Rome Ethredge, UGA Interim Grains and Soybean Agronomist

This time of year, and with this heat, corn is moving rapidly towards maturity. The photo below shows a field of corn planted March 1st that is Denting and at Quarter Milkline, it has accumulated 2500 growing degree day units (GDUs). The top or outer quarter of the kernel is now hard and will show up darker. The maturing of the kernel will continue down the kernel until it reaches the base and then the black layer will be formed. We still need 3 weeks to reach black layer, so we still need water, especially in this intense heat.

Here’s a plan once we get to this growth stage (Quarter Milkline): Need at least 1.8 inch this week and the next, then can reduce to 1.5 inch a week when we hit 1/2 milkline, and if we are very wet and not as hot and dry at 3/4 milk you can cut off watering.


Much of Georgia corn is in the milk or dough stages as see below my graphic concerning these stages.


Our oldest corn is denting like in photo below and we still need 3.5 weeks or so from that point until black layer forms and corn is mature. Some growers will quickly harvest after black layer formation once dry so they can make early deliveries (July Contracts) and for planting Ultra late Soybeans or second crop corn.


Irrigation is critical during these hot dry days as evidenced below where an irrigation system failed where the 2 corn ears on the left were growing. Ears on the right were from a nearby pivot that kept working.