Efficacy of Selected Insecticides for Aphid Control on Cotton, 1997

Cotton was planted on 26 Apr on 30-inch rows near Weldon in Northampton Co., NC. Recommended practices for fertility and weed management were followed. Disyston 15 G at the rate of 0.75 lb (AI)/acre was used at planting for thrips control. On 19 and 28 May, cotton was sprayed with a banded application of 0.25 (AI) Orthene 75 S for thrips control. The banded foliar aphid treatments were applied on 15 Jun via a CO2-pressurized sprayer calibrated to deliver 8.0 gpa at 50 psi with a single TX-8 Spray Systems nozzle 9 inches over the row. Plots were 6 rows X 20 ft with 4 reps and arranged in a RCBD. On 20 Jun, treatments were evaluated by randomly collecting 10 plants in each plot and counting the aphids. On 30 Jun, treatments were evaluated by randomly collecting 10 expanded terminal leaves in each plot and counting the number of aphids. Plots were harvested from the middle 2 rows with a 2-row John Deere picker on 22 Oct. Seed cot-ton yields were converted to lint cotton/acre using 40% gin turnout. All data were analyzed via ANOVA and DMRT.