Control with Systemic Insecticides, 1988

The experiment was established in a tobacco field at the Southern Piedmont Agricultural Experiment Station, Blackstone, Va. A Wedowee sandy loam soil (pH 5.8; <2% organic matter) was plowed on 17 Feb. Experimental plots consisted of 2 tobacco rows 40 ft long (24) on 4-ft centers. Adjacent plots were separated by single untreated border rows, and 5-ft vacant alleys separated blocks. Treatments were arranged in a randomized complete block design with 4 replicates. Broadcast treatments were applied and incorporated by disking on 10 May. Liquid treatments were broadcast with a CO2-powered backpack sprayer that delivered 25 gal/acre at 30 psi through 8003 spray tips spaced 20 inches apart. Granular DiSyston and Furadan were broadcast with a Gandy mounted on a pushcart. The soil was in good working order and the air temperature was 80-83°F. Temik treatments were applied on 12 May in 12-inch bands in front of the bedder using the pushcart-mounted Gandy. ‘VA 309’ tobacco was transplanted with a mechanical transplanter on 16 May. The Orthene transplant water treatment was applied at 200 gal/acre (4 fl oz/plant). Rainfall totals were 1.4, 2.75, 4.25, and 1.8 inches in May, June, July, and August, respectively. The test was irrigated with 1.5, 1.0, and 1.0 inches on 6 Jul, 12 Jul, and 20 Jul, respectively. Myzus nicotianae were counted between the fourth and sixth veins on the right half of the underside of 4 upper leaves of 10 plants/plot at approximately 7-d intervals from late May through mid-July.