Potato Tuberworm Control in Potatoes, 1980

An experimental potato planting (Kennebec variety) was made on Jun 3 at Moreno Valley Field Station, Riverside, CA. Insecticide treatments were replicated 4 times in a randomized complete block design. The replicates were 8 rows wide (32-inch centers) by 70 ft long with a 5-ft buffer between replicates. Insecticides were applied at 2-wk intervals from Jul 31 through Oct 9 (6 applications). Insecticides were applied by handheld spray equipment (Arimitsu sprayer) with 3 nozzles per row at an operating pressure of 50 psi and delivery rate of 20 gal/acre. Nozzles were hollow cone, Dl orifice, 13 core and 50-mesh screen. All treatments included 0.04% spreader/sticker (Biofilm). Five stems/ replicate were inspected weekly from Aug 6 through Sep 19 for larvae and mines without larvae. The 2 center rows/replicate were harvested on Oct 22. Tubers were inspected for potato tuberworm damage. Data was analyzed by Duncan’s multiple range test at 5% level of probability. ‘An arcsin transfor-mation was performed on the percent infested white tuber data before analysis.