Evaluation of the Fermentation Byproduct Spinosad and Conventional Insecticide Treatments for Controlling Sunflower Beetle Larvae, 1996

Abstract A commercial sunflower field near Mina, in north-central South Dakota, was selected foi our trial of several insecticide treatments at standard and reduced rates for management of SB larvae. The experiment was arranged in a RCBD with 4 replications, and individual treatment plots were 25 ft long by 10 rows (38 inch spacing) wide. In addition, each plot was bordered by two buffer rows to prevent drift. Pre-application evaluations were carried out using whole-plant visual counts of the number of live SB larvae per plant. Twenty plants were examined from each treatment plot and these counts indicated an average of 11 SB larvae per plant within the test area. Treatments were applied on 11 Ju’ using a CO2-propelled backpack sprayer system with a hand-held 6.7-ft long boom. The boom was equipped with 4 TeeJet 8001 nozzles spaced 20 inches apart, and was calibrated to deliver a spray volume of 15 gpa while traveling at 3 mph. Insecticide efficacy was evaluated at 6 DAT using the same count ing technique and number of samples described for pre-application sampling. Data were analyzed with SAS’ s General Linear Models procedure and means were compared using DMRT.