If you're going to submit your guess on final yield for this field later in the season, don't be alarmed by this simple corn field mystery. It took 10 minutes of walking to find this spot, and it only covers a small section of one row. Most of the field is picture perfect.

Crop Watch 6/18: Growing point moves above ground in Crop Watch '15 field

Check below to see how you can win free seed later this year by guessing the yield of this field.

Crop Watch 2015: Problem spots are few and far between in this corn field.

Every field has a blemish somewhere. Right now it's hard to find any in this field. We found the one pictured. The stand is thin for maybe 75 feet. In this photo you can see a few shorter plants. The shadows of leaves from the adjoining row indicate the height and health of the rest of the field.

So what happened here? Look at the giant wheel track. This row fell right in the wheel track. The field was planted with a central-fill planter. Is it possible that soil compaction in this one spot was an issue?

We dug up the plant. The root system was small, but roots were correctly shaped. There were no signs of disease or insect feeding on the plant.

The second clue is there if you look closely at the leaves. One leaf is brown and a bit ragged, hanging off to the side. Nitrogen was sidedressed on the field. Is it possible that this plant or a few plants here were damaged by nitrogen? Perhaps, for whatever reason, injection and sealing wasn't perfect here.

Crop Watch 6/12: Count the ways you could lose precious nitrogen

Blip on the radar screen: Something went wrong in this tiny spot. Look for clues as to what might have happened.

Truth is, we don't know the answer. From what Bill Johnson, a Purdue University Extension weed specialist, says, it's likely more than one thing. He says that often when asked to look at potential herbicide injury. Johnson says he's never been in a field where the only cause was herbicide injury.

The field overall has excellent yield potential.

Send your guess of final dry yield per acre to us at P.O. Box 247, Franklin, IN 46131, or email [email protected]. If you're the closest you win eight bags of Seed Consultants seed corn for 2016. If you place second you get six bags. And if you place third, you still get four bags.

Entries are due Sept. 15. Entries are limited to residents of Ohio, Indiana and Michigan.