Cabbage Looper Control on Head Lettuce, 1977

Tests were conducted on ‘Empire’ head lettuce grown on Laveen clay loam at the University of Arizona, Mesa Branch Station. Pelleted seed was planted in a dry seed bed on August 25, 1977, with a Stanhay precision planter. Planting was on 40-inch-wide beds with 2 seed rows per bed. Plots were 4 beds wide by 25 ft long and replicated 4 times in a randomized complete block. Sprays were applied with a CO2-pressurized back-pack sprayer, operating at 55 psi and applying 35 gallons of spray mixture per acre. Initially sprays were applied with a boom having 1 hollow-cone nozzle per plant row. As the plants became larger, 2 hollow-cone nozzles per row were used for better coverage. Sprays were applied on September 20, 27, October 4, 13, 20, and 27. All plots were treated on September 6, with Lannate at 0.45 lb ai/acre to protect the seedling stand. Insect counts for cabbage looper eggs and larvae were made by examining 10 plants picked at random from the middle 2 beds of each plot.