Host Plant Resistance Against Leafhopper (Amrasca biguttula biguttula) and Shoot and Fruit Borer (Earias spp.) in Okra: A Review

Abstract

Host plant resistance against leafhopper (Amrasca biguttula biguttula) and shoot and fruit borer
(Earias spp.) in Okra reveals that the insect pests especially leafhopper and shoot and fruit borer caused
significant losses in Okra yield. Collection, conservation and evaluation of Okra germplasms showed that
resistant, moderately resistant and tolerant genotypes identified and some of them were released as varieties and
practiced by the farmers to get higher yields with low incidence of major pests. Trichomes with high density,
long and perpendicular to leaf surface showed negative correlation to leaf hopper incidence. Okra genotypes
resistant to leafhopper contain more total chlorophyll, xanthophylls, carotene, tannins and silica. High reducing
sugar, non reducing sugars, proteins, free amino acids mixture and pH have positive correlation with hopper
incidence. High oxalic acid acts as feeding deterrent. Accumulation of total carbohydrates and wider sugar
nitrogen ratio were responsible for non-preference to leafhopper. High and long trichomes on the fruit, hinder
the ovipositiion on fruits but high density of hair on leaves facilitate more egg lying. Red coloured, thin and
hard fruits with short calyx, less calyx diameter and thin shoot were found tolerant to borer attack. High tannin,
total phenol, anthocyanin and silica contents were negatively correlated whereas high moisture, total sugars,
reducing and non reducing sugars, proteins and free amino acids were positively correlated with borer
infestation in okra genotypes .High Fibre and ash content in fruits were significantly negatively correlated with
the infestation of E. vittella.