Effect of neem (<i>Azadirachta indica</i> A. Juss) leaf extract on the growth of <i>Aspergillus species</i> isolated from foliar diseases of rice (<i>Oryzea sativa</i>)

Abstract

Rice blast is probably the most frequent and most destructive rice disease caused by fungi. This study was carried out to determine effect of Neem (Azadirachta indica A. Juss) leaf extract on the growth of Aspergillus niger, Aspergillus flavus, Aspergillus nidulans and Aspergillus fumigatus isolated from foliar diseases of rice. The fungal isolated from foliar part of rice were revealed as Aspergillus spp out of 30 samples collected after a disease field survey. Ethanol and aqueous extracts of Neem leaf were tested against the fungal isolates. The efficacy of the extracts was studied and determined by applying in different concentrations of 5, 10 and 15ml/L. Effect of the extracts was determined by measuring radial growth (mm) of the isolated fungi on potato dextrose agar in petri-dishes. Resulted obtained shown that statistically, the ethanolic extract was more effective than aqueous extract in all cases. However, the effectiveness of the extracts was dependent on the concentration used. The phytochemical analysis of revealed the present of alkaloids, saponins, tannins, phenols, flavonoids, and terpenoids while anthraquinone, phalabatonine and steroids were not detected. Therefore, uses of Azadirachta indica could be recommended to control the foliar diseases (Aspergillus spp) of rice which help to increase the grain yield of that crop.