Evaluation of Bioagents for their Compatibility in the Development of Consortium for Enhanced Efficacy

The concept of development of microbial consortia for bio-control relies on the fact that bioagents under natural habitats live in communities with some benefits for plants. Application of bioagents in a consortium may improve efficacy, reliability and consistency of the bioagents even under diverse soil and environmental conditions. Diversity in biocontrol mechanisms offered by each bioagent in consortium may help in enhancing disease suppressiveness and may also strengthen the capabilities of the partners in an additive or synergistic manner. Till now no guideline has been published for the evaluation of bioagents to test their compatibility before developing bioagent consortium. In the present studies compatibility among biocontrol potential Trichoderma-Pseudomonas and Trichoderma-Trichoderma isolates was studied by dual culture, mixed formulations and using cell free cultures. In dual culture all the combinations (14 no.) were found compatible with each other as no isolate inhibited the growth of one-another i.e. absence of  inhibition zone. All the mixed formulations of potential Trichoderma-Pseudomonas isolates (8 no.) were found compatible with each other as they were growing simultaneously on PDA without antagonizing the growth of other or formation of inhibition zone in their combinations. The cell free cultures of each Trichoderma and Pseudomonas isolates tested with each other using Food Poison Technique showed synergistic effects on their fresh mycelial weight among some combinations while majority showed no significant differences with their checks. Further all the combinations (14 no.) were tested for their effects on seed germination and vigour index of chickpea in glasshouse. All the combinations showed significantly better seed germination while some combinations viz. Th14+Psf173, TCMS36+Psf173,Th17+Th19,Th17+Psf2,Th17+TCMS36 and Th14+Psf2 showed better plant vigour index (43.5 to 44.9% ) as compared to their checks (28.8 to 41.5%).These guidelines