24 kg ai/ha, and paraquat [1, 1-dimethyl-4,4' -bipyridinium ion] at 2.24 kg ai/ha were evaluated for postemergence control of weeds in pumpkin cv. Borinquen (Cucurbita moschata (Duchesne) Poir). The experiment was established in Fraternidad clay soil, a Vertisol at the Lajas Substation, Agricultural Experiment Station. No statistical differences (P=0.05) in yield were detected among the hand-weeded plots (25,580 kg/ha), diquat treated plots (23,296 kg/ha), and paraquat treated plots (27,341 kg/ha). Significant differences in plot yield were observed among paraquat 2.24 kg rate treatment, diquat at the lower rates, and the non-weeded plots. Yields were 0.56 kg diquat (17,172 kg/ha), 1.12 kg diquat (19,551 kg), and non weeded check (10,243 kg/ha). All rates of herbicides provided 100% control of Ipomoea tillacea L.; the higher rates also controlled over 85% Euphorbia heterophylla. Control of grass weeds was inefficient (10% or less) with diquat sprays 1 month after the second herbicide application. Nevertheless, diquat seems to be a promising candidate herbicide for postemergence weed control in pumpkin since it efficiently controlled broad leaf weeds with less toxic effect on applicators than paraquat.

Effect of glyphosate application timings and methods on glyphosate-resistant cotton

Weed Science ◽  
2004 ◽  
Vol 52 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Ryan P. Viator ◽  
Phil H. Jost ◽  
Scott A. Senseman ◽  
J. T. Cothren
Keyword(s):  
Topical Application ◽  
Yield Loss ◽  
Field Studies ◽  
Agricultural Experiment Station ◽  
Texas Agricultural Experiment Station ◽  
Leaf Stage ◽  
Experiment Station ◽  
Boll Weight ◽  
Agricultural Experiment ◽  
Over The Top

Under certain conditions, application of glyphosate to glyphosate-resistant (GR) cotton can lead to fruit shedding and yield reductions. Field studies were conducted at the Texas Agricultural Experiment Station using GR cotton, cv. ‘DeltaPine 5690RR’, to determine if application method and timing affect cotton fruit retention. Glyphosate at 1.12 kg ai ha−1was precisely postdirected (PD), postdirected with 25% foliage coverage (PDFC), or applied over the top (OT) at the 8- or 18-leaf stage after an initial topical application of 1.12 kg ha−1glyphosate at the four-leaf stage. In one of the years of this study, 8 PD, 18 PDFC, and 18 OT reduced yield. In 1999 and 2000, 8 PDFC and 8 OT applications of glyphosate caused yield loss, mainly due to lower mean boll weight. Glyphosate applied topically at the eight-leaf stage also affected the Position 1 boll retention throughout the plant in both years. Glyphosate contact with leaves and stems should be avoided when applying glyphosate after the four-leaf stage to prevent possible yield loss.

Growth Response of Wild Poinsettia (Euphorbia heterophylla) Following Foliar Herbicide Applications

1993 ◽  
Vol 7 (1) ◽  
pp. 190-195 ◽  
Author(s):  
Teresa S. Willard ◽  
James L. Griffin
Keyword(s):  
Field Study ◽  
Weed Control ◽  
Seed Production ◽  
Growth Response ◽  
Field Studies ◽  
Lateral Branch ◽  
Herbicide Application ◽  
Branch Number ◽  
Untreated Check ◽  
Biomass Reduction

Greenhouse and field studies were conducted to characterize wild poinsettia growth response to imazaquin (140 g ai ha−1), fomesafen and acifluorfen (420 g ai ha−1), and chlorimuron (9 g ai ha−1) applied at 5 to 7 cm (POST1), 8 to 10 cm (POST2), and 15 to 20 cm (POST3). Based on reductions in weed height and lateral branch number 28 DAT, wild poinsettia was controlled more effectively in both greenhouse and field studies for all herbicides applied at POST1 than at POST3. In the greenhouse studies, reduction in wild poinsettia biomass with the herbicides 28 DAT was similar when applied at POST1 and POST2 and, with the exception of chlorimuron, was higher at POST2 than at POST3. In the field study, weed biomass reduction measured approximately 4 mo after herbicide application was higher for imazaquin, acifluorfen, and chlorimuron applied at POST2 than at POST1. Wild poinsettia biomass was reduced more with imazaquin applied at POST3 than at POST1. Increased lateral branch production, indicative of decreased weed control, was often manifested in higher seed production per plant. With application of all herbicides at POST3 seed production was equal to the untreated check.

