Corn1. Q. Should garden corn be planted in several short rows rather than in one or two long rows?
A. Yes. Corn is pollinated by wind-borne pollen. Planting corn in blocks rather than in long rows makes it easier for the plants to pollinate one another during tasseling.
2. Q. Should the suckers, or side shoots, which emerge near the ground level on sweet corn be removed?
A. This is not necessary although experienced gardeners feel removal of the suckers will result in larger, high-quality ears. The suckers should be snapped off while they are small.
3. Q. How long does it take for most sweet corn varieties to produce edible ears?
A. Most sweet corn varieties on the market today will mature between 60 to 90 days after seeding. Maturity rate will vary greatly from year to year and from season to season depending on temperatures.
4. Q. Why are ears of corn underdeveloped at the tip end?
A. This is common not only in gardens, but also in large commercial planting. Several explanations have been suggested as the cause including nutrient deficiency, loss of foliage because of disease with correspondingly lower food manufacturing capacity, cool temperatures during ear maturity and low moisture. Corn is cross-pollinated by wind-blown pollen from the male flowers or tassels at the top of the plant to the female flowers or silks about midway up the stalks. Each kernel develops from an individually pollinated silk. Kernels develop near the middle and base of the ear first with those at the tip developing last. When unfavorable conditions occur such as those mentioned above, those kernels pollinated first will take precedence over those pollinated last. This often results in failure of the kernels near the tip to develop properly.
5. Q. How come some years sweet corn is sweet and tasty and other years it lacks the desired flavor?
A. The flavor of sweet corn is highly dependent on weather conditions. If it rains within a week of harvest time, the flavor of sweet corn is often greatly diminished. Also, if the corn matures during high daytime temperatures as well as high nighttime temperatures, the sugar levels of sweet corn will be low and flavor will be disappointing. The sugar in sweet corn is converted to starch rapidly even under optimum storage conditions so the corn should be cooked soon after harvest.
6. Q. Is there a best time of day to harvest sweet corn?
A. Experienced sweet corn gardeners recommend harvesting corn during the early morning. This insures the sugar will be at its highest level if the corn is mature, but not overripe.
7. Q. How often should sweet corn be fertilized to produce high yields of good quality corn?
A. Sweet corn should be lightly fertilized prior to planting. It should be fertilized again when the plants are approximately 4 inches tall and when they are 8 to 10 inches tall. Approximately 1/4 pound of complete fertilizer for every 10 feet of garden row is sufficient in most areas of Texas.
8. Q. This year my sweet corn produced yellow and white kernels on the same cob. What's wrong?
A. This could be the result of a bicolored variety or perhaps cross-pollination. Some new varieties, primarily those with an extra sweet character, produce white and yellow kernels on the same cob. The bicolored varieties include "Sweet-G 90" and "Honey and Cream." These new hybrids are produced by crossing white and yellow inbreds. However, if you planted yellow and white sweet corn in your garden or a neighbor planted a different type sweet corn, multi-colored kernels on the same cob could result.
9. Q. What is meant by advertisements in catalogs referring to "Super Sweet" varieties of sweet corn?
A. Newly-developed "Super Sweet" hybrid varieties may contain up to 40 percent more sugar than some of the standard varieties. Super sweet hybrids carry a genetic factor which results in a high sugar content. The super sweet character is lost if the corn is pollinated by ordinary sweet corn or field corn, so the super sweet hybrids should be planted away from any other type of corn.
10. Q. What is the difference between roasting ears and sweet corn?
A. To most, roasting ears are field corn harvested at an immature stage. Some people prefer field corn because the ears are larger and the corn is not as chewy. There is no comparison in flavor between sweet corn and roasting ears if the sweet corn is grown under proper conditions, harvested at the right stage of maturity and handled properly between harvest time and cooking time. Corn was originally "roasted" in the fire coals.
11. Q. My sweet corn produced normally. However, as the ear formed, the tip of it became covered with a white mass that grew until it broke open and exposed a black, powdery mass.
A. This is corn ear smut. It is a fungus and is carried in the seed. To avoid this, use only high-quality seed from a reputable source. There is no chemical control for this disease.
