Control of Lepidopteran Pests in Cabbage, 1996

This study was conducted at the University of Minnesota Rosemount Agricultural Experiment Station. Cabbage was transplanted bare-root on 28 Jun. Plots consisted of two 25 ft (7.6 m) rows on 40 inch (1.0 m) centers with plants spaced 13 inches (0.33 m) apart. Ten ft (3.0 m) borders and 10 ft (3.0 m) alleys separated plots. Treatments were arranged in a RCB design with 4 replications. Treatment applications were initiated during the 9-12 true leave stage, before precupping. Treatments were applied 26 and 31 Jul, 08, 14 and 21 Aug using a moderate-clearance Spirit sprayer with 3 TX-10 hollowcone nozzles (1 overhead and 2 drop nozzles) per row. The sprayer was calibrated to deliver 27 gpa (252.5 liters/ha) at 47 psi (3.3 kg/cm2) and 3 mph (4.8 km/hr). Bond sticker/extender was added to all treatments (except Confirm treatments) at a rate of 0.10 fl oz/gal (0.8 ml/liter). Counts were taken from 5 heads per plot on 15 Aug and 10 heads per plot on 26 Aug. Ten heads per plots were evaluated for feeding damage on 30 Aug using Green’s rating scale (J. Econ. Entomol. 1969 62:4 798-800): 1 = no feeding damage; 2 = minor feeding damage on the wrapper leaves (1 % eaten); 3 = moderate feeding damage on the wrapper leaves (2–5% eaten) with no head damage; 4 = moderate feeding damage on the wrapper leaves (6-10% eaten) and minor feeding scars on the head; 5 = moderate to heavy feeding on the wrapper leaves (11-30% eaten) and moderate feeding scars on the head; 6 = >30% of the wrapper leaves eaten and numerous feeding scars on the head.