Efficacy of two Pyrethroids Employed at Traditional and Extended Spray Intervals Against Fall Armyworm, Bollworm and European Corn Borer in North Carolina, 1993

Abstract

Abstract Cotton was planted in a Wagram loamy sand on 10 May near Richlands, NC. The fertility and weed management programs followed NCSU recommendations with 0.6 lb (AI)/acre Temik 15G applied in furrow at planting. Plot size was 6 rows (38 inch centers) × 50 ft with 10 ft alleys. A RCBD was used with 4 replicates. Treatments were applied via a backpack-type CO2-pressurized sprayer calibrated to deliver 8 gpa at 50 psi with a single TX-8 Spraying Systems nozzle per row. Initial application for all treatments, based upon exceeding a threshold of 10 eggs per 100 terminals, was made on 22 Jul. The second application for the Baythroid 0.028 lb (AI)/acre, regular start treatment was made on 27 Jul, while the Baythroid at 0.045 lb (AI)/acre regular start treatment received only the initial application. The Baythroid at 0.028 lb (AI)/acre, scouting-based plot was treated on 22 and 27 Jul and on 4 and 19 Aug. The Baythroid at 0.045 lb (AI)/acre, extended, 14-d interval plot was treated on 22 Jul and on 4 and 19 Aug. A final Baythroid 0.028 lb (AI)/acre, extended, 14-d interval treatment was likewise applied on 22 Jul and on 4 and 19 Aug. Karate at 0.025 lb (AI)/acre was also treated at a scouting-based schedule of 22 and 27 Jul and 4 and 19 Aug, and the same material at 0.04 lb (AI)/acre on the extended 14-d interval was applied on 22 Jul and on 4 and 19 Aug. All plots were evaluated for FAW, ECB and BW-damaged bolls on 17 Aug and 15 Sep. Plots were harvested with a 1-row John Deere mechanical picker from the middle two rows on 13 Oct.