Effect of pesticide amended soil on population of Pseudomonas fluorescens under green house conditions

Pseudomonas fluorescens is an important beneficial microorganism that enhances growth of a crop plant and is used as a bioagent. It is ecofriendly and inhabitant of soil, which play an important role in integrated disease management. Isolates of P. fluorescens were selected on the basis of morphological and biochemical tests. All isolates were Gram negative and rod shaped. They were positive for arginine dihydrolysis, catalase and H2S gas production. Amongst them, four isolates showed their ability to hydrolyze starch, two isolates showed citrate utilization, 13 isolates showed KOH test and 12 isoates showed urease test whereas, four isolates showed oxidase test. Among fifteen isolates, Pf2 gave maximum growth inhibition of Fusarium oxysporum f. sp. ciceri (60.36%) and also of Rhizoctonia bataticola (60.50%). Enumeration of P. fluorescens population was high in the soil where P. fluorescens was added @ 15g/kg in pesticides amended soil. Whereas, P. fluorescens population was increased up to 60 days after incubation and decline at 90 days. All pesticides under test were compatible with P. fluorescens.