Tobacco Aphid Control, Ontario, Canada, 1988

Abstract

Abstract Experimental plots were established in a field at the Research Station, Agriculture Canada, Delhi, Ontario. Tobacco was transplanted into the field on 27 May. The experimental plots were arranged in a split plot design with 2 main plots and 3 replications. There were 6 treatments, consisting of 3 insecticides at 2 rates, and an untreated check in each main plot. Individual subplots were 76 × 14 ft and consisted of 4 rows of 38 plants in each row, the outside rows in each subplot being guard rows. Sprays were applied with a power sprayer using 3 nozzles/row: TG3-TG5-TG3 that delivered 40 gal of liquid/acre at a pressure of 15 psi and 2.5 mph speed, and TG2-TB3-TG2 nozzles that delivered 20 gal of liquid/acre at 10 psi and 3.0 mph speed. All treatments were applied evenly on full-grown, topped tobacco plants over each row in each subplot on 8 Jul. To assess aphid control, 3 leaves were collected at random from each subplot 1 d before treatment and at different dates after treatment. The number of living aphids on the leaves was counted by taking the leaves to the laboratory and examining them under a Luxo lamp magnifier. The aphid counts were transformed into logarithmic scales before ANOVA. Duncan’s multiple range test was used to separate treatment means. Means were converted to original units for presentation in the table.