Abstract

This study was, undertaken to investigate the in vitro anti-fungal activities of ethanol extracts of three medicinal plants (Azadirachta indica, Chromolaena odorata and Zanthoxylum zanthoxyloides) against Macrophomina phaseolina and Lasiodiplodia theobromae isolated from Jatropha curcas. Antifungal bioassays using pour plate method were carried out by using leaf extracts of 10, 20, 30, 40 and 50% concentration in 100 ml of ethanol. In general, all the extracts significantly reduced the mycelia growth of the target fungi species, though there were significant differences (P<0.05) among different concentrations used. Increase in extracts concentration led to reduction in fungal mycelia growth therefore, the highest inhibition for each was at the highest concentration of 50%. C. odorata extracts exhibited the highest antifungal activity for M. phaseolina, while extracts of Z. Zanthoxyloides exhibited the highest antifungal activity for species of L. theobromae (100.00±0.0). This study therefore concludes that the ethanol leaf extracts of medicinal plants contain secondary metabolites with potentials to serve as bio-fungicides in the management of Macrophomina phaseolina and Lasiodiplodia theobromae, pathogens of Jatropha curcas and other forest tree species.

Key Words: Antifungal, Jatropha curcas, Extracts, Secondary metabolites