Management of Internode Borer Chilo Sacchariphagus Indicus (Kapur) by Trichogramma Chilonis Ishii: Appraisal of Weekly Releases at Increased Doses

Four field trials were conducted to assess the efficacy of weekly releases of Trichogramma chilonis Ishii at double the recommended dose i.e. 50,000/ha (2.5 cc/ha), 5 cc/ha and higher dose 12.5 cc/ha for managing the internode borer (INB), Chilo sacchariphagus indicus (Kapur). Results indicated that there was a significant reduction in incidence and intensity of INB damage resulting in significantly higher yields in parasitoid-released plots over control plots. Releases at 12.5 cc/ha resulted in the highest reduction of INB incidence (29.95%) and intensity of damage (29.41%) over control plots. Yields were consistently higher in parasitoid-released plots with 13.29 to 25.89% increase over control plots. The pooled cost benefit analysis showed that releases at 5 cc/ha was more gainful (1: 6.5) than 12.5 cc/ha (1:2.4).