Corn Dry Down After Maturity

BY Dairyland Seed Agronomy Team

Many growers in the Dairyland footprint experienced higher corn moistures this year compared to recent years. The cause of these higher grain moistures varies by region, but some reasons are delayed planting, lower GDU accumulation through the growing season and wet conditions through October.

While we have seen good drying in areas recently, it is important to note that standability does not get better as the year progresses. Drying costs, and grain storability are the main concern. We have been fortunate in many locations to have seen substantial field drying, but we generally do not see much drying occur in November, so waiting for increased dry down can be for not. The following are notes about corn dry down after maturity.

Kernel drying that occurs following black layer is entirely due to evaporative moisture loss, low relative humidity and breezy conditions favor drying.

The corn drydown rate is tightly linked to daily growing degree unit (GDU) accumulation.

In general, drying corn from 30 percent down to 25 percent moisture requires about 30 GDUs per point.
Drying from 25 percent to 20 percent requires about 45 GDUs per point

GDU accumulation and drydown rates are greatest during the earlier, warmer part of the harvest season and decline as the weather gets colder.