Development of an integrated approach for managing root-knot disease on chili {Capsicum annum L) under field conditions

Abstract

A 2-year field study was conducted to develop a field application method using eco-friendly means for controlling root-knot disease of chili. The test sites at the Indian Institute of Vegetable Research, Varanasi, UP, India were heavily infested (up to 5.2 juveniles g -11 soil) with root-knot nematode, Meloidogyne incognita. As a pretreatment, three deep summer ploughing at 15 days interval caused a reduction of 53.8% of the initial population levels of M. incognita. The integration of soil amendment (neem cake at 20 t ha -1), seed treatment (6 g kg -1 seed) and/or soil application with a talc preparation of fungal biological control agents (Pochonia chlamydosporia (2x10 7cfu g -1) at 12 kg ha -1 and Trichoderma viride (2.8x10 6cfu g -1) at 12 kg ha -1 were tested. Neem cake was applied 10 days prior to sowing seeds in nursery beds and/or application of biological control agents to the main field as and when required as per experimental layout. Application of any of the tested components significantly reduced the incidence of root-knot disease in both years compared with the controls. Combined applications of any two components caused better recovery in plant health compared with individual treatments and/or controls. The best protection of disease, in terms of reduction in number of galls (58%) and reproductive factor (P f/P i (R) = 0.3), was achieved through integration of neem cake, P. chlamydosporia and T. viride (reduced half dose). It also enhanced marketable chili yield by up to 54%. Re-isolation of both fungi at harvest showed that they were successfully established in the rhizosphere of chili plants up to the termination of experiment.