Use growing degree days, not calendar days, when planting cornMay 2, 2014
“Think of corn in thermal time (growing degree days) instead of calendar time,” advises Emerson Nafziger, University of Illinois agronomist. “If the whole (corn) crop got planted May 10 instead of May 1, we would not see a big drop in yield. We won’t lose a huge amount of yield until mid-May. We may have forgotten there’s a real advantage for the corn plant to be in a fairly warm soil, ready to germinate and emerge in five to six days."