Use of medicinal plant extracts and chitosan as an alternative to chemicals to control mango postharvest anthracnose

Abstract

Anthracnose caused by Colletotrichum gloeosporioides is one of the most important post-harvest diseases affecting mangoes’ post-harvest management, resulting in huge post-harvest losses. However, the present research aims to study the antifungal activity of chitosan and aqueous extracts of Tectona grandis L. and Artemisia annua L. leaves on the development of C. gloeosporioides. In the “in vitro” evaluation, chitosan at the concentration of 2.5% (v/v) and the two extracts evaluated at 10% (w/v) showed a fungicidal effect on C. gloeosporioides. While for the evaluation of mango fruit (“in situ”), the anthracnose disease was controlled with 2.5% (v/v) chitosan and 10% (w/v) aqueous extracts applied after inoculation of C. gloeosporioides. The chitosan and aqueous extract treatments did not affect the acidity and pH of the mango. However, all products used on mango fruit reduced mass loss and delayed the decline in firmness, skin greenness and ascorbic acid content after ripening. They also showed a beneficial effect on total soluble solids content. A concentration of 2.5% chitosan and 10% aqueous extracts effectively inhibited anthracnose disease and improved some ripening parameters of mangoes. Therefore, Chitosan and aqueous extracts of A. annua and Teak (Tectona grandis L.) leaves can be used as an alternative to synthetic chemicals to substantially reduce postharvest mango anthracnose.