Insect Control on Flue-Cured Tobacco with Systemic Insecticides, 1996

Abstract

Abstract This experiment was conducted at the Southern Piedmont Agric. Res. and Ext. Cntr., Blackstone, VA to evaluate TA and TFB control on fluecured tobacco with various systemic insecticides applied as soil or transplant water treatments and to determine the impact of these treatments on tobacco yield. Twelve treatments and an untreated check were established in a RCB design with 4 replications. Plots, 4 X 40 ft (1 row X 24 plants), were separated by single guard rows. Pre-transplant soil treatments of all liquid formulations except Furadan were broadcast with a CO2-pressurized tractor sprayer that delivered 32 gpa at 30 psi through 8003 LP tips on 3 May (Ambient temperature 74-76 °F, soil temperature, 70 °F; soil pH, 5.7; OM, <2%). Treatments were immediately incorporated by double disking. Band applications of Furadan and Temik were made during bed formation and immediately covered with 6 to 8 inch of soil on 8 May. Furadan 4°F band treatments were applied in a 12-inch band using a COz-pressurized backpack sprayer that delivered 16 gpa through an 8003 E tip at 30 psi. Temik was applied in a 14-inch band using a tractor mounted-Gandy granular applicator. The soil was in excellent condition for both the pre-transplant soil and bedding treatments. ‘Coker 371Gold’ fluecured tobacco was transplanted into experimental plots in a Chesterfield-Mayodan-Bourne sandy loam soil on 20 May. A measuring cup was used to apply transplant water (TPW) treatments of Orthene and Admire in 4 fl oz/plant (204 gpa) at the base of each plant in the treatment plots. Except for insect control, production practices followed Virginia Cooperative Extension recommendations. Dipel (Bacillus thuringiensis) was applied for tobacco budworm and tobacco hornworm control on 26 Jun and 8 Aug. The foliar application of Orthene were applied on 5 Jul and Aug with a CO2-pressurized backpack sprayer that delivered 28 gpa through 3 TX-12 tips at 60 psi. TA populations were estimated on the upper 4 leaves of 10 plants/plot about once a week from 5 to 9 wk after transplanting. On 25 Aug, TA damage was rated on a scale of 0 to 10: 0 = no signs of aphid damage; 10 = very severe necrosis of leaves and extensive sooty mold. TFB feeding holes were counted on 5 plants/plot at 2 and 5 wk after transplanting. Tobacco was harvested and cured and yield was determined. Data were analyzed by ANOVA and significantly different means were separated. Aphid count data were transformed to log)0 (x + 1) before analysis. Actual means are presented in the table. Admire TOW gave the best seasonlong control of TA. The Temik and Temik + Mocap GEL treatment