Influence of high density planting and genotypes on major pests and diseases in rainfed cotton

Abstract

Field trial to study effect of high density planting of G. hirsutum genotypes on incidence of various pest and diseases of cotton was conducted at Nanded (M.S.) for three consecutive seasons (Kharif, 2013-14 to 2015-16). The incidence of sucking pests, especially leaf hoppers was increased at 75 DAS and white flies at 75 DAS and 120 DAS in closer spacing of 45 x 10 cm (density 2.22 lakh plantha-1) over wider spacing 75 x 10 cm (1.11 lakh plantsha-1). The boll damage due to H. armigera and locule damage due to P. gossypiella was almost similar in all the plant densities. Alternaria leaf spot disease was found with significant intensity in closer spacing (2.2 lakhha-1) over wider (1.11 lakhha-1) whereas, different HDPS spacing didn’t influenced incidence of bacterial blight and grey mildew. The closer spacing, 60 x 10 cm (density 1.66 lakhha-1) and 45 x 10 cm (density 2.22 lakhha-1) were significant over wider spacing 75 x 10 cm (density 1.11 lakhha-1) for seed cotton yield. Sucking pest incidence was lower in hirsutum cotton genotype NH 615 and Suraj at various stages. The incidence of bollworms (fruiting body and locule damage) was almost similar in all the varieties. Variety NH 615 was observed with lowest grey mildew intensity. Varieties NH 615 and NH 635 performed better under HDPS for seed cotton yield.