Role of morpho-physio characters imparting tolerance in cotton sucking pest

Abstract

An experiment was conducted at Cotton Research Unit, Dr. Panjabrao Deshmukh Krishi Vidypeeth, Akola during Kharif, 2016-17. Twenty one cotton genotypes were replicated thrice under Randomized Block Design and evaluated for tolerance against sucking pests. The data were recorded on population of sucking pests/leaves at 45 and 60 DAS. Similarly, the data were also collected on physico-morphic traits like hair density (Trichome) and number of gossypol glands/cm2 to determine tolerance /susceptibility of cotton genotypes against sucking pest.It was observed from present study that those genotypes having more trichome density and gossypol glands/cm2 recorded lower population of aphids, leafhoppers and thrips but population of whiteflies on these genotypes was more indicating role of trichome density and gossypol gland in sucking pest resistance. Highest number of hair density (Trichomes/cm2) was noted in AKH-2013-3 followed by DHY-286, AKH-1523 and AKH-1524. Highest number of gossypol glands/cm2 was noted in genotype DHY-286 followed by AKH-1301 and AKH-2013-3.The correlation studies revealed that the hair density (Trichomes) on leaf of cotton had negative and significant correlation with population of aphids, leafhoppers, and thrips. The hair density (Trichomes) on leaf of cotton had positive and significant correlation with population of whiteflies.