EVALUATION OF FLUBENDIAMIDE FOR CONTROL OF LEPIDOPTEROUS LARVAE ON FALL LETTUCE, 2006

The objective of the study was to evaluate the efficacy of the new compound Flubendiamide relative to standard materials used against lepidopterous larvae on head lettuce under desert growing conditions. Lettuce was direct seeded on 15 Sep 2006 at the Yuma Valley Agricultural Center, Yuma, AZ into double row beds on 42 inch centers. Stand establishment was achieved using overhead sprinkler irrigation, with furrow irrigation used thereafter. Plots were two beds wide by 45 ft long and bordered by two untreated beds. Four replications of each treatment were arranged in a RCB design. Formulations and rates for each compound are provided in the tables. Sprays were applied on 29 Sep, 7 Oct, 15 Oct, 24 Oct and 6 Nov. The applications were made with a CO2 operated boom sprayer at 50 psi and 19 gpa. A broadcast application was delivered through 3 TX-12 ConeJet nozzles per bed. An adjuvant, Dyne-Amic (Helena Chemical Co.), was applied at 0.125% v/v with all treatments, except Alverde where Penetrator Plus (Helena Chemical Co.), at 0.5% v/v was added. Evaluation of efficacy was based on the number of live larvae per plant. Ten plants per replicate were destructively sampled on each sample date. The sample unit consisted of examination of whole plants for presence of small and large BAW and CL. For BAW, larvae were considered small if < 5 mm in length, large if > 5mm in length. For CL, larvae were considered small if < 10 mm, large if > 10 mm. Treatment means were analyzed using a 1-way ANOVA and means separated by a protected LSD (P < 0.05).