Wireworm Control on Sweet Potatoes, 1975

Telone at 15 gal per acre was applied broadcast for nematodes two weeks prior to planting. Sweet potatoes 'Georgia Red' were planted on June 3, 1975. Preplant treatments were applied just prior to planting. Foliar treatments were applied at lay by on July 29, 1975, when roots were enlarging. Plots consisted of single 50 ft rows with four replications in randomized complete blocks. Soil was classified as Norfolk Sandy Loam with adequate soil moisture. Granular insecticides were applied in a 2 ft band with a hand shaker jar. Liquid insecticides were applied with a watering can at 1 gal water per 50 ft row. Potatoes were harvested on October 9. Wireworm damage was evaluated by scoring 25 roots selected at random from each row in each replicate. Damage classes were: 0 = no damage; 1 = up to 5 holes; 2 = 6 to 10 holes; 3 = 11 or more holes/sweet potato. When this damage was averaged, a “damage index” was obtained. “Percent damage control” was arrived at by the following formula: for treated sweet potatoes let A = the damage index and B = the % sweet potatoes damaged; for untreated (check) sweet potatoes let X = the damage index and Y = the % sweet potatoes damaged; then 100 - (AB/XY × 100) = percent damage control, a factor which reflects the effectiveness of the insecticide by comparing wireworm damage to potatoes from treated plots with potatoes from untreated plots.