Field Corn, Corn Rootworm Larval Control, 1983

Soil insecticides to control larvae of the corn rootworm were evaluated at two locations in northeast Nebraska. Corn was planted on 9 and 13 May, Belden and Royal respectively. The Belden plots were nonirrigated and the Royal plots were irrigated with an overhead center pivot irrigation system. All treatments were applied in a 7-in. band over the row (1.2 oz (AD/1,000 ft row). Planting time treatments were incorporated with a six-prong harrow mounted on rear of applicator. Cultivation treatments were incorporated immediately by a tractor mounted cultivator. Each treatment consisted of one row 75 ft long replicated four times. Insecticide treatments were evaluated for root damage in late July by digging five equally spaced plants from each row (20 plants total per treatment) and rating the roots for rootworm feeding damage using a 1 to 6 damage scale (1, no damage; 6, three or more nodes of roots destroyed).