Use of Imidacloprid (Admire 2F and Provado 1.6 F) to Control Green Peach Aphid in Lettuce, 1995

Lettuce was direct seeded into double-row beds on 11 Nov at the Yuma Valley Agricultural Center, Yuma, Az. Each plot consisted of four, 70 ft long beds spaced 42 inches apart and bordered on each side by an untreated bed. Plots were arranged in a RCB design with 4 replicates. The Admire 2F treatments were applied 2 in. sub-seed furrow by injecting the material into the beds with long, narrow shanks before seeding. The Admire sidedress treatment was applied 3-4 in. into the soil 60 days after planting. All Admire treatments were applied with water and delivered at 20 gal/acre total volume. Foliar applications of Provado and MSR + Capture were made on 24, 27 Jan and 4 Feb with a CO2-powered backpack sprayer with a two-bed boom, having two nozzles per bed (TX 12 hollow cone), and delivering 20.5 gal/acre at 40 psi. Aphid numbers per plant were estimated on 20 Dec, 3, 19 Jan, and 2, 16 Feb by collecting 15 plants per plot and counting the total number of aphids present on each plant. Aphid infestations at harvest (20 Feb) were estimated by recording the percentage of plants infested with >0 and >10 aphids on wrapper leaves and heads. Because of heterogeneity of mean variances, insect data was transformed (log10 x + 1) prior to analysis. Treatment differences among means were estimated with the Ryan-Einot-Gabriel-Welsch multiple F test.