Submitted to: Oklahoma Agriculture Experiment Station Departmental Publication
Publication Type: Experiment Station
Publication Acceptance Date: June 10, 2006
Publication Date: June 15, 2006
Citation: Webber III, C.L., Shrefler, J.W. 2006. Vinegar: Application volumes and adjuvants for weed control. 2005 Vegetable Weed Control Studies, Oklahoma State University, Division of Agricultural Sciences and Natural Resources, Department of Horticulture and Landscape Architecture. Stillwater, OK. MP-162, p. 28.
Vinegar has been identified as a potential organic herbicide, yet more information is needed to determine influence of application volume and use of additives (adjuvants) on weed control. Vinegar is a solution containing water and acetic acid, an organic acid produced through the natural fermentation of plant materials containing sugars. Acetic acid acts as a contact herbicide, injuring and killing plants by first destroying the cell membranes, which then causes the rapid desiccation of the plant tissues. Household vinegar typically contains 5% acetic acid. Vinegars with acetic acid concentrations of 11% or greater are available commercially, these products can burn the skin and cause severe eye injury, including blindness. The objective of this research was to determine the effect of application volumes and adjuvants on weed control efficacy using vinegar with a 20% acetic acid concentration. Field research with vinegar was conducted in southeast Oklahoma (Lane, OK) during the 2005 growing season. The factorial experimental design included vinegar at three sprayer application volumes (20, 80, and 160 gpa), three adjuvants (none, orange oil, and non-ionic surfactant), and two weedy-checks. Visual weed cover and control ratings were collected throughout the experiment. The experiment had very high weed densities with multiple species of grass and broadleaf weeds. Vinegar was more effective in controlling broadleafs than in controlling grasses. When averaged across adjuvants (none, orange oil, and non-ionic surfactant) weed control increased as application volumes increased from 20 to 160 gpa. Additional research will integrate the use of vinegar within vegetable production systems.