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ARS Home » Southeast Area » Houma, Louisiana » Sugarcane Research » Research » Publications at this Location » Publication #313489
Title: Going natural: Effective weed control in squash with pelargonic acid

Author
item Webber Iii, Charles
item TAYLOR, MERRITT - Oklahoma State University
item SHREFLER, JAMES - Oklahoma State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2015
Publication Date: 10/1/2015
Citation: Webber III, C.L., Taylor, M.J., Shrefler, J.W. 2015. Going natural: Effective weed control in squash with pelargonic acid [abstract]. Southern Association of Agricultural Scientists Annual Meeting, January 30 - February 4, 2015, Atlanta, Georgia. S53.

Interpretive Summary:

Technical Abstract: Pelargonic acid, a natural, but not certified organic herbicide, has been shown to be phytotoxic, acting as a contact herbicide, injuring and killing plants through cell membrane disruption. Pelargonic acid, a fatty acid also known as nonanoic acid, is a nine-carbon chained organic compound found in many plants, animals, and foods. Two years of field research in southeast Oklahoma determined that pelargonic acid was an effective weed control method for smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.], cutleaf groundcherry (Physalis angulata L.), and spiny amaranth (Amaranthus spinosus L.) in squash (Cucurbita pepo L.). Pelargonic acid [Scythe® (57% pelargonic acid)] was post-directed applied at three rates (3, 6, and 9% v/v Scythe®) in sequential applications 8 days apart. Ninety-eight percent of smooth crabgrass and 94% of broadleaf weeds were controlled with the 9% Scythe® rate after the sequential application. The 9% rate of Scythe® was less effective in controlling yellow nutsedge (Cyperus esculentus L.), with only 41% control 1 day after the sequential application. Unfortunately, increasing the rate of Scythe® also increased the crop injury, resulting in 4.4, 8.0, and 12.5% injury for Scythe® at the 3, 6, and 9% rates, respectively. As the result of crop injury, the 6% Scythe® treatment produced the highest squash yields (kg/ha) and fruit number (fruit/ha). The 6% Scythe® applied in a timely sequential application has the potential to provide adequate weed control with minimal crop injury that results in yields equivalent to weed free conditions.