Antifungal effects of leaf Extracts of three Plant Species against Colletotrichum musae the Causal agent of Anthracnose Postharvest Disease of Banana fruit

Abstract

Anthracnose is a postharvest disease of banana caused by the fungus Colletotrichum musae that results in major economic losses during transportation and storage. For the management of banana anthracnose, antifungal effects of three medicinal plants (Azadirachta indica, Calotropis procera and Anacardium occidentale) were assessed in this study. The extracts of the plants were prepared using water, the phytochemical constituents were determined and agar well diffusion method was used to assess the toxicity of each extract at 50mg/mL100mg/mL and 150mg/mL. The pathogen was isolated from banana infected with anthracnose disease. The results revealed the presence of one or more phytochemicals in each of the plant extracts. Among these were alkaloids, saponnin, tannins, anthocyannin, phenol and flavonoids. All the extracts inhibited mycelia growth of Colletotrichum musae. The inhibition of mycelia growth of the pathogen increased with increase in concentration and days of incubation. At the end of day 5 of incubation, the inhibition at 150mg/mL of all the extracts was significantly different(P<0.05) from other concentrations. However, in all, C. procera extracts gave the highest percentage growth inhibition of the pathogen at all levels of concentrations tested while A. indica extracts though effective was the least but not significantly different from A. occidentale. Therefore, since these plants are cheap, easy to obtain and extract with a simple process of maceration or infusion, more trials on the dosage and formulation on the control of banana anthracnose disease are recommended.