12. Q. The foliage on my sweet corn is developing red lesions.
A. This is rust. There is no chemical control. Some varieties of corn are less susceptible than others. It does little damage under normal conditions. However, an infection which occurs early and continues to develop, can cause losses.
13. Q. My sweet corn grew for a while and then had a mosaic appearance. The corn did not develop properly. The ears that formed were poorly filled.
A. This is maize dwarf mosaic virus. This virus commonly occurs on sweet corn in Texas. It overwinters in johnson grass around a garden. To control the problem, remove the johnson grass and follow a good insect control program. Also, some varieties of corn are more resistant to this disease than others.
14. Q. I planted corn in my garden this fall and it turned out beautifully, but the worms ate more corn than my family. What can I do to prevent this?
A. Spray or dust the ear silks with Sevin (carbaryl) to prevent adult insects from entering and laying eggs. Begin dusting and spraying at an early stage and repeat every two days. Some gardeners apply a drop of mineral oil or use a Bt insecticide on the silks to prevent earworm damage.
15. Q. Are there any earworm resistant varieties of sweet corn available?
A. No. Some varieties seem to be bothered less by corn earworms than others, however, none are truly resistant. In general, the higher quality and sweet corn is more likely to be bothered by earworms. Varieties of sweet corn which have a tight shuck near the silk end seem to be bothered less by earworms than those that have loose and open ends.
16. Q. The center of my corn plants are stuffed with little green insects. What do I do about them?
A. Corn leaf aphids infect the swirl of young corn plants. The plants will tolerate large numbers of these aphids. If plants begin to wilt or die, spray them with an insecticide or insecticidal soap. Use as directed on the label.
18. Q. I want to buy and freeze some sweet corn. How should I prepare it?
A. Corn is easy to freeze. The Texas A&M Extension home economists say to shuck and blanch (cook in boiling water or steam) corn for 7-10 minutes, immediately cooling in ice water, before freezing. However, some of the old timers say throw it in the freezer shuck, silk and all after putting ears into a freezer bag. They microwave it in the same container, in the shuck, then shuck and silk it immediately before eating. Such a procedure prevents freezer burn and, supposedly keeps the corn garden fresh.
19. Q. Could sex be the answer to worm-free corn?
A. You bet. You corn-eating worms had better watch your sexual habits; they could lead to your demise!
ARS scientists are working on a new technology which they hope will allow growers to control Helicoverpa zea (the corn earworm, tomato fruitworm and cotton bollworm) with fewer chemicals than currently used. The scientists are hoping to capitalize on a peculiar habit of the adult female H. zea: she feeds the first night after she emerges and postpones mating until the second night. If what it is that attracts the moths to certain flowers can be determined, then perhaps the food can be laced with pesticides and thus kill the females before they have a chance to mate.
So now the trick is to reproduce the plant's flower scents artificially. Scientists have identified about a dozen major compounds within the floral extracts--all of them easily synthesized. But the question still remains: which of those dozen compounds is the one or ones that actually attracts the moths? Since there are thousands of possible mixtures, it may take a year or longer to discover the ideal combination. Once that has been done, the floral attractant, a feeding stimulant, and an insecticide could be impregnated in a twist tie which could be wrapped around the cornstalk or tomato vine.
The twist tie, unlike sprayed insecticides, need never touch the ear of corn or the tomato. Yet, the insecticide would be much more effective than trying to kill caterpillars burrowed deep into a plant. Since each female is capable of laying 500 eggs, killing the females before mating would require less expensive chemicals. Finally, since moths can travel 300 miles or more in a single night, this method will stop them before they have a chance to travel, spreading crop damage.
20. Q: Is there a study that shows the maximum dispersal distance for corn pollen? I'm a palynologist and the only thing I find in our literature is that corn pollen is heavy and doesn't travel very far. One reference gives a maximum distance of 500 meters. Surely, farmers need this information in order to grow seed corn when they have to isolate the female parent from unwanted pollen.
A: All farmers and gardeners have to know is to plant at least 3 rows side-by-side (rows 36 inches apart) or in a circle to insure good pollination. If cross pollination is required in hybridization, similar varieties are planted in the same block and/or the female plants are sterilized by removing the tassels. I am not familar with the ultimate distance a pollen grain can be transported. Of course it would depend on wind velocity.
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