Cutworms sometimes attack corn seedlings, and flea beetles may chew holes in the leaves of young plants.
Corn earworms are one of the best-known corn pests. They also attack tomatoes and are most prevalent in the southern and central states. Earworm moths lay eggs on corn silks, and the larvae crawl inside the husks to feed at the tips of the developing ears. The yellow-headed worms grow up to about 2 inches long and have yellow, green, or brown stripes on their bodies. To prevent earworm problems, use an eyedropper or spray bottle to apply a mixture of vegetable oil, Bt (Bacillus thuringiensis), water, and a few drops of dishwashing liquid to the tip of each ear several days after the silks emerge. Or you can try pinning a clothespin to the tip of each ear once the silks start to turn brown to prevent the worms from crawling through to the ear.
European corn borers are 1-inch-long, flesh-colored worms marked with tiny black dots that feed on foliage, especially near the top of the stalk where the leaves emerge. They also bore into the developing ears. Bt and spinosad are effective controls if applied early, before the borers tunnel into the stalks. Corn borers overwinter as full-grown larvae in weed stems and old cornstalks. Pull up and destroy such winter refuges to break their life cycle.
Hand Pollinating Corn
In order to produce kernels, wind must deposit pollen from the tassels (plant tops) onto each of the silks on the ears. Every unpollinated silk results in an undeveloped kernel. If you’re planting only a single or double row of corn plants, you can improve pollination by transferring pollen from tassels to silks yourself. Collect pollen as soon as the silks emerge from the ears and the tassels have a loose, open appearance. Wait for a morning when there’s no breeze, and shake the tassels over a dry bucket or other container to release the pollen. Collect pollen from several plants. Immediately transfer the pollen into a small paper bag and sprinkle the powdery material onto the silks of each ear in your corn patch. Repeat once or twice on subsequent days for best results.
Cucumber beetle larvae, also known as corn rootworms, feed on corn roots, causing plants to weaken and collapse. Adults are yellow beetles with black stripes or spots. To kill the rootworms, apply Heterorhabditis nematodes
to the soil.
Seed-corn maggots attack kernels planted too deeply in cool soil. These yellowish white maggots are ¼ inch long, with pointed heads. If they attack, wait until warmer weather to plant another crop at a shallower level.
Animal pests can seriously reduce your corn yields. Birds may be a problem at both seeding and harvesting time, while raccoons are fond of the ripening ears. For information on discouraging these creatures, see the Animal Pests
Clean garden practices, crop rotation, and planting resistant hybrids are the best defenses against most diseases, including Stewart’s wilt, a bacterial disease that causes wilting and pale streaks on leaves.
makes pale, shining, swollen galls that burst and release powdery black spores. Cut off and dispose of galls before they open. If necessary, destroy affected plants to keep smut from spreading. It can remain viable in the soil for 5 to 7 years.
Harvesting: Three weeks after corn silks appear, start checking ears for peak ripeness. Pull back part of the husk and pierce a kernel with your thumbnail. If a milky liquid spurts out, the ears are at prime ripeness—rush those ears to the table, refrigerator, or freezer. Ears on the same stalk usually ripen a few days apart. A completely dry silk or a yellow or faded-green sheath means the ear is past its prime.
Leave ornamental corn and popcorn on the stalks to dry until the first hard frost. If the weather is cloudy and wet, cut and stack stalks in a cool, dry place until the corn dries.
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