Biocontrol agents against early blight (Alternaria solani) of tomato

Abstract

Biological control agents are the best alternative to the hazardous chemical fungicides and other agro chemicals. Various biological control agents viz., Trichoderma viride, Pseudomonas fluorescens and Bacillus subtilis were evaluated against Alternaria solani (Ellis and Martin) Jones and Grout causing early blight of tomato resulting in severe yield loss. All treatments showed the varied antifungal activity against the pathogen. Among the in vitro screened biological control agents percent growth inhibition of pathogen was higher in Trichoderma viride (77%). Plant biometric observations viz., seed germination (89%) and seedling vigor (1994) was maximum with lower percent disease index (16%) was recorded in Trichoderma viride treated seeds and seedlings of tomato cultivar PKM 1.