SURVIVAL OF POTENTIAL BIOCONTROL BACTERIA IN VARIOUS FORMULATIONS ANDTHEIR ABILITY TO REDUCE RADISH DAMPING-OFF CAUSED BY RHIZOCTONIA-SOLANI

Efficacy of various carrier/cover powder combinations in sustaining po pulations of Bacillus cereus, B. pumilus and Pseudomonas fluorescens t hat showed inhibitory action against Rhizoctonia damping-off was asses sed. Bacillus cereus increased its population size twentyfold after 15 0 days of storage in peat-based formulation. Bacillus cereus and B. pu milus survived without decreasing its population size for at least 150 days on radish seeds coated with peat- or vermiculite-based formulati ons, stored at room temperature. Although the population size declined after 30 days of storage, P. fluorescens survived on the seeds in all formulations used, even up to 150 days of storage. When the treated s eeds were stored 90 days and then sown in soil, B. cereus and P. fluor escens in peat or vermiculite/clay formulations controlled effectively Rhizoctonia damping-off in greenhouse trials.