Corn Planting Date and Potential Yield
April 30, 2009
The best chance of high corn yields correlates to early planting dates. But what is considered early? Generally speaking, anytime between the last week in April and the middle of May is a good time for planting corn and considered early.
Supporting data comes from South Dakota State University and North Dakota State University. Research for 101-103 day corn at SDSU Southeast Experiment Farm over 14 years showed yields in the 130-132 bu/ac range when planted April 17th through May 17th respectively at Beresford, SD. Research conducted by NDSU at Fargo, ND showed corn planted May 1st yielded 104.1 bu/ac while corn planted May 16th yielded 116.8 bu/ac, averaged across 21 corn hybrids. The average yields of 15 hybrids at Lisbon, ND followed that same trend—no yield loss through mid-May planting.
The University of Minnesota indicates a more linear relationship to planting date and yield with 2-3% loss every 5 days through the month of May. Considering the U of M sliding scale, the expected yield loss at May 15th is 9%. This estimate differs from the data found in ND and SD research. Although it’s less than ideal, it is most likely worth it to stick to your original plan. One thing is for certain… there are no easy answers.
Moving even later on the calendar, corn yields drop significantly as planting dates move to the end of May and into June. Corn yields at the NDSU research trial in Fargo, ND were reduced to 86.5 bu/ac when planted June 3rd. The University of Minnesota project yield losses jump to 17-23% for May 30 and June 4, respectively.