Response of Sweetpotato Cultivars to Linuron Rate and Application Time

2018 ◽  
Vol 32 (6) ◽  
pp. 665-670 ◽  
Author(s):  
Shawn C. Beam ◽  
Katherine M. Jennings ◽  
Sushila Chaudhari ◽  
David W. Monks ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Field Studies ◽  
Application Rate ◽  
Application Time ◽  
Herbicide Application ◽  
Application Rates

AbstractField studies were conducted in 2015 and 2016 in North Carolina to determine the response of ‘Covington’ and ‘Murasaki-29’ sweetpotato cultivars to four rates of linuron (420, 560, 840, and 1,120 g ai ha–1) alone or withS-metolachlor (803 g ai ha–1) applied 7 or 14 d after transplanting (DAP). Injury (chlorosis/necrosis and stunting) to both cultivars was greater when linuron was applied withS-metolachlor as compared to linuron applied alone. Herbicide application at 14 DAP caused greater injury (chlorosis/necrosis and stunting) to both cultivars than when applied at 7 DAP. At 4 wk after treatment (WAT), stunting of Covington and Murasaki-29 (hereafter Murasaki) from linuron at 420 to 1,120 g ha–1increased from 27% to 50% and 25% to 53%, respectively. At 7 or 8 WAT, crop stunting of 8% or less and 0% was observed in Covington and Murasaki, respectively, regardless of application rate and timing. Murasaki root yields were similar in the linuron alone or withS-metolachlor treatments, and were lower than the nontreated check. In 2016, no. 1 and marketable sweetpotato yields of Covington were similar for the nontreated check, linuron alone, or linuron plusS-metolachlor treatments, but not in 2015. Decreases in no. 1 and marketable root yields were observed when herbicides were applied 14 DAP compared to 7 DAP for Covington in 2015 and for Murasaki in both years. No. 1 and marketable yields of Covington were similar for 420 to 1,120 g ha–1linuron and nontreated check except marketable root yields in 2015. No. 1 and marketable sweetpotato yields of Murasaki decreased as application rates increased.

scholarly journals Performance of paraquat and sethoxydim in arracacha

1969 ◽  
Vol 85 (1-2) ◽  
pp. 63-68
Author(s):  
María de L. Lugo ◽  
Alvaro Acosta
Keyword(s):  
Puerto Rico ◽  
Weed Control ◽  
Field Experiments ◽  
University Of Puerto Rico ◽  
Agricultural Experiment Station ◽  
Herbicide Application ◽  
Agricultural Experiment ◽  
Late Application ◽  
Hand Weeding ◽  
The University

Field experiments were conducted at the Adjuntas Agricultural Experiment Station of the University of Puerto Rico during 1996 and 1998 to evaluate the efficacy of the herbicides paraquat and sethoxydim on arracacha. In 1996, no differences were found among the treatments for weed control four weeks after the first and second herbicide applications. Weed control ranged from 72% (two applications of sethoxydim) to 87% (hand weeding) at four weeks after herbicide application, and from 43% (one application of paraquat) to 97% (two applications of paraquat) at four weeks after the second herbicide application. There were no significant differences in yield between treatments with two applications of paraquat and that of hand weeding.The lowest yield (7,632 kg/ha) was obtained when sethoxydim was applied once. In the 1998 experiment, no differences in weed control were found among treatments at four weeks after the first herbicide application; weed control ranged from 81% (two applications of sethoxydim) to 98% (hand weeding). When rated at four weeks after the second herbicide application, the lowest weed control (84%) was obtained with one late application of paraquat. There were no significant differences in yield and number of corms per hectare among treatments.

scholarly journals Reproduction and biomarker responses of Eisenia fetida after exposure to imidacloprid in biochar-amended soil

Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo
Keyword(s):  
Eisenia Fetida ◽  
Field Studies ◽  
Application Rate ◽  
Land Application ◽  
Acetylcholinesterase Inhibition ◽  
Beneficial Effects ◽  
Pesticide Pollution ◽  
The One ◽  
The Impact ◽  
Amended Soil

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.

scholarly journals Yield, germination and herbicide residue in seeds of preharvest desiccated wheat

2018 ◽  
Vol 40 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Lais Tessari Perboni ◽  
Dirceu Agostinetto ◽  
Leandro Vargas ◽  
Joanei Cechin ◽  
Renan Ricardo Zandoná ◽  
...  
Keyword(s):  
Wheat Yield ◽  
Application Rate ◽  
Application Time ◽  
Herbicide Application ◽  
Herbicide Residue ◽  
Application Rates ◽  
Weight Yield ◽  
Time Periods ◽  
Dough Stage ◽  
Wheat Seeds

Abstract: The goals of this study were to evaluate herbicide application rates at different timings for preharvest desiccation of wheat (Trial 1), as well as to evaluate the effect of the timing of herbicide desiccation at preharvest and harvest timing (Trial 2) on yield, germination, and herbicide residue in wheat seed. In Trial 1, treatments consisted of two application rates of glufosinate, glyphosate, paraquat, or paraquat+diuron and a control without application; application time periods were in the milk grain to early dough stage, soft dough to hard dough stage, and hard dough stage. In Trial 2, treatments consisted of different application time periods (milk grain to early dough stage, and soft dough to hard dough stage), different herbicides (glufosinate, 2,4-D+glyphosate, and untreated control), and different harvest times (5, 10 and 15 days after herbicide application). One thousand seeds weight, yield, first and final germination count, and herbicide residue on seeds were evaluated. Preharvest desiccation with paraquat, glufosinate, and 2,4-D+glyphosate at the milk grain to early dough stage reduces wheat yield. Regardless of the herbicide and application rate, application in the milk grain to early dough stage and soft dough to hard dough stage provides greater germination of wheat seeds, except at the lower dose of paraquat. Systemic herbicides accumulate more in wheat seeds.

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