EVALUATION OF GAUCHO, CRUISER AND TEMIK, WITH AND WITHOUT AN ADDITIONAL BROADCAST APPLICATION, FOR CONTROL OF THRIPS IN VIRGINIA COTTON, 2002.

Gaucho 600FS, Cruiser 5FS and Temik 15G, with and without an additional broadcast treatment of either Orthene 97 or Karate Z, were evaluated for control of thrips in Virginia cotton. Stoneville 4892 BR cotton was planted 30 Apr at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA, using 36-inch row spacing. In-furrow (IF) treatments were applied into the seed furrow at the time of planting using tractormounted inverted jars with lid holes calibrated to deliver exact amounts via gravity. Gaucho 600FS and Cruiser 5FS seed treatments (seed) were applied commercially. The foliar treatments were broadcast (BC) with a CO2 pressurized backpack sprayer calibrated to deliver 14.3 gpa at 18 psi through 8002VS nozzles spaced 18 inch apart on the spray boom. Foliar applications were made on 17 May at the first sign of true leaf emergence after the cotyledon stage or on 29 May at the 2-3 true leaf stage. A randomized complete block experimental design was used with four replicates; plots were 4 rows x 40 ft. Thrips injury to plants was determined by visually rating injury using a 0 to 5 scale, where 0 = no thrips induced plant injury, 110% injured leaves, no bud injury; 2-25% injured leaves, no bud injury; 3-75% injured leaves, and 0-25% buds injured; 4-90% injured leaves, and greater than 25% buds injured; and 5 = dead plants. Yield was determined by harvesting the two center rows of each plot (80 row ft) using a commercial 2-row John Deere cotton combine. Sub-samples were ginned to determine lint versus seed and trash weight (40% lint, 60% seed and trash). Data were analyzed using ANOVA and LSD statistical procedures.