Exploitation of Pseudomonas fluorescens for the Management of Damping-off Disease of Tobacco in Seedbeds

Six bacterial antagonists viz., Pseudomonas fluorescens (Pf)-1(NI), Pf -2(NI), Pf -3(NI), Bacillus sp.-1, Bacillus sp.-2 and Pf-TNAU isolates were evaluated in vitro for the management of damping-off disease in tobacco seedbeds caused by Pythium aphanidermatum (Edson) Fitzp. All the antagonists were antagonistic to the pathogen. Pf -1(NI) showed highest growth inhibition (48.3%) of P. aphanidermatum followed by Pf -TNAU (42.8%) over control. Seed treatment with Pf -1 @1 g/m² seed bed and metalaxyl plus mancozeb recorded lowest number of Pythium affected seedlings and was on par with copper oxychloride. Significantly higher number of transplants was recorded in the seed treatment with P. fluorescens. The efficacy of this bacterium was equivalent to the standard fungicide metalaxyl + mancozeb.