Insect Growth Regulators for Control of Colorado Potato Beetles in Potatoes, 1987

Superior' white potatoes were planted on 14 Apr in a Sassafras sandy loam field. Plots consisted of 3 rows of potatoes, each row 25 ft long and 3 ft wide, arranged in a randomized complete block design with 4 replications. Treatments were applied with a self-propelled, high-clearance sprayer with 1 drop nozzle on each side of the row and 1 over the center of each row calibrated to deliver 68 gal/acre at 40 psi. Treatments were applied on 5 and 16 Jun. Percent plant defoliation was recorded on 15, 23, and 29 Jun. Numbers of CPB larvae per 5 hills were recorded on 15 Jun. Plots were harvested and yields (cwt./acre) were recorded on 5 Aug.