Currently, weed control is practiced to a very intensive level of management in the Midwest. Most all acres of com and soybean production are treated with one or more herbicides, and often with multiple applications of herbicides. And yet weed problems remain that cause concern to the grower, in some instances because of potential losses due to competition and harvest losses, and in other instances because of grower, landlord, and neighbor expectations for near perfect control of all weedy species in growing crops. Some of these greater expectations come as a result of product guarantees and respray programs, which are sometimes implemented when no significant problem really exists.