Tobacco Hornworm and Sucker Control on Tobacco With Tank Mixes of Dipel And Sucker Control Agents, 1979

Abstract On-farm tests were conducted in Wake and Lee counties, North Carolina, to assess the efficacy of tank mixes of Dipel WP and various sucker control agents. Plots were 0.025 acres, consisted of 4 rows separated by vacant fifth rows and 16-20 ft turn alleys, and were arranged in a randomized complete block design in 3 replicates. Two groups of treatments were tested. Group 1 treatments were tested against an artificially created homworm infestation at topping. Group 2 treatments were tested against a second artificial infestation (in different plots) 7-9 days later. Sucker control agents alone and tank mixes with Dipel were applied at 20 psi. Dipel applied separately was applied at 55 psi. All applications delivered 50 gal per acre of finished spray through three nozzles per row. Plots receiving Group 1 treatments were preceded (7-9 days) by application of the appropriate contact sucker control agent. Sixty (predominantly) second instar larvae were transferred from greenhouse tobacco to 40 plants near the center of each plot. After 2-3 days, established larvae were counted and treatments made. Three days later, surviving larvae were counted. Sucker control was evaluated on 20 plants 4-5 weeks after the final treatment. Hornworm survival was compared using the chi-square test. The effect of treatment on sucker weight, sucker number (transformed: square root of number + 0.5), yield and qualify were compared in a two-way analysis of variance using Student’s f-fest.