The traditional method for grass control in corn is based on using herbicides applied to soil and incorporated before planting or to the soil surface after planting. This approach has been successful in controlling crabgrass, fall panicum and foxtails, but johnsongrass and shattercane control was sometimes inadequate.
Witt, W. W.; Slack, Charles H.; Martin, James R.; Green, Jonathan D.; and Thompson, M. A., "Grass Control in Corn with Accent and Beacon" (1991). Agronomy Notes. 50.