OPTIMIZATION AND EVALUATION OF MICROBE FORTIFIED COMPOSTS AS BIOCONTROL AGENTS AGAINST PHYTOPATHOGENIC FUNGI

Abstract

A set of bacterial (B1-10) and cyanobacterial strains (C1-C14) were evaluated for their fungicidal activity against selected phytopathogenic fungi - Fusarium solani, Fusarium oxysporum, Fusarium oxysporum lycopersici, Fusarium moniliforme, Pythium debaryanum and Rhizoctonia solani. Further, they were used to amend rice straw compost and the filtrates were evaluated against the selected fungi after 10 and 20 days of incubation. Six promising strains, including three bacterial and three cyanobacterial strains were selected and characterised in terms of activity of hydrolytic enzymes. Interestingly, C12 strain (Anabaena spp.) showed highest activity of cellulase, chitosanase and β 1, 3 glucanase. These strains were then evaluated by optimization of inoculum levels (1-5%) in the rice straw compost. The strains B3, B5, C8 and C12 were observed to be most promising as they exhibited inhibition and significantly higher activity of microbiological parameters and hydrolytic enzymes at 1-2% level of inoculum in the compost. Further investigations are being undertaken to scale up the development of compost based biocontrol agents using these strains for evaluation at field level.