EFFECT OF BIOLOGICAL AND CHEMICAL TREATMENTS ON ROOT ROT INCIDENCE ON COWPEA AND RELATIONSHIP WITH CLIMATIC PARAMETERS

Abstract

Studies were conducted to ascertain effect of biological and chemical treatments on dry root rot of cowpea caused by Macrophomina phaseolina at four different climatic regions (central zone, north east, hill zone and north western plains) of the India with impact of three sowing dates and climatological parameters. Field study conducted for two years provided three different types of recommendations for 4 locations comprises sowing dates and treatment types. In general, least disease incidence was recorded in the treatment having seed treatment with tebuconazole + NSKP followed by foliar spray of propiconazole except at Jhansi. Incidence of root rot was regressed with climatic variables quantified through average rainfall, relative humidity, sunshine duration, angle and temperature variables. The data interpreted by different statistical analyses indicated that root rot incidence in cowpea was significantly affected by spatial, temporal and treatment factors as well as by their interaction. PCA technique provides a multivariate control on this disease and several regression equations were established between root rot incidence and energy variables. Our approach provided a novel method for managing dry root rot during vegetative or fruiting stage based on climatic parameters.