Effects of Selected Seed, Foliar and In-Furrow Applied Insecticides on Thrips Injury, Plant Stand and Yield, 1996

Abstract

Abstract Selected insecticides, applied as seed, foliar or in-furrow treatments, were evaluated against TT injury and for effects on plant stand and yield of Virginia-type peanut. ‘VA-C 92R’ peanut was planted 23 Apr at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA using 36-inch row spacing. Granular insecticides were applied into the seed furrow (IF) at planting with tractor-mounted jars calibrated to deliver exact amounts through lid holes via gravity; liquids with a CO2 pressurized tractor-mounted sprayer calibrated to deliver 5 gpa at 24 psi- through one SS8001E flat fan nozzle per row mounted just above planter disks and turned parallel to the row direction. Foliar sprays were applied in a 12- to 14-inch band over the row with a CO2 pressurized backpack sprayer calibrated to deliver 17 gpa at 22 psi through one 8003E nozzle per row. Seed treatments were prepared just before planting by gently mixing measured amounts of product and seed in the planter box (PB). A RCB experimental design was used with 4 replicates; plots were 4 rows by 40 ft. TT injury was evaluated based on a 0 to 10 scale where 0 = no thrips induced plant injury, 1 = 10% injured leaves, 2 = 20% injured leaves, 3 = 30% injured leaves, 4 = 40% injured leaves, 5 = ≥50% injured leaves + ≤5% terminal buds injured, 6 = ≥50% injured leaves + 25% terminal buds injured, 7 = ≥50% injured leaves + 50% terminal buds injured, 8 = ≥50% injured leaves + 75% terminal buds injured, 9 = ≥50% injured leaves + a90% terminal buds injured, and 10 = dead plants. Plant stand was assessed by counting all seedlings in the 2 center rows of each plot (17 May). Yield was determined by digging, drying and combining peanuts from the 2 center rows of each plot. Data were analyzed using ANOVA and LSD procedures.