(F117) TOBACCO: Nicotiana tabacum L., Burley 'TN 90' FLEA BEETLE AND APHID CONTROL ON BURLEY TOBACCO, 2001 Paul J. Semtner Virginia Tech Southern Piedmont Agricultural Research and Extension Center 2375 Darvills Road Blackstone, VA 23824 Phone: (434) 292-5331 Fax: (434) 292-5623 E-mail:
[email protected] Lee Wright Southwest Virginia Agriculture Research and Extension Center 12326 VPI Farm Road Glade Spring, VA 24340 Tobacco flea beetle (TFB): Epitrix hirtipennis (Melsheimer) Green peach aphid (GPA): Myzus persicae (Sulzer) This trial was conducted at the Virginia Tech Southwest Virginia Agricultural Research and Extension Center, Glade Spring, VA, to evaluate various insecticides applied as transplant drench (TD) and transplant water (TW) treatments for control of TFB and GPA on burley tobacco. Tobacco 'Tennessee 90' was transplanted into experimental plots on 21 May. Normal production practices were followed for fertilization, weed and disease control, and topping and sucker control. Eleven treatments and an untreated check were established in a RCB design with four replications (Table 1). Plots were 8 by 30 ft (2 rows by 15 plants). A CO 2 -pressurized backpack sprayer with an 8003E tip and operated at 20 psi was used to apply Admire and Platinum TD treatments in 17 fl oz of water to plants in 288-cell float trays on 16 May 5 d before transplanting. Additional water was used to wash the chemical residue off the plants and into the media. Immediately after transplanting, a measuring cup was used to apply the TW treatments in 4 fl oz (170 gpa) to the base of each plant in the designated plots. The growing season was mild with adequate rainfall. TFB and TFB feeding holes were counted on 10 plants/plot weekly for 4 wk after transplanting. GPA numbers were rated on a scale of 0 to 7 where 0 = 0 GPA, 1 = 1 to5 GPA, 2 = 6 to 25 GPA, 3 = 26 to 100 GPA, 4 = 101 to 250 GPA, 5 = 251 to 1,000 GPA, 6 = 1,001 to 5,000 GPA, and 7 = > 5,000 GPA. GPA ratings were made weekly from 13 Jul to 3 Aug. Data were analyzed by ANOVA and significantly different means for insect data separated by Waller Duncan k-ratio t-test (k-ratio=100). TFB feeding data were transformed to Log10(x+1) before analysis. Actual means are presented in the tables. TD applications of Admire and Platinum were the most effective treatments giving very good to excellent control of the TFB and reduced TFB feeding holes on each of the four observation dates (Table 1). Admire applied as TD treatments was generally more effective than TD applications of Platinum. The TW applications of Admire, TM-44401, and Platinum were generally less effective than the TD treatments with Admire and Platinum (Table 1). Of the TW treatments, Platinum was most effective for control of TFB and TFB feeding damage, TM-44401 was intermediate, and Admire was least effective (Table 1). The Orthene TPW was the least effective treatment, giving fair to good control of TFB and TFB feeding damage through 18 Jun (Table 1). All treatments reduced GPA ratings from 13 Jul (53 days after transplanting) to 3 Aug (75 days after transplanting) (Table 2). GPA control was best with the Admire and Platinum treatments. Platinum was slightly more effective than Admire at similar rates and the same application methods (Table 2). The high rate of TM-44401 gave control similar to the low rate of Admire applied in the TW (Table 2). TM-44401 TW treatments were less effective than the Platinum TW treatments (Table 2). The Orthene TW treatment and the low rate of TM-44401 were the least effective treatments for GPA (Table 2).
