The cold end of April weather has farmers worried about the uneven emergence of their corn crop. University of Illinois agronomist Emerson Nafziger says they shouldn’t. The trick is not to think of the emergence difference in terms of days, but rather in growing degree days or heat units.
Nafziger; “If you look forward and you say it takes, rather, if you get 5 growing degrees a day and it takes three days to come up, that’s 15 growing degree days. In June, 15 growing degree days is part of one day. And so, those plants are going to catch up for sure by the time it gets warm.”
That is to say if some corn is up today and it takes another three days this week – with highs in the 60s – that’s just 15 growing degree days or in June only part of one day. The later emerged corn will catch up says the Illinois agronomist.