Bioefficacy of Organic Acids against Colletotrichum gloeosporioides (Penz.) Penz. and Sacc., Causal Organism of Mango (Mangifera indica L. cv. “Carabao”) Anthracnose

Abstract

Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. is considered as the most serious and the most important field and postharvest disease of mango fruits. In this study, the bioefficacy of some organic acids against the pathogen isolated from mango is reported. Formic acid, acetic acid, benzoic acid (BA), salicylic acid (SA), p-hydroxybenzoic acid (p-HBA), and m-hydroxybenzoic acid (m-HBA)showed activity against C. gloeosporioides. The minimum inhibitory concentration (MIC) of the organic acids was 40 mM for acetic acid and formic acid, and 70 mM for BA, SA, m-HBA, and p-HBA. The minimum fungicidal concentration (MFC) was found to be the same as the MIC. The acids showed a significant inhibitory effect on conidial germination over the 72-h incubation period. Azoxystrobin (Amistar®), at its recommended dosage, delayed the onset of germination but its effect eventually diminished after 24 h. The results of this study indicate that organic acids can be used as an alternative control strategy for mango anthracnose and these acids were more effective than Amistar® when applied at the MIC. These organic acids are also safer and generally regarded as safe (GRAS) compounds.