Ecofriendly management of root knot nematode, Meloidogyne incognita in okra (Abelomoschus esculentus (L.) Moench) through integrated application of oil cakes and bioagents

Abstract

The production of okra (Abelomoschus esculentus (L.) Moench), one of the important vegetable crops cultivated in India is limited by root knot nematode, Meloidogyne incognita infestation. A field experiment was carried out during kharif, 2017 to evaluate the efficacy of oil cakes (neem and jatropha oil cakes) and bio control agents (Purpureocillium lilacinum, Trichoderma viride and Pseudomonas flourescens) in various combinations against this nematode infecting okra. This experiment comprising of eight eco friendly treatments along with a chemical standard check (Carbofuran 3G @ 1kg a.i/ha) and an untreated check, which were replicated thrice following Randomized Block Design. During harvest, observations on plant growth and root knot nematode reproduction were taken. All the treatments recorded a significant increase in plant growth and decrease in nematode reproduction over untreated check. Among all the management treatments, soil application of jatropha oil cake @ 1.0 t/ha 15days before sowing + seed treatment with T. viride + P. fluorescens, each @ 5g/ kg seed + soil application of P. lilacinum @ 2.5kg/ha 15days after sowing was the most effective integrated combination which recorded the maximum increase in plant height (68.1%) , root length (95.3%), fresh shoot weight (57.0%), fresh root weight (92.8%), shoot dry weight (90.9%), root dry weight (77.5%), biomass yield (87.6%) and fruit yield (65.5%) with maximum reduction in number of galls per plant (84.7%), number of egg masses per plant (88.3%), number of eggs per egg mass (48.3%), nematode population (81.1%) and root knot index (34.0%) over untreated check followed by soil application of neem oil cake @ 1.0 t/ha 15days before sowing+ seed treatment with T. viride + P. fluorescens, each @ 5g/ kg seed + soil application of P. lilacinum @ 2.5kg/ha at15days after sowing.