The tomato (Lycopersicon esculentum) that we know today embarked on a long journey from being discovered and traveling through several countries before coming to the U.S. It originated in the Peru-Ecuador-Bolivia area of the Andes. It was unknown as a food in the U.S. until 1820. It was thought to be poisonous and was called the “love apple.” It is a member of the Solanaceae (nightshade) family, which includes pepper, eggplant, Irish potato and tobacco. The tomato stems have glandular hairs that produce a strong odor when rubbed.
The Italians first grew tomatoes in 1550 and by the middle of the 18th century they were grown in many European countries. Thomas Jefferson grew them in 1781 and they were reported to be growing in New Orleans in 1812. Robert Gibbon Johnson was an American gentleman farmer, historian, horticulturist, judge, soldier and statesman who lived in Salem, NJ. He is especially renowned for the apocryphal story that he publicly ate a basket of tomatoes at the Old Salem County Courthouse in 1820 to demonstrate that they were not poisonous.
People often ask “Is the tomato a fruit or a vegetable?” In 1893, the Supreme Court of the U.S. rendered a decision that the tomato is a vegetable. An importer had argued that tomatoes were fruit and therefore, at that time, not subject to duty. The court held the tomato to be a vegetable because it was served at dinner in, with or after the soup, or with fish or meats that constitute the main part of the meal. However, in botanical terms, the tomato is a fruit because it is made up of ripened ovary tissue.
The tomato we know today is a far cry from the native tomato, which was very small. Over the years, plant breeders have made crosses with the wild tomato and varieties that had superior qualities.
One of the most well-known tomato breeders that made significant accomplishments throughout his career is Dr. Randy Gardner. He began his career heading up the fresh market tomato breeding program at North Carolina State University. He worked at the Mountain Horticultural Crops Research and Extension Center in Mills River, NC. His tireless efforts introducing new tomato varieties were rewarded by growers accepting his new releases.
Gardner strove to find suitable varieties for tomato growers in North Carolina. Some of the varieties he developed include Mountain Pride, Mountain Spring and Mountain Fresh, releasing more than 22 varieties. He is credited with developing varieties used on some 60 – 75% of the vine-ripe tomatoes grown in the eastern U.S.
Gardner retired in 2008 but continues his own plant breeding work, including developing improved heirloom-type tomatoes. He developed Mountain Rouge, a pink tomato with resistance to cracking, late blight and nematodes. He is also developing a wide variety of fresh market tomatoes with different colored flesh and sizes that can be marketed together in a pack to make a colorful display for salads. He is also working on a variety that is green-fleshed when ripe.
He is developing tomato “branding,” similar to selling apples by variety.
It is interesting to learn about the many different types of sweet corn available to growers today and how pollination can influence the starchiness or sweetness of the kernels. It is a member of the grass family Graminae, originating east of the Andes Mountains in South America. Native Americans called it maize, the scientific name being Zea mays. North American corn descended from Central American forms, which are the result of prehistoric hybridization between South American maize and a closely related wild species of Central America having the same ancestor.
Sweet corn is a warm season crop, doing best between 40 – 90º. Soil temperatures should be between 55 – 60º for good germination. At soil temperatures less than 50º, the seed will imbibe water but will rot instead of germinating. Seed is usually spaced 6 – 10” in the row, with three feet between rows. Planting multiple rows will ensure effective cross pollination. The number of rows of kernels on an ear is always even due to cell division.
Standard sweet corn is a mutant type of corn that differs from field or dent corn by a mutation at the sugary (su) locus. The (su) mutation causes the endosperm (storage area) of the seed to accumulate about two times more sugar than field corn. Today, several hundred standard (su) varieties are available. Recently, a number of new mutants have been used to improve sweet corn eating quality, particularly the sugary enhanced (se) and the shrunken-2 (sh2) genes.
The (se) varieties, also called Everlasting Heritage (EH), are well-suited for local market production because they contain more sugars than the normal (su) sweet corn and therefore will remain sweet about two to four days after harvest if refrigerated. The (se) varieties can be grown in the same manner as (su) corn. Sugary enhanced hybrids and normal (su) corn varieties do not require isolation from each other.
The (sh2) sweet corn, also called supersweet, has two main advantages over the other types: It is at least two to three times sweeter, and the conversion of sugar to starch is negligible, thus this corn type will remain sweet up to 10 days after harvest if cooled properly, then refrigerated. Because of these advantages, they are grown for sales to distant markets as well as local markets.
The (sh2) sweet corns must be planted in warm soils (at least 60º) at a two-inch depth. They also need to be isolated at least 300 feet from other corn types, otherwise the corn will be starchy if cross-pollinated. Besides isolation, cross-pollination can be prevented by varying planting dates or selecting varieties so that the pollination stage (silking date) does not overlap with another variety.
For successive sweet corn plantings to extend your harvest season, remember that early plantings in cool soils will be slower to emerge, so wait until the previous planting reaches one or two inches tall before planting the next.
Sweet corn is stored close to 32º to keep it sweet longer. The faster the field heat is removed from the corn, the longer the shelf life. Also, corn husks pull moisture out of the kernels, so husked corn will stay fresher longer under refrigeration than unhusked corn.