Northeast Research and Demonstration Farm
Corn planting date studies have been included at this site since 1976. The exact dates changed periodically as the objectives of the test changed and due to adverse environmental conditions at planting time in some years. More detailed accounts of earlier tests and long-term summaries can be found in prior reports. This report compares 1997 through 2003 results with long-term averages.
Iowa State University
Pecinovsky, Kenneth T. and Benson, Garren O., "Corn Planting Dates" (2004). Iowa State Research Farm Progress Reports. 1375.