Insect Control, 1988

‘Coker 319’ was transplanted into experimental plots 40 ft long (24 plants) and 8 ft (2 rows) wide at the Virginia Polytechnic Institute and State University Southern Piedmont Agricultural Experiment Station, Blackstone, Va., on 12 May. Treatments were set up in randomized complete block configurations with 4 replicates for 8 treatments in Test 1 and 5 treatments in Test 2. Experimental plots were separated by single untreated border rows. Insecticide treatments were applied with a CO2-powered backpack sprayer calibrated to deliver 24 gal/acre through 3 TX-10 spray nozzles/row at 60 psi. In addition to the basic treatments, Sweet and Low artificial sweetener (1.15 oz/acre) was added to separate Lannate and Orthene treatments. X-77 spreader-activator was added at 0.5 pt/acre to a third Orthene treatment. Applications were made for Test 1 on 27 Jun (ambient temperature 86-88°F) and for Test 2 on 17 Aug (ambient temperature 96-99°F). In Test 1 plants in the first row of each plot were infested with 2 second-instar tobacco hornworms/ plant; those in the second row were artificially infested with one 2-3-d-old tobacco budworm larva/plant. Hornworms and budworms were counted on all of the artificially infested plants in each row before treatment and at 3, 8, and 16 DAT. Myzus nicotianae were counted between the fourth and sixth lateral veins on the right abaxial side of 4 upper leaves of 10 plants/plot. In Test 2, field-collected budworms were used to infest 10 consecutive plants in the first row of each plot.