Screening of genotypes against cotton leafhopper, Amarasca devastans (Cicadellidae: Hemiptera)

Abstract

Screening trials were executed at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh during kharif, 2016-17 to identify tolerant / resistant genotypes against cotton leafhoppers. A total of eleven genotypes of cotton along with two resistance checks and one susceptible check were screened against leafhoppers and categorized them based on resistance injury index. The peak incidence of cotton leafhoppers was observed at 30 and 60 DAS with 6.0 number/ 3 leaves. While, the incidence was low and below ETL at 90 and 120 DAS in all the genotypes screened. The leaf hopper resistance injury index of varioust cotton genotypes screened had ranged from 1.26 to 3.65. Among all the entries, the lowest resistance injury index was exhibited by the genotype GISV-267 (1.26) and GSHV-173 (1.35). The other genotypes in the order of expressing resistance based on resistance injury index is categorized as GJHV-517 (1.56) > GJHV-497 (1.60) > LHDP-1 (1.68) > CNH-25 (1.72) > CPD-1501 (1.83) > TSH-0533-1 (2.21) > RAH-1069 (2.29) > BGDS-1055 (2.34) > DSC-1501 (2.38) > Bunny Bt (2.57) > Bunny non Bt (2.94) > DCH-32 (3.65).