When corn planting was delayed until the last of May in many areas, and even early June in other areas, one big fear was that it would mean wet corn this fall. Many who bought dryers or beefed up their drying and storage system after the wet 2009 crop didn't get to put it to the test since last fall was unusually dry and it was an incredibly early harvest. However, after planting so late, many figured this was the year when they would test out new dryers.
They may still need dryers in some cases, but Bob Nielsen, Purdue University corn specialist, doesn't believe corn will be as wet as many people expected when it comes out of the field. He's looking at a sizable portion of the crop reaching black layer by mid-September, and perhaps nearly all of it reaching black layer by the end of September.
Once corn reaches black layer, it's no longer in danger from a frost. What is in the kernel is there to stay, and nothing more is going in. Moisture level at black layer can vary from 25 to 40%, but typically averages around 30%. The kernels will lose moisture and dry down, but they won't lose starch after black layer forms.
Frost damages corn by killing leaves and. or the stalk, and preventing the plant from making more sugars to convert into starch and place in the kernels. But if the kernels are already mature anyway, then a frost won't matter.
What's caused the fast progress of the crop is the excessive heat, he says. Corn planted late typically needs about 200 less growing degree days to reach maturity anyway. And the excess heat has shoved it along. By the first of August, corn that started three weeks behind was only one week behind.
There may also be less corn to dry. Nielsen is concerned that the excessive heat may have interfered with pollination, especially in areas where corn went in later. If nothing else, fields he's checked so far indicate considerable abortion of kernels. Some tip abortion is normal. But if there is more than an inch of cob without kernels, then normally something caused the plant to change its mind and decided it couldn't fill those last kernels at the tip of the ear. Kernels form and fill from the butt end of the ear toward the tip.That signal may have been excessive heat and dry weather.