Evaluation of Aphid Control in Lettuce with Admire Applied Through Drip Irrigation
Abstract Lettuce was direct seeded on 29 Nov at the Yuma Valley Agricultural Center, Yuma, AZ. into double row beds on 42 inch centers and stand establishment achieved using overhead sprinkler irrigation. Subsequent irrigations and chemigations were made with sub-surface (6-8”) drip irrigation. Plots consisted of 4 beds, 50 feet long with a two bed buffer between the plots. Plots were arranged in a RCB design with four replications. The four Admire 2F chemigation treatments were applied once 54 d after planting (23 Jan) through the drip system during the last hour of the irrigation run. The two Metasystox-R chemigation treatments were applied through the drip three times on 23 Jan, 1 and 8 Feb. The foliar Metasystox-R + Capture treatment was applied at 60 PSI in 20 gpa total volume on 23 Jan, 1 and 8 Feb. Insect data were collected only from the inner two beds of each plot. Aphid densities were estimated bi-weekly by sampling 10 plants per replicate and counting the total number of aphids per plant. Data were analyzed as a 1-way ANOVA using a protected LSD F test to distinguish treatment mean differences.