EVALUATION OF INSECTICIDES FOR MANAGEMENT OF FALL ARMYWORM, CORN EARWORM AND SORGHUM WEBWORM ON SORGHUM PANICLES, 2002

Three insecticides, selected because they are approved for use on sorghum, were evaluated to determine rate effects on Fall armyworm (FAW), Corn earworm (CEW) and Sorghum webworm (SWW) attacking grain sorghum panicles at the Mississippi State University Plant Science Research Farm, Mississippi State, MS. Sorghum was planted on 10 May 2002 in 38-inch rows, using the conventional planting system for sorghum in the area. Treatment plots were three rows, 10 ft long, arranged in a randomized complete block design with four replications and a 8-ft alley between replications. Insecticide treatments were applied 1 Aug, using a backpack CO2 sprayer, equipped with a single CONEJET T 3X nozzle, delivering 15 gpa at 40 psi., with water as a carrier for the insecticide. The panicles were in early dough stage. The environmental conditions at application were 70°F, 92% Rh, with sunshine and wind speed of less than 1 mph. Pre-treatment insect counts revealed that larvae of each species were in the midto late instars. Five panicles were collected at random from the middle row of each treatment plot on days 2 and 5 after spray application. Mean number of larvae per five panicles was calculated. Data were analyzed using SAS proc ANOVA, and means were separated using Fisher's least significant differences (LSD).