Western Corn Rootworm and European Corn Borer Control, 1986

Experiments were conducted at 2 sites in Clay County, Neb. The Experiment 1 site has been in corn since 1972; the Experiment 2 site was a trap crop of mixed-maturity corn and pumpkins in 1985. Each experiment was a split-plot design, with insecticide as the main plot and subplots (1 row) were method of application. There were 4 replications in each experiment. Rows were spaced by 30 inches and were 37 ft long. Application was made by applying granules from a V-belt seeder into the granule delivery tube mounted on the planter. Granules were directed just in front of the press wheel through a 7-inch bander. Foliar applications were made by applying granules over the plants from a V-belt seeder mounted on a cultivator. Corn rootworm damage was measured by digging 5 plants/plot (20 total) 14—18 Jul (early tassel stage), washing the soil from the roots, and rating each root on a 1-6 (Iowa) scale. The same plants were dissected and the percentage of plants infested and number of cavities caused by European corn borers were recorded.