Bioefficacy of Bacillus subtilis isolates against Fusarium solani, the causal agent of wilt of chilli

Biological control is an important strategy to reduce the use of chemicals in disease management. Recently, a considerable attention has been given to the plant growth rhizobacteria which positive influence on plant growth and health. Among the PGPR microbes, Bacillus subtilis play a major role in plant growth promotion and biocontrol. Thirty isolates of B. subtilis were obtained from different rhizosphere soil samples from different parts of North Eastern Karnataka region. All the isolates were rod shaped, positive for gram reaction, endospore, oxidase, catalase, starch hydrolysis, negative for indole, KOH test and green coloured colonies were grown on Hichrome Bacillus agar medium. All the isolates showed varied levels of biocontrol and PGPR activities in vitro against Fusarium solani is the causal agent of wilt disease in chilli. Thirty isolates of B. subtilis were recorded the varied levels of inhibition of mycelial growth of F. solani. Among different isolates, BS16 showed maximum inhibition of 65.27 per cent which differed significantly from others followed by BS 30 with 63.42 and least in case of BS17 isolate (38.88 %) compared to check isolate which showed 41.94 per cent inhibition of mycelial growth of F. solani. B. Subtilis BS16 is one the potential bioagent which can be used in chilli ecosystem for integrated disease management.