scholarly journals Pelargonic Acid for Weed Control in Organic Vidalia® Sweet Onion Production

2014 ◽  
Vol 24 (6) ◽  
pp. 696-701 ◽  
Author(s):  
Wiley Carroll Johnson ◽  
Jerry W. Davis
Keyword(s):  
Weed Control ◽  
Winter Season ◽  
Field Trials ◽  
Pelargonic Acid ◽  
Yield Response ◽  
Clove Oil ◽  
Cool Season ◽  
Control Efficacy ◽  
Natural Sources ◽  
Main Effects

Cultivation using a tine weeder is a proven means to manage weeds in organic Vidalia® sweet onion (Allium cepa) production. If the initial cultivation is delayed, emerged weeds are not controlled. In these cases, herbicides derived from natural products could be used to control the emerged weeds before the initial cultivation. Clove oil has been evaluated for this use, but cool-season weed control is inconsistent during the winter season when Vidalia® sweet onion are grown. Pelargonic acid is a herbicide that can be derived from natural sources or synthesized. Field trials were conducted from 2011 through 2013 to determine the efficacy of pelargonic acid for cool-season weed control in organic Vidalia® sweet onion. All possible combinations of four herbicides and three cultivation regimes using a tine weeder were evaluated. Herbicides evaluated were pelargonic acid (3% and 5% by vol.), clove oil [10% by vol. (2011 and 2012)], d-limonene [14% (2013 only)], and a nontreated control. Cultivation regimes were twice (2×) and four times (4×) at 2-week intervals, and a noncultivated control. Main effects of cultivation and herbicides were independent for all parameters, with no improvement when used in combination. Cultivation 2× and 4× controlled cool-season weeds and improved onion yields, which is consistent with previous research. Pelargonic acid (5%) controlled weeds similar to clove oil (2011 and 2012) and d-limonene (2013), with cool-season weed control efficacy being inconsistent among all herbicides. Onion yield response to weed control from any of the herbicides, including pelargonic acid, also was inconsistent. In organic onion production, inconsistent cool-season performance using pelargonic acid is similar to other herbicides derived from natural sources.

Cool-Season Weed Control Using Ammonium Nonanoate and Cultivation in Organic Vidalia® Sweet Onion Production

2017 ◽  
Vol 32 (1) ◽  
pp. 90-94
Author(s):  
W. Carroll Johnson ◽  
Xuelin Luo
Keyword(s):  
Weed Control ◽  
Cropping Systems ◽  
Clove Oil ◽  
Cool Season ◽  
Control Cool ◽  
Evening Primrose ◽  
Statistical Interactions ◽  
Degree Of Control ◽  
Certified Organic ◽  
Main Effects

AbstractAmmonium nonanoate is registered for weed control in certified organic cropping systems and may be useful to control cool-season weeds in organic Vidalia® sweet onion production. Ammonium nonanoate combined with tine-weeder cultivation was evaluated for weed control in organic onion in Georgia. There were no statistical interactions between main effects of herbicides and cultivation with a tine weeder for cool-season weed control and onion yield, indicating that ammonium nonanoate does not improve weed control compared with cultivation. Ammonium nonanoate at 4% and 6% did not adequately control weeds and onion yields were reduced. Ammonium nonanoate at 8% and 10% controlled cutleaf evening-primrose and lesser swinecress equal to the standard of d-limonene (14%), but the degree of control did not consistently protect onion yields from losses due to weeds. These results are in agreement with previous studies using clove oil and pelargonic acid. There is no advantage to using ammonium nonanoate for cool-season weed control in organic Vidalia® sweet onion production.

Combinations of Corn Gluten Meal, Clove Oil, and Sweep Cultivation are Ineffective for Weed Control in Organic Peanut Production

2013 ◽  
Vol 27 (2) ◽  
pp. 417-421 ◽  
Author(s):  
W. Carroll Johnson ◽  
Mark A. Boudreau ◽  
Jerry W. Davis
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Trials ◽  
Control Treatment ◽  
Clove Oil ◽  
Corn Gluten Meal ◽  
Corn Gluten ◽  
Annual Grasses ◽  
Peanut Production ◽  
Poor Efficacy

