Efficacy Of The Bollgard Gene In Transgenic Cotton Lines Against Bollworm And Tobacco Bud-Worm, 1993

Efficacy Of The Bollgard Gene In Transgenic Cotton Lines Against Bollworm And Tobacco Bud-Worm, 1993 Transgenic cotton lines expressing an insecticidal protein produced by a modified crylA(c) gene from Bacillus thuringiensis kurstaki (i.e.. Bollgard Gene, Monsanto Company) were planted 17 May near Corpus Christi, Texas. Field plots were 4 row (38 inch centers) X 30 ft. Treatments (i.e., cotton lines) were arranged in a split plot RCBD and each plot replicated 6 times. The main plot was lepidopteran control (i.e., unsprayed or sprayed with Karate (0.03 lb|AIJ/acre) and Curacron (1.0 lb[AI]/acre) to control tobacco budworm, bollworm and other lepidopteran pests) and subplots were 7 cotton lines. Plots for lepidopteran suppression were sprayed on 16, 22, 29 Jul, 5, and 13 Aug with Karate and Curacron using a backpack CO2 powered sprayer and a 2-row handheld spray boom. The entire test was planted with in-furrow insecticide and oversprayed as needed for in-season control of insect pests. such as thrips, aphids, boll weevil and cotton fleahopper. Efficacy of transgenic Bollgard cottons against target lepidopteran pests was determined by ex-amining 20 flower buds and 20 bolls per plot on 14, 21, 28 Jul, 4, and 12 Aug for bollworm-tobacco budworm feeding injury, and taking lint yields/plot. Supplemental soil moisture was provided by sprinkler irrigation during the season but not within 48-h following a lepidopteran control application. The plots were hand-harvested (40 ft from middle 2 rows) and seedcotton ginned on a laboratory 10-saw gin.