Rhizobacteria-based bio-formulations for the management of fruit rot infection in chillies

The efficacy of 13 plant growth promoting antagonistic rhizobacterial strains were evaluated against chilli fruit rot and dieback incited by Colletotrichum capsici. Among them Pseudomonas fluorescens (Pf1) and Bacillus subtilis were found to be effective in increasing the seed germination and seedling vigour. The addition of neem extract and chitin increased the antagonists population in culture medium. Both Pf1 and B. subtilis were compatible with each other. In a further study, talc-based formulations of plant growth promoting rhizobacteria either single or mixed along with or without chitin and neem amendments were developed and tested under greenhouse and field conditions. The PGPR mixed bioformulation Pf1 + B. subtilis + neem + chitin was found to be the best for reducing the fruit rot incidence besides increasing the plant growth and yield parameters under both greenhouse and field conditions. There was multifold increase in chitinase, beta-1, 3 glucanase, peroxidase, polyphenol oxidase, phenylalanine ammonia lyase and phenol accumulation in plants treated with mixed formulation. (C) 2004 Elsevier Ltd. All rights reserved.