Studies on Efficacy of Different Delivery Systems of Pseudomonas fluorescens for Biosuppression of Damping-off Disease in Tobacco Seed Beds

Aexperiment in tobacco nursery was conducted to evaluate effect of different delivery systems for Pseudomonas fluorescens in the management of damping-off in tobacco seed beds. When talc enriched with P.fluorescens was applied, significantly highest population of P.fluorescens was recorded in seed treatment and soil application combination (32.3 x 107 CFUs/g soil) at 60 days after sowing and the same treatment recorded the lowest population of Pythium aphanidermatum (0.52 x 103 CFUs / g soil) of soil. As a result, 33 percent incidence of damping-off was recorded. Application of mancozeb + metalaxyl at 0.2 % recorded 25 percent of disease incidence and the untreated control recorded the maximum disease incidence of 83%. The study suggests that talc based delivery supports better survival of P. fluorescens in rhizosphere when compared to FYM and filter press cake and have potential for controlling Pythium aphanidermatum.