Evaluation of Bioagents against Stemphylium vesicarium Inducing Stemphylium Blight in Onions (Allium cepa L.)

Abstract

Stemphylium blight of onion incited by S. vesicarium is one of the economically important diseases, causing severe yield losses in onion crop. The present investigation was carried out to evaluate efficacy of different bioagents against S. vesicarium under in vitro conditions. The experiment was laid out in a Completely Randomized Design (CRD) with three replications per treatment. Five fungal biocontrol agents viz., Trichoderma harzianum, T. viride, T. hamatum, T. virens and a fungal consortium from MPKV, Rahuri along with two bacterial biocontrol agents namely Pseudomonas fluorescens and Bacillus subtilis were evaluated for their effectiveness against S. vesicarium. The results showed significant variation in the inhibitory effects of bioagents on the mycelial growth of the test pathogen with percent growth inhibition ranging between 53.70 to 85.19 per cent. T. harzianum was reported to be most effective, showing a minimum colony diameter of 13.33 mm with the highest growth inhibition (85.19%) thus reported as superior to all other treatments whereas, Pseudomonas fluorescens was reported with a least percent growth inhibition (53.70%).