Abstract

Indian neem oil, petroleum ether extract (laboratory neem oil), ethanol and methanol extracts of neem seed kernels at 250 ppm - 4000 ppm concentrations were investigated us antifungal agents on the phytopathogenic fungus Fusarium oxysporum. All treatments exhibit the antifungal activity on phytopathogenic fungus Fusarium oxysporum with different activities depending on the type of treatment materials and concentrations. The highest antifungal activity is at 4000 ppm concentration. The ICso values showed that the ethanol extract has the highest antifungal activity on the growth of the fungus Fusarium oxysporum. Besides, the purified azadirachtin at 4000 ppm was also used for investigating the antifungal activity on fungus Fusarium oxysporum and purified azadirachtin exhibited a very little inhibition on the radial growth of this fungus. It probably showed that the antifungal activity of neem seed kernel extracts are the synergistic effect of many compounds other than azadirachtin.