Insecticide Evaluation Against Mexican Rice Borer on Sugarcane, 1987

Plots of 4 rows (1.5-m centers) × 19.8 m (0.012 ha) l of 2nd ratoon sugarcane, clone 'TCP81-3072,' were located in Hidalgo County, near Santa Rosa, Tex. A buffer of 3.0 m of standing cane was left between plots. Spray concentrations were applied in a randomized block design at 70 psi in 7.6 liters of water (25.6 liters water/ha) using a ground sprayer with a 6.1- imboom with 1 nozzle on either side and the top of each row of sugarcane. Nozzles on the sides of the cane were lowered 0.9 m into the canopy and directed toward the plants. Formulations of San 353 and 354 were applied immediately prior to applications of conventional insecticides. Prespray counts of bored jinternodes and stalks containing infested leaf sheaths (25 stalks/plot) were made 26 Aug and 9 Sep, respectively. Treatments were applied to all plots on 11 Sep and on 18 Sep to plots of treatments with leaf sheath infestations exceeding 10% (current action threshold), 3 days after the initial treatment. Posttreatment counts of infested leaf sheaths were made on 14, 21, and 25 Sep and 2 and 8 Oct, whereas bored internodes were estimated on 8 Oct. Data were analyzed using analysis of covariance and least-squares means due to significant pretreatment means.