In-vitro Assessment of Biocontrol Agents Against Juvenile Mortality of Root-Knot Nematode (Meloidogyne incognita) Infesting Mulberry

Abstract

Root-knot disease caused by Meloidogyne incognita is one of the major diseases affecting mulberry, significantly reducing both the quality and quantity of mulberry leaves. It results in approximately 10–12% leaf yield loss. In-vitro studies were undertaken in the Pathology Laboratory, Department of Plant Pathology, College of Sericulture, Chintamani, to evaluate the efficacy of various bioagents, viz., Trichoderma harzianum, Paecilomyces lilacinus, Lecanicillium lecanii, Bacillus subtilis, Pseudomonas fluorescens, Microbial Consortia 1 (MC1: P. fluorescens + B. subtilis + L. lecanii), and Microbial Consortia 2 (MC2: T. harzianum + P. fluorescens + L. lecanii). Different concentrations of the culture filtrates (25%, 50%, 75%, and 100%) were tested to assess their effects on larval mortality of the nematode at 24, 48, and 72 hours of exposure, in comparison to an untreated control. The experiment consisted of nine treatments replicated three times, following a completely randomized design (CRD). Among the biocontrol agents tested, the highest juvenile mortality (64.33%) was observed at 100% concentration of the culture filtrate of MC1, followed by MC2, which recorded 59.33% mortality at 72 hours after incubation.