By Dr. Harold Willis
If you want to try growing open-pollinated corn, be prepared to go to some extra trouble and care. High quality often takes more work, but it is worth it. After you find an open pollinated variety you like, you can then grow your own seed and improve it year after year to obtain a variety that is “tailor made” for your climate and soil.
First, if you are not certain what characteristics you want (high protein, high mineral, high sugar, etc.), buy seed from more than one variety to test. Buy good quality seed with a high germination rate from a reputable company or individual. Some of the large seed companies carry open pollinated seed, as do some small companies and certain individuals. Plant test plots that are separated from one another to avoid cross pollination with other varieties. Be sure your soil is in top-notch condition. Go to extra trouble to control weeds and side dress needed fertilizers. Keep detailed records of all you do: the weather, crop growth and performance, and yield. Test grain for feed value, and if possible do animal feeding tests. Perhaps one variety will prove best for you, or perhaps mixing grain from two or three varieties will give you the best animal feed.
After you have decided on the best variety (or varieties), begin improving that variety by a selection process. There are several ways to improve varieties. The simplest is called mass selection. You just walk through the field (or hunt through the corn crib) and pick out the best looking plants or ears (don’t use cobs from the outside dozen or so rows), collect them (take both ears of two-eared plants) and shell them, mix the kernels all together, and plant that seed next year. Discard kernels at both ends of the cob; those on the central several inches will be more uniform. Sometimes it takes a long time to show much improvement using mass selection.
Another selection process that can give more rapid results is called ear-to-row selection. Again, collect the best ears, but instead of mixing seed from different ears, keep each ear’s seed separate and plant a separate row with each ear (this can be done with an ordinary planter if seed from each cob is put in a separate box). That way you can more rapidly increase the amount of seed from the best ears and eliminate the less desirable characteristics. The best ears from the best rows can be used for next year’s seed. The experimental rows should be in a larger field of the same variety to eliminate stray pollen. To prevent inbreeding in the ear-to-row method, it is best to detassel alternate rows and save seed only from detasseled rows. It would help to record any notable characteristics of each ear, number them, and label each row.
In either method of selection, choose the ears or plants that show the characteristics you want to increase in the next generation, such as height of plant; number of ears; resistance to lodging, disease, or pests; early maturity; ear or kernel size; protein, oil, mineral, or sugar content; yield; etc. But remember that the open pollinated varieties have much genetic variation, not found in commercial hybrids. This genetic variablility is good because it allows the crop to do well in many kinds of conditions. Therefore, don’t expect all plants in the field to look alike, and don’t necessarily choose cobs from identical-looking plants to use for next year’s seed. Instead, focus on the particular traits you wish to increase. It may take several years to get to a desirable level.
After you have developed one or more varieties of your own, you may then want to try variety hybridization to obtain still new varieties of open pollinated corn which may have much improved characteristics. Either two varieties can be planted in alternating rows and be allowed to cross pollinate at random, or one variety can be detasseled and serve as the female parent. The best ears or kernels from detasseled plants can be planted next year. Not all offspring from crosses will have the desired characteristics, but selection over several years may develop a variety that will breed true. Some of the best open pollinated varieties, including the excellent Reid Yellow Dent variety, originated as variety hybrids.
If you engage in growing your own seed corn, you need to take precautions to insure proper storage and good germination. Let the selected ears mature and ripen in the field, but do not let seed be exposed to hard freezes. Select cobs that show the same degree of maturity (all early or all medium). Cobs or seed should be stored in a cool, dry place, away from rodents and stored grain insect pests. Storage at 40–50°F and in a room with a humidity below 13% is best.
Cobs or seed should be laid out so air can circulate. Seed shelled from cobs for ear-to-row planting can be kept in small paper sacks that are left open at the top. If seed corn has to be artificially dried, it should be done slowly at low temperatures (below 107°F). Germination rate should be tested by wrapping about 50 (or more) seeds in a moist paper towel at room temperature. If stored grain pests infest the seed corn (weevils, grain beetles, grain moths), they can be killed without much harm to the seed if the seed is heated to 140°F for 10 minutes. Avoid cracking kernels if a mechanical sheller is used.