M. Sivarama Krishna, Y. Srujana, D. Lakshmi Kalyani, K. Venkataramanamma, K. Arun Kumar and K. Mohan Vishnuvardhan
Abstract
Field study on evaluation and comparison of different refugia-in-bag patterns (RIB) against bollworm complex with special reference to pink bollworm was conducted at RARS, Nandyal during 2021 and 2022. Among different RIB patterns evaluated pooled results of two years indicated no significant difference in green boll and locule damage due to pink bollworm among different refugia patterns. Highest yield of 1002 kg/ha was recorded in 20% structured refugia which is statistically at par with all other refugia patterns except in 100% non Bt which recorded lowest yield of 762 kg/ha. Based on foregoing results it clearly states that refugia is longer effective against pink bollworm population which had already developed resistance therefore further development of resistance can be managed in pink bollworm and can be effectively utilized for other bollworm in slowing down the building up of resistance in Bt cotton.