Sweet Potato Weevil Control, 1976

Six inch stem cuttings of Nancy Hall variety sweet potatoes were dipped in insecticide solutions (Table 1) and allowed to dry. The cuttings were then placed in cylindrical screened cages (height = 17 cm, diameter = 8.5 cm) and maintained with the lower 1 in. in a small jar of water. These cages were kept in a greenhouse. Each treatment was replicated 5 times and arranged in a completely random design. Ten field collected sweet potato weevils were introduced into each cage at the following post-drying times: 1, 7, 14, 2 1 , 28, and 35 d. The numbers of dead weevils were recorded 4 days after introduction. Sweet potatoes (Purple Stem) for the field trial were planted 1 ft apart on Aug 26, 1975 in Rockdale soil. Plots were single rows on 8 ft centers, 25 ft long with 4 replications in randomized complete blocks. Treatments (Table 2) were applied every 3 weeks with a tractor mounted sprayer with 5 nozzles per row which delivered 100 gal wafer per acre with 250 psi pressure. A tofal of 9 applications were made. The plots were harvested Mar 26, 1976. Six pounds of potatoes (3 two lb samples) were collected from each plot and held in paper bags in the laboratory (approximately 75° F). The bags were inspected periodically and the number of weevils emerging over a 28 day period recorded.