Evaluation of Insecticides and Insecticide Combinations for Aphid Control on Cotton in the Mississippi Delta, 1987

Eight treatments were tested for relative efficacy against cotton aphid in irrigated cotton planted 5 May at the Delta Branch Experiment Station, Stoneville, Miss. Plots were 8 rows (40-inch centers) × 50 ft and were arranged in a randomized complete block design with 4 replications. Treatments were applied to the center 4 rows by high-clearance spray tractor equipped with a compressed-air plot spray system calibrated for 3.3 gal/acre at 4 mph using 2 TX-3 nozzles/row. Applications of insecticide were made on 16 Jul. All plots received insecticide treatments for nontarget pests as needed during the season. Aphids were counted on each of 10 leaves picked at random from about the 4th node from the terminal in each plot. All data were collected from the center 2 rows. Yield was obtained by use of a mechanical picker.