Efficacy of Bio-agents against Pythium aphanidermatum in vitro

Six antagonists viz., Trichoderma viride, Trichoderma harzianum, Trichoderma virens, Pseudomonas fluorescens, Bacillus subtilis and Pseudomonas putida were studied for their antagonism against P. aphanidermatum by dual culture method. Significantly reduced the mycelial growth of the pathogen over control. Significantly maximum inhibition of mycelial growth of the pathogen after 72 hrs. of incubation was obtained with Bacillus subtillis (70.44%). The next best antagonist in order of merit was Trichoderma harzianum (62.55%). It was followed by Trichoderma viride (54.22%) and Pseudomonas peutala (53.33) which were at par with each other. The next best treatment in order of merit was Pseudomonas fluroscences (50.77%). Minimum per cent growth inhibition (42.11%) was recorded in Trichoderma virens. In present findings bacterial bioagent viz. Bacillus subtilis was found most effective to inhibit the Pythium aphanidermatum.