Weed control in organic peanut is difficult and lack of residual weed control complicates weed management efforts. Weed management systems using corn gluten meal in combination with clove oil and sweep cultivation were evaluated in a series of irrigated field trials. Corn gluten meal applied in a 30 cm band over the row at PRE, sequentially at PRE+2 wk after emergence, and PRE+2wk+4wk did not adequately control annual grasses and smallflower morningglory. Similarly, a banded application of clove oil applied POST did not adequately control weeds. The only treatment that improved overall weed control was sweep cultivation. Peanut yields were not measured in 2006 due to heavy baseline weed densities and overall poor weed control. Peanut yields were measured in 2007 and were not affected by any weed control treatment due to poor efficacy. While sweep cultivation improved weed control, weeds were controlled only in the row middles and surviving weeds in-row reduced peanut yield. Even when used in combination with sweep cultivation, corn gluten meal and clove oil were ineffective and offer little potential in a weed management system for organic peanut production.

Cultivation and Reduced-Rate Herbicides Weed Control in Sugarbeet Grown for Biofuel

2018 ◽  
Vol 32 (6) ◽  
pp. 726-732
Author(s):  
W. Carroll Johnson ◽  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
Xuelin Luo
Keyword(s):  
United States ◽  
Weed Control ◽  
Southeastern United States ◽  
Integrated System ◽  
Cool Season ◽  
Evening Primrose ◽  
Limited Role ◽  
Reduced Rate ◽  
Main Effects ◽  
Sugarbeet Yields

AbstractSugarbeet, grown for biofuel, is being considered as an alternate cool-season crop in the southeastern United States. Previous research identified ethofumesate PRE and phenmedipham + desmedipham POST as herbicides that controlled troublesome cool-season weeds in the region, specifically cutleaf evening-primrose. Research trials were conducted from 2014 through 2016 to evaluate an integrated system of sweep cultivation and reduced rates of ethofumesate PRE and/or phenmedipham+desmedipham POST for weed control in sugarbeet grown for biofuel. There were no interactions between the main effects of cultivation and herbicides for control of cutleaf evening-primrose and other cool-season species in two out of three years. Cultivation improved control of cool-season weeds, but the effect was largely independent of control provided by herbicides. Of the herbicide combinations evaluated, the best overall cool-season weed control was from systems that included either a 1/2X or 1X rate of phenmedipham+desmedipham POST. Either rate of ethofumesate PRE was less effective than phenmedipham+desmedipham POST. Despite improved cool-season weed control, sugarbeet yield was not affected by cultivation each year of the study. Sugarbeet yields were greater when treated with any herbicide combination that included either a 1/2X or 1X rate of phenmedipham+desmedipham POST compared with either rate of ethofumesate PRE alone or the nontreated control. These results indicate that cultivation has a very limited role in sugarbeet grown for biofuel. The premise of effective weed control based on an integration of cultivation and reduced herbicide rates does not appear to be viable for sugarbeet grown for biofuel.

Efficacy and Crop Response to Glufosinate-Based Weed Management in PAT-Transformed Sweet Corn (Zea mays)

1999 ◽  
Vol 13 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Lee R. Van Wychen ◽  
R. Gordon Harvey ◽  
Mark J. Vangessel ◽  
Thomas L. Rabaey ◽  
David J. Bach
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sweet Corn ◽  
Field Studies ◽  
Yield Response ◽  
Crop Response ◽  
Control Efficacy ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Proso Millet

Field studies were conducted at Arlington, WI, in 1996 and 1997 and at Georgetown, DE, and LeSueur, MN, in 1997 to determine weed control efficacy, crop injury, and yield response of PAT-transformed sweet corn to glufosinate-based weed management. Sequential applications of glufosinate 10 to 18 d apart at 0.4 and 0.3 kg ai/ha controlled common lambsquarters, common ragweed, velvetleaf, wild-proso millet, and fall panicum 90% or better at all locations. Weed control varied little among 0.3, 0.4, or 0.3 and 0.3 (sequential) kg/ha glufosinate rates. Glufosinate applied alone, with, or following atrazine controlled velvetleaf 90% or greater but was less consistent on common ragweed and common lambsquarters (73 to 100%). Atrazine plus metolachlor applied preemergence (PRE) and glufosinate applied alone postemergence (POST) provided inconsistent wild-proso millet and fall panicum control (43 to 99%). Metolachlor followed by glufosinate improved consistency of grass control (> 76%). Glufosinate followed by cultivation provided 80% or greater control of velvetleaf and wild-proso millet. Glufosinate did not injure or delay maturity of PAT-transformed sweet corn. Sweet corn treated with glufosinate resulted in yields greater than or equal to the sweet corn that was hand-weeded or received a standard herbicide treatment.

