Corn seed may be heirloom (natural, open-pollinated, nonhybrid) or hybrid (modified) varieties. Corn grown for human consumption is sweet corn, of which there are many varieties. Corn may be yellow, white, bi-colored or multicolored. It is one of the world's staple foods. One ear of corn has many kernels, which become the seeds from which a new plant grows.
Genetically Engineered Corn
According to the U.S. Department of Agriculture, over 80 percent of all corn grown commercially in the United States today is a genetically engineered (GE) variety. Genetic engineering differs from plant breeding in a very important way. Genetic engineering involves taking genes from other sources (not from a similar plant and perhaps not from a plant at all) and inserting them artificially. Plant breeding, on the other hand, involves crossing two similar plants in a natural manner to achieve more desirable traits.
There is wide-ranging debate and dissent over genetic engineering and companies such as Monsanto that hold patents on GE corn seed. The most common GE corn has been genetically altered to be Roundup resistant. Farmers cannot grow GE corn without paying the patent owner for new seeds annually. In other words, farmers cannot save the seeds from year to year as they always did. It is unknown what the long-term effects of GE foods are on the environment, animals and humans. It is debated whether the GE varieties even increase production as claimed.
Genetically engineered corn is approved for human consumption by many governments. Canada and the United States do not require labeling of products containing GE corn or other GE crops. Europe does require labeling of GE foods.
Sweet Corn Varieties
Some varieties of yellow corn are Earlivee, Early Sunglow, Seneca Horizon, Sundance and Golden Bantam (an heirloom variety). Some varieties of white corn are Country Gentleman and Silver Queen. Stowell's Evergreen is an heirloom white corn. Triple Play is a multicolor, heirloom variety. Double Standard and Honey Creme are two bi-color, heirloom varieties.
A warm season vegetable, successive plantings of corn may yield continual harvests from summer until frost. Corn is traditionally planted in a row garden, but it can be successfully planted in raised beds or containers. It tends to take up a lot of space, as the stalks may grow more than six feet high and a couple of feet wide. Space corn seed accordingly. Warm soil is necessary for germination. The soil temperature should be over 55 degrees F for standard varieties and around 65 degrees F for supersweet varieties. Plant early-harvest varieties after the average last frost date. Successive plantings can be made as late as July in many areas.
Types of Sweet Corn
There are three types of sweet corn: normal sugary (SU), supersweet (Sh2) and sugary enhancer (SE). The sugary enhancer hybrids have a sugary enhancer gene that makes them sweeter than the normal sugary varieties. The supersweet hybrids have a shrunken-2 gene that makes them more sweet than the sugary enhancer variety.
Corn comes from a European word that means kernel. The proper name is Zea mays L. var. rugosa. It is native American in origin and has been cultivated for more than 4,000 years.
The peak freshness for sweet corn is measured in minutes, which is why it tastes so much better fresh from the home garden.
Proper timing for harvest is important. Harvest when ears are blunt at the tip and very full. Husks will be green and tightly folded. The silk should be turning brown and dry on the ends. Take your thumb nail and scratch a kernel. If the sap is milky white, it is ripe and ready. If the sap is a watery liquid, it is under-ripe.
Corn does not store well. It loses quality, flavor and sweetness quickly. If you must store it, sweet corn is best stored in perforated plastic bags in the refrigerator. Wait to husk the corn until immediately prior to cooking.