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When is corn a weed, and when is it corn?

When is corn a weed, and when is it corn?
Crop Watch: Four examples illustrate when corn is actually a weed!

The Crop Watch ’16 field was planted April 27. Where it’s located, that didn’t turn out to be the best day to plant corn this year. More than two weeks of cool, wet weather followed. Instead of replanting, the farmers elected to spot in corn in the worst parts of the field.

It appears they made the right choice. But they also created situations that will be interesting to follow where young corn and older corn mix. Stay tuned.

CORN OR WEEDS? The whole field is corn, but some of these corn plants will actually act like weeds later in the season.

“Right now we’re evaluating which plants will contribute to yield from the second planting, and which ones will likely hurt yield,” says Dave Nanda, a crops consultant for Seed Consultants Inc., sponsor of Crop Watch ’16. “If a plant, even a corn plant, will use nutrients and resources and deliver little or no yield, it’s a weed. If it has enough room and the opportunity to produce grain, then it’s corn, not a weed.”

The four examples pictured here make Nanda’s point.

1. Too much competition for these small plants.

Spotting in corn may be more of an art than a science. In this case, there is a good population of both plantings. The smaller corn is so much shorter and so far behind that it will likely get shaded out and not produce corn. By Nanda’s definition, that makes those plants weeds for all practical purposes.

When is corn a weed, and when is it corn?

SMALL PLANTS BECOME WEEDS: Smaller plants next to larger plants are barely visible. Parts of this field were spotted in where the original stand was weak.

2. Split rows should produce corn.

Even though there is a good stand of both plantings here, the rows are spaced nearly equally apart. That should give the younger plants enough elbow room to get sunlight and produce corn. If they produce enough grain to contribute to yield, they’re not weeds, Nanda says.

When is corn a weed, and when is it corn?

PLANTS WITH A CHANCE: Note the smaller plants growing between two rows on the left. Dave Nanda says these plants aren’t weeds because they have a chance to contribute yield.

3. Big brother will take over.

If you’re a corn plant, it’s not always good to have a big brother. In the poor part of the field with gaps between plants, some plants will be weeds and some won’t. Here’s a weed.

When is corn a weed, and when is it corn?

TOO MUCH SHADE: The small corn plant right next to the larger plant from the first planting will likely act like a weed because there is too much competition for light, Dave Nanda says.

4. These are yield contributors. 

There is enough of a gap between tall plants here that the younger plants — all but the ones directly next to an existing tall plant — will likely act as corn and not weeds. They should enhance yield.

When is corn a weed, and when is it corn?

CHANCE TO CONTRIBUTE: These plants from the second planting with no nearby neighbors should produce ears and contribute to yield.

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