Evaluation of new biomolecules for combating rice yellow stem borer, Scirpophaga incertulas (Walker), Lepidoptera: Pyralidae; under red lateritic zone of West Bengal

Five new bio-molecules (BM1, BM2, BM3, BM4 and BM5) composed of various natural products with their standard (I) and double (II) dosages along with a synthetic chemical (Fipronil 5% SC) were sprayed at 35 DAT and 65 DAT on paddy. Data on yellow stem borer (YSB) infestation were recorded one day before spraying and 1, 3, 7 and 14 days after spraying. One day before the final harvest, data on various yieldattributing parameters were collected and analyzed. The results concluded that decreasing order of efficacy over control was Fipronil 5% SC > BM3-II > BM2-I > BM4-I > BM3-I > BM5-II > BM1-II > BM5-I > BM2-II > BM1-I > BM4-II in controlling yellow stem borer (DH&WEH). Yield attributing parameters from fipronil 5% SC treated plot showed the highest increase over control. Among the bio-molecules, BM3-II showed better results in all yield-attributing characters except plant height, while BM4-II is the least effective.