Determination of antifungal efficiency of some fungicides and secondary metabolites of Trichoderma species against Botrytis cinerea

Abstract

Aim: The present study aimed to investigate the antifungal effects of fenhexamid, cyprodinil+fludioxanil, Bacillus subtilis QST 713, Trichoderma secondary metabolites (EGE-K-38 and EGE-K-71) on 6 isolates of necrotrophic fungi (Botrytis cinerea) under in- vitro conditions. Methodology: A dual culture technique was used to evaluate the effects of volatile compounds produced by Trichoderma in culture media against Botrytis cinerea isolates. For non-volatile and volatile metabolites, measurements for growth inhibition were made with the mixture of filter sterilized liquid medium of Trichoderma and potato dextrose agar. The fungicidal effects of these non-volatile metabolites and fungicides were first evaluated according to the effective concentration (EC50) data of growing mycelium inhibition of disease agents. Results: According to the results obtained, the drug/agent with the lowest fungicidal activity was determined as fenhexamide, which seems to have the lowest EC50 value of 0.05 ug m l-1. Both non-volatile metabolites and volatile metabolites of Trichoderma strains showed strong inhibition against B. cinerea isolates under experimental conditions. The highest growth inhibition percentage was determined with volatile metabolites of Trihoderma atroviride EGE-K-71 strain as 71.8%. Interpretation: The study suggest that filtrates that contain secondary metabolites and volatile compounds of Trichoderma strains produced in both liquid culture and dual culture conditions can be used as an effective fungal control agents against pre and postharvest contamination of grapes with Botrytis cinerea.