Effect of fatty acid salts on the growth of Botrytis cinerea

Abstract

The toxicity of a range of potassium salts of fatty acids was bioassayed against Botrytis cinerea Pers. in agar culture. Growth inhibition increased with number of carbon atoms of the short chain fatty acid salts, reached a peak around C10 (caprate), and then declined. Salts of dicarboxylic acids were nontoxic at the highest levels tested, while the unsaturated C11:1, undecylenate, was as potent as caprate. Caprate at 0.1% inhibited growth of most B. cinerea isolates tested and prevented the remaining isolates from forming sclerotia. Conidial germination of all isolates was prevented by 0.05% caprate. Discrepancies in the literature regarding control of B. cinerea with soft soaps are suggested to be due to varying fatty acid composition of the soaps used.