Don't Hire Me To Estimate Corn Yields!

Drastic miscalculation due to where corn was in development process.

Published on: Nov 15, 2012

The first time I checked a cornfield for a neighbor this summer, I had a sinking feeling that it was going to be a total disaster. Pollination was still underway, but ears were small, and it wasn't clear how much pollination was going to occur. About a third of the field consisted of blacker soils, and that area looked better. Still, I walked out of that field after doing a few rough estimates thinking 20 bushels per acre might be about it. The overall field is not a very producitve field, and farmers were talking about 40 bushels per acre for the county average in Johnson County at the time.

After rains came in August and temperatures moderated somewhat, I visited the field again in mid-September. Some of those plants with small ears that I wasn't sure if they would pollinate or not went ahead and pollinated. The acid test was driving back to the Miami hill on one side of the field. Ears were small, but there were ears. That couldn't be said for every field this year.

Ears Developed: Missing the worst heat for peak pollination helped corn make a decent, even if sub-par, yield.
Ears Developed: Missing the worst heat for peak pollination helped corn make a decent, even if sub-par, yield.

Doing a few more rough counts, I thought maybe my first estimate had been made in haste. Pollination was going to be better than I thought. I went back and told the owner that perhaps the field would make 40 bushels per acre.

When he harvested it within the last week he decided I wasn't very good at guessing yields. The field made just over 80 bushels of dry corn per acre. It's not exactly a bin buster – about 60% of what this field is capable of producing, but it will likely be above county average on less than average soil. For this year in many parts of Indiana, 80 bushels per acre is a respectable yield.

How was I so far off? Because ears that I wasn't sure if they would pollinate or not went ahead and pollinated. The secret was that this field was planted in mid-May, not late, but not as early as most other corn. When the peak heat hit, it was just thinking about pollinating. It was still dry when it pollinated, but not nearly as hot.

This was a good year, in retrospect, to plant a bit later than super early. File that thought away. It might be the right strategy in another 75 years!