Control of Imported Cabbageworm and Cabbage Looper Using Pyrethrin, Rotenone, or Asana with or Without One of Four “Synergists,” 1987

The experiment was located in a commercial transplanted cabbage field near Belle Plaine, Minn. Plots were two 38 inch rows, 25 ft long, replicated 4 times, and arranged in a randomized complete block. Insecticide applications were made on 28 Jul with a handheld CO2 sprayer using 40 psi pressure and 17 gal total material/acre. Temperature at application was 90°F. Numbers of living and dead larvae were counted on 5 plants 24 h posttreatment in reps 1 to 3 and 48 h posttreatment in rep 4. Larval counts were converted to % control, transformed using ARCSINE, and the means were compared. Phytotoxicity was observed particularly due to Rotacide earlier, so a l-to-3 scale was used, with the most intense purple and brown cabbage discolorations considered a 3.