ISOLATION, CHARACTERIZATION AND SCREENING OF BACILLUS SPP. FOR PLANT GROWTH PROMOTING ATTRIBUTES AND ANTAGONISTIC ACTIVITY AGAINST RHIZOCTONIA SOLANI, SCLEROTIUM ROLFSII AND COMPATIBILITY WITH COMMONLY USED PESTICIDESJ. SAI PRASAD$, R. SUBHASH REDDY$, P. NARAYAN REDDY AND P. HARIKRISHNA$Abstract Twenty four (24) isolates of plant growth promoting rhizobacteria from rhizospheric soils of Rajendranagar were isolated and identified. They were screened in vitro for PGPR properties like phosphate solubilization, siderophore, IAA, HCN productions, Antagonistic activity against Rhizoctonia solani, Sclerotium rolfsii and compatibility with commonly used pesticide molecules. The results revealed that 50% of the Bacillus isolates showed positive results for phosphate solubilization, 100% for ammonia, 91.6% for IAA, 70.83% for siderophores and 58.33% isolates showed for HCN productions. Out of 24 Bacillus isolates 4 isolates CRuB2, SBpB2, ABuB1 and ARpB2 showed inhibition potential against both Rhizoctonia solani and Sclerotium rolfsii. The maximum per cent inhibition against Rhizoctonia solani was showed by CRuB2 (37.15%) and ABpB2 (37.15%). The maximum per cent inhibition against Sclerotium rolfsii was showed by CRuB2 (37.15%), SBpB2 (37.15%). The isolate that showed maximum inhibition potential against Rhizoctonia solani was also inhibitory to Sclerotium rolfsii to a lesser extent based on per cent inhibition and vice versa. Hence it can be inferred that the Bacillus isolates CRuB1, CRpB2, SBuB1, SBpB1, SRuB1, SRuB2, ARuB2 and ARpB1 could be considered for their bio control activity. Among the pesticides tested Azoxystrobin (fungicide), Flubendiamide (insecticide) and Propaquizafop (herbicide) were found to inhibit Bacillus at recommended / half recommended dosage. However other fungicides, insecticides and herbicides were compatible with all the isolates tested. Out of the 24 isolates tested for their compatibility with the four each of the fungicides, insecticides, herbicides and based on their PGPR attributes and antagonistic activity, the isolate of Bacillus isolate SBpB2 showed potential as PGPR
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