Control of Cabbage Looper on Collards, 1983

‘Vates’ collards were direct seeded in three-row plots 35 ft long on 15 July. Plants were spaced 6 to 8 in. apart in the row and 36 in. between rows. Each two-row plot was buffered by a guard row. The treatments were arranged in a randomized complete block design with four replications. The soil was a Norfolk “A” loamy sand. All spray treatments were mixed in 10 gal of water and applied with a custom-built row crop sprayer. Each row was covered by three drop nozzles delivering 50 gal/acre at 90 lb/in2 Treatments were applied on 17, 24, and 31 Aug. and 7 Sept. Foliage injury ratings ranged from 1 to 5 and were indexed as follows: 1, 0 to 3% damage (odd holes on leaves); 2, 4 to 10% damage (few leaves with holes); 3, 11-25% damage (moderate number of leaves with holes); 4, 26 to 50% damage (most leaves with holes); and 5, 51 to 100 % damage (crown damage and all leaves with holes).