Combining pseudomonas and Trichoderma strains with organic amendments to enhance suppression of root rot disease incidence in coleus

The fungal and bacterial biocontrol agents and organic amendments were tested individually and in combinations for their efficacy against root rot pathogen, Macrophomina phaseolina under invitro, glass house and field conditions. Among the fungal and bacterial (Pseudomonas) antagonists screened, Trichoderma viride, T. harzianum, Pseudomonas fluorescens (Pf7) isolates exhibited maximum inhibition compared to other isolates. Among the organic amendments, tested invitro against the pathogen, neem cake and coir pith compost were most effective in reducing the growth of the pathogen. The compatibility studies revealed the isolate of T. viride, T. harzianum, P. fluorescens (Pf7) were compatible with each other and also with eight organic amendments. Of the various treatments tested, soil application of T. viride and neem cake recorded least incidence of disease when compared to individual treatments both under glass house and field conditions. Furthermore, the same treatment also increased the yield compared to control.