Control of Diamondback Moth on Spring Planted Cabbage—Ii, 1990

Cabbage was direct seeded in double rows into prepared seedbeds on 2 Apr at the Sweet Potato Research Station near Chase, La. The plots consisted of 3 seedbeds (6 rows) on 40-inch centers by 30-ft long, with only 2 seedbeds being treated. Treatments were arranged in a completely random design with 4 replicates. Test materials were applied using a hand-held boom with a CO2 charged delivery system calibrated to deliver 30 gal total spray/acre through Teejet 8002 flat-fan nozzles (2/seedbed) at 48 psi. Applications were made on 11, 17, 24 May and on 1, 6 Jun. Treatment efficacy was evaluated by sampling 5 plants/plot on 14 and 21 May. Plots were harvested (15 heads/ plot) on 19 Jun to determine quality and damage ratings. Foliage injury was rated using a scale from 1-6 (1 = no apparent feeding, 6 = severe damage to head and wrapper leaves). Plants with a damage rating of 3 or below were considered to be marketable. Overhead irrigation was provided on an "as needed" basis to the test plots, but not within 72 h posttreatment.