Co-application of glyphosate plus an insecticide or fungicide in glyphosate-resistant soybean

2012 ◽  
Vol 92 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Nader Soltani ◽  
Christy Shropshire ◽  
Peter H. Sikkema
Keyword(s):  
Adverse Effect ◽  
Weed Control ◽  
Environmental Conditions ◽  
Dry Weight ◽  
Field Trials ◽  
Control Efficacy ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Crop Injury ◽  
Green Foxtail

Soltani, N., Shropshire, C. and Sikkema, P. H. 2012. Co-application of glyphosate plus an insecticide or fungicide in glyphosate-resistant soybean. Can. J. Plant Sci. 92: 297–302. Six field trials were conducted from 2008 to 2010 in Ontario to evaluate soybean injury and weed control efficacy with glyphosate tankmixed with various insecticides or fungicides. There was minimal visual injury (less than 4%) in glyphosate-resistant soybean and no adverse effect on soybean height and yield when cyhalothrin-lambda (Matador®), dimethoate (Lagon®), imidacloprid/deltamethrin (Concept®), spirotetramat (Movento®), pyraclostrobin (Headline®), azoxystrobin (Quadris®), propiconazole (Tilt®), azoxystrobin/propiconazole (Quilt®), tebuconazole (Folicur®) and trifloxystrobin/propiconazole (Stratego®) were tankmixed with glyphosate. Velvetleaf, pigweed species, common ragweed, common lambsquarters and green foxtail control ranged from 91–97, 94–99, 92–99, 80–94 and 98–100%, respectively. However, there was no adverse effect on velvetleaf, pigweed, common ragweed, common lambsquarters and green foxtail control, density and dry weight when one of the insecticides or fungicides evaluated was tankmixed with glyphosate. Based on these results, glyphosate tankmixed with cyhalothrin-lambda, dimethoate, imidacloprid/deltamethrin, spirotetramat, pyraclostrobin, azoxystrobin, propiconazole, azoxystrobin/propiconazole, tebuconazole or trifloxystrobin/propiconazole causes minimal crop injury and has no adverse effect on weed control in glyphosate-resistant soybean under Ontario environmental conditions.

scholarly journals Enhancing the weed control efficacy of two pre-emergence herbicides in maize/jack bean and maize/groundnut intercrops in derived savanna

2021 ◽  
Vol 66 (4) ◽  
pp. 335-350
Author(s):  
Enor Eni ◽  
Olusegun Adeyemi ◽  
Segun Lagoke ◽  
Osebekwin Asiribo
Keyword(s):  
Weed Control ◽  
Block Design ◽  
Field Trials ◽  
Control Methods ◽  
Control Efficacy ◽  
Maize Production ◽  
Cropping Patterns ◽  
Jack Bean ◽  
Derived Savanna ◽  
Cropping Seasons

The inability of pre-emergence herbicides alone to give season-long weed control in maize production justifies the need for supplementary weed control. Field trials were conducted to evaluate intercropped groundnut and jack bean for enhanced weed control efficacy of two pre-emergence herbicides in maize production in 2013/2014 and 2015 cropping seasons at the Federal University of Agriculture, Abeokuta, Nigeria. The experiment was arranged in split-plot fitted in a randomized complete block design with three replications. Main plots consisted of eight weed control treatments of a commercially formulated mixture of prometryne + metolachlor (ProbabenR); prometryne + acetochlor (Super UnionR) each at 2.4 kg a.i ha-1, 1.6 kg a.i ha-1 with and without supplementary hoe-weeding, two hoe-weedings and a weedy check. Sub-plot treatments consisted of eight cropping patterns (sole maize, maize-jack bean and maize-groundnut intercrops, each at two spacings [100 x 37.5 cm and 75 x 50 cm] and sole crops of jack bean and groundnut). All the weed control methods significantly reduced (p<0.05) weed dry matter compared to the weedy check by 10-81%. Maize grain yields (1.4-5.2 t ha-1) were similar for all plots with the weed control methods, except in the 2015 late season, but significantly depressed (21-48%) on those weed-infested throughout. Intercropped jack bean and groundnut with maize significantly suppressed weed growth relative to sole crops of maize, jack bean or groundnut by 20-67%. Therefore, the efficacy of pre-emergence herbicides in this study was enhanced by intercropping of maize with jack bean and groundnut at the spacings of 75 x 50 cm and 100 x 37.5 cm in the early seasons.

