Evaluation of bird’s eye chilli landraces against yellow thrips, Scirtothrips dorsalis (Hood.)

AbstractThis investigation aimed to identify indigenous sources of host plant resistance (HPR) by evaluating eighteen local bird’s eye chilli landraces along with three check varieties under natural field conditions. The resistance was quantified using thrips population density (per three young shoots) and the mean leaf curl index (MLCI) across different crop stages. The mean thrips population ranged from 7.07 to 16.08 per three young shoots in rabi and 7.63 to 18.80 in summer, with UASBCF-29 consistently recording the lowest infestation. The mean leaf curl index varied from 19.00 to 65.33% across landraces, with UASBCF-29, UASBCF-27, and UASBCF-30 classified as moderately resistant (MLCI:19.00 - 23.33%). No landrace exhibited complete resistance; however, UASBCF-29 showed the lowest thrips count (7.35 per three young shoots) in both seasons and minimal leaf curl damage (19.50%), indicating strong antibiosis and antixenosis mechanisms. Eleven landraces were susceptible, while six, including the check varieties Byadagi Kaddi and Byadagi Dabbi, were highly susceptible.