Aphid Control on Connecticut Shade Tobacco with Systemic Insecticides, 1995

Abstract

Abstract Ten insecticide treatments were evaluated for tobacco aphid control in a cloth-covered shade tent at the CT Agricultural Expt. Stn. Valley Laboratory in Windsor CT. The soil was an entic haplorthod (71.8% sand, 23.0% silt, 5.2% clay, pH = 6.0 and OM = 4.0%). There were 4 replicate, 4-row plots of each treatment (15 X 15-ft), each with 2 replicate treated rows in the center and 2 adjacent untreated rows. Admire 2F (NTN33893) greenhouse-drenches were applied on 30 May to 2-month-old ‘O-40’ plants in 128-cell flats (25-cm3 mix per cell). Admire was applied at 0.12, 0.24, and 0.48 lb (AI)/acre in 1.0 ml/plant (10,800 plants/acre). On 31 May, Vydate (2.0 lb [AI] in 107 gpa) was broadcast in a 39-inch swath using a 8004E nozzle and raked to incorporate. Tobacco was transplanted on 1 Jun to rows 39-inches apart with plants 1-ft apart within rows. Vydate was also band-applied (2.0 lb [AI]/acre) on 2 Jun to 4-inches on either side of rows using a TG-3 nozzle and incorporated by hoeing. Admire was applied on 2 Jun as a soil drench, using a TG-3 at 15 psi to apply 20 ml/plant in 2, 10-ml applications 2-cm to either side of plants. Foliar Orthene or Admire was applied using a TG-3 nozzle at 15 psi on 12 Jul and 4 Aug in 204 gpa. One leaf each from 10 plants per row was removed on 24 Jul, 8 and 21 Aug (1600 leaves per date), and rated for apterous aphids (scale: 0 = no aphids or winged only; 1 = 1 aphid per leaf; and 10 = more than 1 aphid per leaf). Ratings from the 10 plants were added and treatments compared to adjacent untreated rows by the nonparametric Wilcoxon Matched Pairs Test. Treatment means within dates were compared by the nonparametric Kruskal-Wallis Test.