Evaluation of Antimicrobial Activity of Neem Cake and Bio-Agents on Early Blight (Alternaria solani) of Tomato (Lycopersicon esculentum L.)

Abstract

Early blight is the important disease of tomato because it causes huge economic loss to the farmer every year. Alternaria solani cause early blight of tomato and it is considered weed of field because of its wide adaptability under different environment. Use of fungicides for the management of disease in crop puts a large number of negative health and environmental effects therefore, the urgent need for a more sustainable and ecological approach to manage disease without fungicides. To avoid relying solely on chemicals and to identify a viable alternative component,this experiment was conducted to conclude the Evaluation of antimicrobial activity of Neem cake and bio-agents on early blight (Alternaria solani) of tomato (Lycopersicon esculentum L.) by soil application with Neem cake @ 250kg/ha and seedling treatment with bio agents in single and combination viz Pseudomonas fluorescens @10g/lit, Bacillu thuringiensis @10g/lit, Trichoderma viride @10g/lit, Pseudomonas fluorescens@5g/lit +Bacillus thuringiensis @5g/lit, Pseudomonas fluorescens@5g/lit + Trichoderma viride @5g/lit and Trichoderma viride @ 5g/lit + Bacillus thuringiensis @5g/lit both in-vivo and in-vitro for their effectiveness to manage early blight of tomato caused by Alternaria solani .All the treatments were found significantly reduced the severity of the disease and increased growth parameters, Among all the treatments Neem cake@250kg/ha+ Pseudomonas fluorescens @5g/lit + Trichoderma viride @ 5g/lit followed by Neem cake@250kg/ha + Trichoderma viride @5g/lit + Bacillus thuringiensis @5g/lit were significantly superior over other treatments in reducing early blight infection and also in increasing growth parameters of the crop. For in-vitro studies only bio agents were selected among the treatments Pseudomonas fluorescens + Trichoderma viride showed highest mycelia inhibition (89.3%) followed by Trichoderma viride + Bacillus thuringiensis (86.6%). The highest cost benefit ratio was obtained with Neem cake 250kg/ha + Pseudomonas fluorescens @5g/lit + Trichoderma viride @5g/lit treatment (1:3.85). while other treatments also showed significantly effective for the checking of disease intensity and yield over control in the field condition.