Foliar-Applied Rescue Treatments for Army and Pale Western Cutworm Control in Winter Wheat, 1993

Abstract

A winter wheat field near Murdo, SD, was chosen for this experiment. Pretreatment counts indicated that the field was naturally infested with an average of 2.4 live cutworm larvae per 2 ft2. The study involved a performance comparison of 12 insecticide treatments with an untreated check. A RCBD replicated 3 times was used. Pretreatment infestation level was used as the blocking criterion. Treatment plots were 30 × 30 ft sections of winter wheat separated by 3-ft alleys on all sides. Insecticide applications were carried out (14 May) using a CO2-propelled backpack canister sprayer system and a 6-ft boom equipped with 4, TeeJet 8002 flat fan nozzles delivering 20 gpa at 30 psi. Live cutworm counts were conducted at 6 DAT (20 May) to determine insecticide efficacy. A sample consisted of randomly selecting a 2 linear ft section of wheat within a row, then sifting ca. 2 inches deep through a 6-inch wide swath of soil including, and on either side of the row. Two samples were taken from each quadrant within a plot (i.e., a total of eight 2 ft2-samples were taken randomly from each plot). Cutworm count data were analyzed via SAS’s General Linear Models (GLM) procedure and means were compared using Duncan’s Multiple Range Test.