Efficacy of Selected Insecticides Against Bollworms on Cotton, 1997

Cotton was planted on 12 May in 38-inch rows at the Upper Coastal Plain Research Station near Rocky Mount in central North Carolina. The fertility and herbicide programs followed extension recommendations for cotton in this region. Temik at 5.0 lb (AI)/acre was used at planting. Plot size was 50 ft X 6 rows with 4 replications arranged in a RCBD. Insecticide applications were applied on 20 and 26 Aug with a backpack-type, CO2-pressurized sprayer calibrated to deliver 8.0 gpa at 50 psi with a single TX-8 Spray Systems nozzle 18 inches over the row. All treatments were evaluated for fruit damage and live caterpillars on 2 and 26 Sep. Twenty-five squares and bolls were examined for BW, FAW, and ECB damage and live larvae per replicate (total 100 per treatment). Plots were harvested from the middle 2 rows with a 2-row John Deere picker on 23 Oct. Seed cotton yields were converted to lint cotton/acre using 40% gin turnout. All data were analyzed by ANOVA and DMRT.