IN VITRO CONTROL OF COLLETOTRICHUM GLOEOSPORIOIDES BY USING CHITOSAN LOADED NANOEMULSIONS

Anthracnose is a major devastating disease of many fruits including dragon fruit and vegetables especially in tropical regions of the world. Anthracnose is commonly controlled with synthetic fungicides. However, due to certain harmful effects of synthetic fungicides on human health and environment, there is a need to look for some safe alternatives. In this context, a present study was designed to evaluate a natural product such as chitosan to control anthracnose caused by the fungus Colletotrichum gloeosporioides (Penz.) Penz & Sacc isolated from dragon fruit plants. Chitosan was used in the form of nanoemulsions which is a novel technology. Nanoemulsions of different droplet sizes (200, 400, 600, 800, 1000 nm) were prepared using two types of chitosans (low molecular weight and locally prepared chitosan) at 1.0% concentration and evaluated in vitro to control the growth of conidia, dry weight of mycelia and sporulation of C. gloeosporioides. The results regarding in vitro studies showed that low molecular weight chitosan at 1.0% concentration with 600 nm droplet size showed the best results in terms of inhibiting conidial germination, reducing dry weight of mycelia and sporulation as compared to the locally prepared chitosan and untreated control. The results of the present study suggest that chitosan in the form of nanoemulsions could be used as a biofungicide for controlling anthracnose of dragon fruit plants in the future.