MANAGEMENT OF DAMPING OFF DISEASE BY EXTRACTS OF ALBIZIA LEBBECK (L.) BENTH

Antifungal potential of various parts of Albizia lebbeck (L.) Benth. was evaluated against the destructive damping off disease causing fungus Rizoctonia solani Kuhn. Different concentrations of leaf, fruit, bark and root methanol extracts viz., 1, 2, 3, 4 and 5% were tested against R. solani. Leaf extract was found more effective than fruit, bark and root extracts. The methanolic leaf extract of A. lebbeck was fractioned between n-hexane, chloroform, ethyl acetate and n-butanol. The bioactivities of these isolated fractions were tested against R. solani. The chloroform fraction was significantly inhibited the test fungus growth. So, this chloroform fraction was further analyzed to separate various constituents through column chromatography. Eleven sub-fractions were isolated from column chromatography of chloroform extract and their minimum inhibitory concentration ( MIC) was evaluated against R. solani. Synthetic fungicide ( Metalaxyl + mancozeb, 72 WP) was used as reference fungicide. After 72 hrs incubation period fraction (7) and the fungicide were effectively suppressed the spore germination of R. solani with MIC of 0.00019 mg/ml. The present study can be concluded that A. lebbeck possesses active antifungal constituents against R. solani.