WICHE: Small ears may mean poor pollination for corn

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The corn is looking good in some areas of my county and not so in others.

By Jeneen Wiche

I gave up growing corn a long time ago. I figured others can grow it better than I, so why take up the space. I drive by Gallrein Farms in Bagdad twice a week, and their “sweet corn” sign has been hung, so there are no worries. They have the best corn this side of the Mississippi.

The corn is looking good in some areas of my county and not so in others. The 100-degree heat certainly did not help with good pollination and ear development, but there are other things that can cause small stalks, small ears, poor kernel development and other corn ailments…does this sound like your corn crop this year?

Several factors may be at work depending on where you live and the amount of rainfall you have received:

  • Drought at the wrong time can stunt your corn crop.
  • Cold damage can stunt corn (if you put your crop out early you could see a little stunting from a late spring cold snap).
  • Poor drainage and poor soil fertility, especially nitrogen, can stunt the crop as well.

Corn needs what most other summer crops need: good soil and drainage, adequate nutrients and temperatures above 60 degrees for germination and growth. Corn is actually a heavy feeder, so healthy soil with some side dressing is a good idea to maximize the quality of harvest.

Add composted manure when preparing the planting block and then follow up with a balanced fertilizer or additional compost every two weeks or so thereafter.

Water needs are not excessive, but irrigation (if it doesn’t come naturally) when the stalks begin to flower will promote larger ear development. The rest relies on cross-pollination.

Corn flowers and begins to shed its pollen several days before the silks actually emerge. The pollen shed continues for about a week, during which most of the action takes place in late morning.

It is rare for the pollen of the same plant to actually fertilize itself; it usually floats to other plants, travels down the tube of the silk where it finally reaches the female flower.

Sweet corn for eating is one of those crops best grown en masse in the field. Good cross-pollination, often facilitated by a breeze, needs to occur between different corn plants; each silk that comes from the top corresponds directly to a kernel inside. If the silk isn’t pollinated, then the corresponding kernel does not develop…pretty darn cool, really.

The problem with backyard garden corn is that people often just plant a few rows out which usually results in poor pollination because when the breeze hits it just blows the pollen over the single neighboring row, and it pollinates nothing. In order to improve cross-pollination and ensure a full ear of corn, plant large blocks of corn instead of a few long rows.

The most common pest of corn is the corn earworm (and maybe a hungry bunch of raccoons). The adult moth of the earworm lays her eggs on the silks of corn. Once the eggs hatch, they begin feeding on the silks, working their way down into the husk where the real prize awaits, the developing kernels of corn.

Commercial growers often use insecticides, but for the home gardener, this is not necessary because there is generally only one earworm per ear (they eat each other if there is more than one). The corn is still edible. Simply cut off the end that has been eaten by the corn earworm.

One organic approach to deterring corn earworms is dropping a small amount of vegetable oil in the middle of the silks as they begin to form. I’ve not tried it, but it is worth a shot of you have the problem.

Corn is ready to harvest when the silks dry and turn brown to black in color. Peel the husk back a little and pierce a kernel with your fingernail. If a milky juice squirts out, you are ready to go.

Sweet corn undoubtedly has high sugar content, but it is best if it is eaten within 12 hours of harvest because as soon as it is picked the sugar in the corn begins to slowly turn to starch.

If you are not ready to eat your harvest, keep it cool in the refrigerator or process it for freezing or canning.

Many of the newer hybrids stay sweeter longer, however.