Evaluation of Biological Alternatives for Early Season Tobacco Budworm Control in Southern North Carolina, 1995

Cotton was planted on 4 May in a Norfolk loamy sand on 38-inch rows near Laurel Hill in southeastern NC. Recommended practices for fertility and weed management were followed, and 0.75 lb (AI)/acre Temik 15G used at planting for thrips control. Plots were 40 ft X 6 rows, with 10-ft alleys and 4 replications arranged in a RCBD. The entire test was oversprayed with 1.0 lb (AI)/acre Orthene 75S on 7 Jun to encourage TBW establishment via destruction of beneficial arthropods. All applications were applied with a CO2-pressurized back pack sprayer calibrated to deliver 8 gpa at 50 psi with a single Spraying Systems TX-8 hollow cone nozzle per row. The Ovasyn plots were sprayed on 7, 14 and 21 Jun and the Design plus Ovasyn and the Larvin treatment was sprayed on 14 and 21 Jun. On 26 Jun, all squares and terminals from one of the treatments were removed by hand. A second removal treatment consisted of the 3 earliest squares being removed from each plant on 7 Jul. On 26 Jun, 25 terminals from each plot were examined for TBW eggs, terminal damage from TBW and live larvae. No squares were present at this relatively late date and thus were not sampled. On 31 Jul, the number of white blooms and bolls was counted for 15 ft for each plot per replicate (60 ft total per treatment). As an index of maturity, on 25 Oct the number of green and opened boll from 15 row ft were counted for each plot. The test was harvested with a 2-row John Deere mechanical harvester on 18 Oct.