Influence of soil substrate on the biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot on bean (Phaseolus vulgaris)

Abstract: Biocontrol control effect of Pseudomonas CMR12a, a rhizospheric bacteria which isable to produce phenazines and biosurfactants, was investigated in different soil-sandcombinations. According to statistics, disease suppressive capacity of phenazines andbiosurfactants was substrate-dependent and disease severity increased with the proportion ofsand. In substrate containing 50% or 75% of potting soil, the presence of either phenazines orbiosurfactants was sufficient to suppress bean root rot. However, in substrate containing 25% ofpotting soil, the involvement of both compounds was required to achieve successful biocontrolactivities.