Cotton Aphid Control, 1993B

Insecticides were evaluated for relative efficacy against cotton aphid in nonirrigated cotton planted 6 May at Stoneville, MS. Plots of 8 rows (40 inch centers) by 65 ft, separated by 15 ft alleys, were arranged in a RCBD with 4 replicates. All treatments were applied by a high-clearance spray machine equipped with a compressed air spray system. Total spray volume was 6 gpa at 5 mph and 35 psi using 2 TX10 nozzles/row. Plots within a replicate were sprayed consecutively with the boom rinsed twice and blown clear between plots. Treatments were applied on 6 Jul. Efficacy was determined by counting aphids per square inch on leaves in the top, middle, and bottom third portions of 40 randomlychosen plants 1 h before initial treatment and at 3, 7, and 14 DAT.