Bioactivity of Ethanolic Extracts of Dipteryx punctata on Colletotrichum musae

Abstract

Bioactivity with antifungal properties has already been reported for some species of the genus Dipteryx. However, little is known about Dipteryx punctata. We evaluated the antifungal activity, in vitro and in vivo, of extracts of leaves, branches and fruits of D. punctata on Colletotrichum musae, the causal agent of anthracnose in bananas. The extracts and the coumarin standard were tested in vitro, at concentrations of 10%, 20%, 30%, 40%, and 50% (w/v), added in potato-dextrose-agar (PDA) medium. The experimental design was completely randomized, factorial design, with four replications. The average diameter of the fungal colonies was evaluated daily for eight days, and at the end, the percentage of inhibition and growth rates were calculated. For in vivo tests, the products were tested at concentrations of 40% and 50%, in preventive and curative applications. In these tests, three medium disks (5 mm) containing phytopathogen structures were deposited at opposite points of the fruits, and remained in a humid chamber for 48 h. Anthracnose lesions were measured at an interval of two days, up to eight days after fungus inoculation. In the in vitro essay, the extracts of the branches and residues of the fruits of D. punctata and the coumarin pattern caused the biggest reductions in the average diameter of the colonies of the phytopathogen. D. punctata and coumarin extracts were promising in terms of in vivo antifungal activity, especially in preventive applications, being an important source of investigation for the formulation of natural products as sustainable phytosanitary measures.