Managing Cool-Season Weeds in Sugarbeet Grown for Biofuel in the Southeastern United States

2018 ◽  
Vol 32 (4) ◽  
pp. 385-391 ◽  
Author(s):  
W. Carroll Johnson ◽  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
Xuelin Luo
Keyword(s):  
United States ◽  
Weed Control ◽  
Coastal Plain ◽  
Southeastern United States ◽  
Temperature Limit ◽  
Field Trials ◽  
Maximum Temperature ◽  
Severely Injured ◽  
Wild Radish ◽  
Cool Season

AbstractSugarbeet, grown for biofuel, is being considered as an alternate cool-season crop in the southeastern U.S. coastal plain. Typically, the crop would be seeded in the autumn, then grow through the winter and be harvested the following spring. Labels for herbicides registered for use on sugarbeet grown in the traditional sugarbeet production regions do not list any of the cool-season weeds common in the southeastern United States. Field trials were initiated near Ty Ty, GA, to evaluate all possible combinations of ethofumesate applied PRE, phenmedipham+desmedipham applied POST, clopyralid POST, and triflusulfuron POST for cool-season weed control in sugarbeet. Phenmedipham+desmedipham alone and in combination with clopyralid and/or triflusulfuron effectively controlled cutleaf eveningprimrose, lesser swinecress, henbit, and corn spurry when applied to seedling weeds. Ethofumesate PRE alone was not as effective in controlling cool-season weeds compared to treatments containing phenmedipham+desmedipham POST. However, ethofumesate PRE applied sequentially with phenmedipham+desmedipham POST improved weed control consistency. Clopyralid and/or triflusulfuron alone did not adequately control cutleaf eveningprimrose. Triflusulfuron alone effectively controlled wild radish. In the 2013–2014 and 2014–2015 seasons, December-applied POST herbicides did not injure sugarbeet. However, in the 2015–2016 season POST herbicides were applied in late October. On the day of treatment, the maximum temperature was 25.4 C, which exceeded the established upper temperature limit of 22 C for safe application of phenmedipham+desmedipham, and sugarbeet plants were severely injured. In the southeastern United States, temperatures frequently exceed 22 C in early autumn, which may limit phenmedipham+desmedipham use for controlling troublesome cool-season weeds of sugarbeet in the region. Weed control options need to be expanded to compensate for this limitation.

Interactions among Cultivation, Weeds, and a Biofungicide in Organic Vidalia® Sweet Onion

2017 ◽  
Vol 31 (6) ◽  
pp. 890-896
Author(s):  
W. Carroll Johnson ◽  
Bhabesh Dutta ◽  
F. Hunt Sanders ◽  
Xuelin Luo
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Interactive Effects ◽  
Yield Response ◽  
Evening Primrose ◽  
Bacterial Diseases ◽  
Hand Weeding ◽  
Giant Knotweed ◽  
Main Effects ◽  
Weed Removal

Weed management in the organic Vidalia® sweet onion production system is largely dependent on multiple cultivations with a tine weeder. Earlier research suggested cultivation with a tine weeder did not predispose onion bulbs to infection during storage. Trials were conducted from 2012 through 2014 near Lyons, GA, to determine the interactive effects of cultivation, weed removal, and a biofungicide on weed densities, onion yield, grade, and diseases of stored onion. Cultivation twice or four times at biweekly intervals with a tine weeder reduced densities of cutleaf evening-primrose, lesser swinecress, and henbit compared with the noncultivated control, although weeds surviving cultivation were very large and mature at harvest. Cultivation generally improved onion yields over the noncultivated control, except in 2014, when baseline weed densities were high and weeds surviving cultivation were numerous. Weeds removed by hand weeding improved onion yields, but that effect was independent of cultivation. Four applications of a biofungicide derived from giant knotweed had no effect on onion yield. Cultivation had no effect on incidence of the fungal disease botrytis neck rot, with inconsistent effects on the bacterial diseases center rot and sour skin. Weed removal with hand weeding did not affect diseases of stored onion. The biofungicide had no effect on diseases of stored onion. These results demonstrate the limitations of cultivation when cool-season weed infestations are dense. With no interactions among main effects, weed control and onion yield response to cultivation and hand weeding are independent. Cultivation for weed control is much less costly than hand weeding. With no interaction between the cultivation and weed removal main effects, it is not necessary to supplement tine weeder cultivation with costly hand weeding.

