Efficacy of a Granular Insecticide for the Management of Borer Pests of Sugarcane in Sri Lanka

Sugarcane borers (Chilo sacchariphagusindicus and Sesamia inferans ) are a major pest group in sugarcane in Sri Lanka. They have a direct impact on seed-cane production in seed-cane nurseries, as well as on cane and sugar yield, with damages from shoot and stalk bores continuing to increase. Therefore, reinforcing of management strategies have become crucial to reduce the borer population in the existing sugarcane plantations. A field trial was conducted in Siyambalanduwa, Sri Lanka to evaluate six treatments. These included four concentrations of Chlorantraniliprole 0.4% (w/w) G (20, 18, 16, and 14 kg/ha), the current recommendation of Fipronil 0.3% (w/w) GR (18 kg/ha) and an untreated control. The treatments were applied at 55-day> intervals over a period of 5 1/2 months. Chlorantraniliprole 0.4% (w/w) G showed a significant effect on shoot and stalk damages due to borers during both plant and ratoon crops compared to the control. The level of efficacy in controlling was dependent on the concentration used. All four Chlorantraniliprole 0.4% (w/w) was significantly effective over control and Chlorantraniliprole 0.4% (w/w) G 14 kg/ha recorded as highest cost-benefit ratio. No significant effects were recorded on any treatment on plant growth parameters, length of stalk, diameter and brix of the cane at the level of harvesting. Chlorantraniliprole 0.4% (w/w) G 14 kg/ha could be recommended to manage sugarcane borers, with minimum damage for beneficial insects.