In-vitro Evaluation of Antagonistic Activity of Native Trichoderma spp. and Pseudomonas fluorescens Isolates against Alternaria solani Causing Early Blight of Tomato

Abstract

The present study was carried out in 2018-2019 at Department of Plant pathology, SASRD, Nagaland University to evaluate the in vitro efficacy of 24 native isolates of Trichoderma and 18 isolates of Pseudomonas against Alternaria solani by dual culture technique method. The test pathogen was isolated from disease infected tomato plants collected from an experimental field of Department of Plant pathology, SASRD, Medziphema campus. The results showed that all the isolates had significantly inhibited the mycelial growth of the pathogen. The highest inhibition of mycelial growth of A. solani was shown by T-5 (73.34%) followed by T-11(70.23%). The lowest inhibition was shown by T-24 (51.55%). Among the Pseudomonas isolates, highest inhibition in mycelial growth of A. solani was shown by P-7 (77.73%) followed by P-12(76.00%) respectively.  The lowest inhibition was shown by P-17 (53.78%). The results indicate that different local isolates of Trichoderma spp. and Pseudomonas fluorescens were effective against the tested pathogenic fungi which provides their potential in biological management of early blight disease of tomato.