Volume 8, Issue 5 (May 2011)
Novel Formulations of an Organic Acid Herbicide
Herbicides sold commercially to producers of organic crops have low specific activity. The potential exists to increase the herbicidal activity of the more active candidate herbicides with appropriate and acceptable adjuvants and emulsifiers. The naturally occurring organic acid chosen for this study was caprylic acid (C8). Caprylic disrupts the integrity of the plasmalemma of plant cells, causing desiccation. Both the spread and penetration of a spray solution become important in maximizing herbicidal or desiccant activity. The addition of an emulsification system is necessary to facilitate microemulsion stability when formulations are diluted in water. In greenhouse studies, a natural emulsifier from naturally occurring sources was found to be as effective as a phosphate ester emulsifier for enhancing caprylic acid activity on velvetleaf (Abutilon theophrasti), giant foxtail (Setaria faberi), and common lambsquarters (Chenopodium album). Citric acid, when used as an adjuvant in C8 product formulations, increased herbicidal activity on the weed species tested. Desiccation obtained with organic herbicide formulations were observed to be much greater than that obtained with a currently available herbicide formulation such as MATRAN.