Corn Earworm Control in Peanut in Virginia, 1991

Efficacy of selected insecticides was evaluated against CEW in 'NC 7' Virginiatype peanut in Suffolk, VA. Peanuts were planted 6 May using a 36-inch row spacing. Temik 15G at 1 lb (AI)/acre was applied in-furrow at planting. Test treatments were applied on 9 Aug using a COa pressurized backpack sprayer calibrated to deliver 14.5 gal formulation per acre at 50 psi through three D2- 13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A randomized complete block experimental design was used with 3 replicates; plots were 4 rows by 40 ft. Treatments were evaluated before and 3, 6, 10 and 13 DAT by comparing numbers of small, medium, and large-sized CEW larvae per 3 row ft, corresponding to lst-2nd, 3rd-4th and 5th-6th instar groupings, respectively. Pretreatment means were determined from four 3 row-foot samples per replicate taken before treatments were applied. Yield was determined by digging, combining (8 Oct), drying, and weighing peanuts from the 2 center rows of each plot. Data were analyzed using ANOVA and LSD statistical procedures.