Quantitative reduction in canes, juice, bagasse and qualitative deterioration in juice of sugarcane at different intensities of damage by Plassey borer was determined. An average decrease in cane weight, juice weight and bagasse weight in damaged canes over healthy ones was recorded to the tune of 28.0, 29.6 and 24.0%, respectively with 1 to 8 damaged internodes; the maximum decrease being 28.0% of cane weight, 42.5% of juice weight in canes with 7 damaged internodes and 33.3% of bagasse weight in canes with 5 damaged internodes. Damage intensity with 6 damaged internodes was found to cause the maximum deterioration in juice quality followed by 8 damaged internodes. A maximum reduction in brix, pol, sucrose, glucose, and CCS was 14.1, 19.5, 18.4, 58.1 and 20.4%, respectively. An average reduction of 9.7% in brix, 13.7% in pol, 12.6% in sucrose, 42.9% in glucose and 13.9% in CCS was observed under different damage intensities. The variations in the level of deterioration in juice quality and the weight of canes, juice and bagasse were attributed to variations in number of larvae feeding the internode's tissues.
Chilo tumidicostalis, Juice quality, Saccharum officinalis
