Biophysical basis of resistance in okra to jassids, Amrasca biguttula biguttula (Ishida)

Abstract

Evaluation of biophysical parameters of okra germplasm for resistance or susceptibility to jassids Amrasca biguttula biguttula (Ishida) was conducted at the All India Coordinated Research Project on Vegetable Crops, Odisha University of Agriculture and Technology, Bhubaneswar during kharif 2018 and summer 2019. The results revealed that the plant height, number of leaves, leaf area, leaf thickness, and trichome length and density of 50 okra germplasm varied from 73.45 to 129.93 cm, 10.50 to 24.00 leaves/ plant, 203.70 to 389.25 cm2, 0.40 to 0.96 mm, 0.38 to 0.96 mm and 3.50 to 10.25 trichomes/ cm2, respectively. The plant height, number of leaves and leaf area showed positive correlation with incidence, whereas leaf thickness, trichome length and trichome density exhibited negative correlation. The okra germplasm BBSR-37, BBSR-36 and BBSR-57 were found to be resistant, while Pusa Sawani, BBSR-53 and BBSR-18 were observed to be susceptible.