The Potential Use of Vinegar and a Clove Oil Herbicide for Weed Control in Sweet Corn, Potato, and Onion

2009 ◽  
Vol 23 (1) ◽  
pp. 120-128 ◽  
Author(s):  
G. J. Evans ◽  
R. R. Bellinder
Keyword(s):  
Weed Control ◽  
Sweet Corn ◽  
Field Trials ◽  
Clove Oil ◽  
Weed Species ◽  
Marketable Yield ◽  
Yield Data ◽  
Application Timing ◽  
Time Of Application ◽  
Potential Use

Natural products might provide an organic means of weed control. Our objective was to evaluate the potential use of vinegar and a clove-oil product with regard to how volume, concentration, and application timing affect weed control and crop response. Treatments included broadcast applications of 200- and 300-grain vinegar at 318 liters per hectare (L/ha), 150- and 200-grain vinegar at 636 L/ha, a 3.4% v/v clove oil mixture in water (318 L/ha), and a 1.7% clove oil mixture in 200-grain vinegar (318 L/ha). Field trials were conducted in sweet corn, onion, and potato. Weed control, weed biomass, crop injury, and yield data were collected. Corn treated at 15 and at 30 to 45 cm was initially burned and stunted by these products. By 4 wk after application much of the initial injury was outgrown. Late applications significantly reduced yields of early-maturing sweet corn ‘Trinity’. With the exception of the 200-grain vinegar (318 L/ha) treatment, early applications to sweet corn ‘Avalon’ did not reduce marketable yield. Two hundred-grain vinegar (636 L/ha) applied to pre-emergence–flag stage onion reduced the duration of the first handweeding by 59 to 67%. All treatments reduced onion yields when treated at the 2-leaf stage. Potato treated early (2 to 10 cm) and late (30 cm) were injured by all vinegar treatments 59 to 83%, 1 d after treatment (DAT). Potato yield losses were insignificant with applications of 3.4% clove oil and with some low-volume (318 L/ha) vinegar treatments. Product efficacy was dependent on the weed species and their size at the time of application. Weed control was greatest (83%, 1 DAT) with 200-grain vinegar (636 L/ha). Broadcast applications of vinegar and clove oil have potential for use on young, actively growing sweet corn, onion, and potato.

Interaction of Glyphosate and Pelargonic Acid in Ready-to-Use Weed Control Products

2009 ◽  
Vol 23 (4) ◽  
pp. 544-549 ◽  
Author(s):  
Glenn Wehtje ◽  
James E. Altland ◽  
Charles H. Gilliam
Keyword(s):  
Weed Control ◽  
Pelargonic Acid ◽  
Control Efficacy ◽  
Yellow Nutsedge ◽  
Greenhouse Experiments ◽  
Equal Rate ◽  
Early Injury ◽  
And Control ◽  
Large Crabgrass

Glyphosate-based, ready-to-use weed control products often contain pelargonic acid (PA) at a concentration equivalent to that of the glyphosate. It remains unclear what benefit, if any, this combination provides. Greenhouse experiments using large crabgrass, yellow nutsedge, longstalked phyllanthus, and prostrate spurge were conducted to determine whether the addition of PA improved weed control efficacy compared to glyphosate alone. Glyphosate was applied at a series of rates, ranging from 0.11 to 1.12 kg ae/ha, either alone or with an equal rate of PA. Addition of PA to glyphosate was synergistic only in longstalked phyllanthus and yellow nutsedge, and this synergism was manifested only as an increase in the amount of early (i.e., 5 to 7 d after treatment) visual injury. Conversely, longer-term control and control of regrowth was either not affected or reduced by the addition of PA. We conclude that the addition of PA to glyphosate in ready-to-use weed control products is neither warranted nor justified. However, we also note that the increase in early injury that was observed in only two of the four species evaluated could be an important attribute for the consumers for which these products are targeted.

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