One hundred and five okra cultivars were evaluated in the field for resistance to the leafhopper Amrasca biguttula biguttula (Ishida) during the 1989–1990 season. On the basis of nymphal abundance and leafhopper injury index two resistant (Siswal Local and IC 7194) and nine moderately resistant [IC 6653, IC 8899, IC 13617, Sel. 1, HB 94, IC 6316,6 Dhari, Sel. 2–2 and Line 6(1)] genotypes were identified. Both of the resistant, two moderately resistant (Line 6(1) and IC 13617) and two highly susceptible (Pusa Sawani and Pusa Reshmi) genotypes were retested in 1990–1991. Resistant genotypes had significanlty (P < 0.05) fewer nymphs (18.5 to 22.0 nymphs/leaf) and lower values of injury index (2.2) compared with the other varieties. Nymphal duration was also longer (9.3 to 9.8 days) and nymphal survival lower (41.7 to 47.5%) in resistant cultivars. Higher trichome density, longer trichome length and higher concentration of sugars, silica, potassium, tannins and phenols in the leaves of resistant cultivars were associated with resistance to leafhopper.
