Maybe it was because corn was further along than some thought when the dry weather in August hit or maybe it was because the ears had already formed fairly large kernels – either way, Danny Greene of Greene Crop Consulting, Inc., Franklin, Ind., found some evidence of stalk weakness in fields he checked before harvest.
In some cases ears would be filled out but the stalk failed the push test. It didn't bounce or spring back when he pushed on it. Sometimes several stalks within a section of row didn't spring back. That usually indicated lodging potential. The culprit is typically stalk rot.
In this case, Greene didn't find evidence of stalk rot. The pith was clean and white when he cut into stalks, and he didn't find black specks on the outside that might indicate the presence of Anthracnose stalk rot. Instead, his theory is that the plants decided to take nutrients from the stalk and divert them to the ear to finish filling kernels that were already filling when the dry weather hit.
On lighter soils, he found a few chaffy ears. But in most parts of most fields he found ears of good test weight. When broken in half, the kernels appeared deep. When examined, individual kernels were well-filled and reasonably deep. That's not what you would normally expect to find six weeks after a dry spell began.
Yields that rolled out in fields where Greene had looked earlier seemed to bear out his theory. Some of these fields needed to be harvested early so they wouldn't lodge and lead to high mechanical loss, but not because of stalk rot. The plants simply gave up all they had to make sure that the ears and kernels each ear were as plump as possible.