Field management of coconut leaf rot disease with biological control agents, their bioformulation and viability in organics

摘要

Leaf rot disease is an integral part of root (wilt) disease of coconut and hence its control a great importance. Potential of biological control agents against leaf rot pathogens have been established. Field performance of talc-based B. subtilis and P. jluorescens against leaf rot (individually and in consortium mode), growth of bioagents in coconut water-based media for enriching bioformulations and viability of the bioagents in organic carriers based formulations were evaluated. A field experimentconducted with treatments of B. subtilis, P. Jluorescens, B. subtilis + P. fluorescens and Phytosanitation + B. subtilis + P. Jluorescens in comparison with control showed a decline of disease index in newly emerged leaves of treated palms (higher disease ameliorative effect through consortium of B. subtilis and P. Jluorescens). Multiplication of bacterial (P. Jluorescens) and fungal (Trichoderma viride) bioagents could be achieved in coconut water-based media - moderate-good growth of P. Jluorescens incoconut water (pH adjusted to 7.0), coconut water amended with peptone at 1 % or jaggery at 5 % or 10 % levels comparable with its growth in King's B broth; moderate-good mycelial yield of T. viride in coconut water-based media with or without jaggery amendment comparable to its growth in potato dextrose broth. The bacterial and fungal biocontrol agents as grown in coconut water-based media could be processed into talcbased bioformulations (quality comparable with such products evolved using conventional media). The talc-based formulations admixed with organics viz., neem cake, vermicompost and coir pith-( 1:1 w/w) that were individually packed also assured reasonable period shelf-life (six months) of bioagents, compared well to corresponding other media. Thus mass production of popular biological control agents in coconut water based medium followed by their bioformulations through fortifications with popular organics has been successfully evolved.