Labeled rates of corn rootworm insecticides have been tested in conventional-till (chisel plowed then field cultivated) fields over the past six years. For the past three years, these same insecticides have been examined in no-till fields. In all tests, insecticides went head-to-head in their ability to protect corn roots from corn rootworm larval injury. Roots from untreated check rows, in both tillages, averaged about 1.5 nodes (circles) of roots destroyed. Any tests that did not challenge an insecticide's performance (no obvious root pruning in the untreated rows) were not included in the analysis.
Iowa State University
Oleson, James D. and Tollefson, Jon J., "Corn rootworm insecticide consistency" (1998). Integrated Crop Management News. 2259.