Zea Mays,Sweet Corn,the uses and benefit of corn.maize...

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Corn's family tree and spectrum of Corn.

Sweet corn Extract INCI Name Zea Mays Extract CAS 84696-06-0 photo picture image While origins of most major crop species are clearly known, the genealogy of corn has been difficult to establish. The Mexican annual grass teosinte (Zea mays subspecies parviglumis) was identified only quite recently as corn's closest relative. Some ecologists have suggested that teosinte may originally have been cultivated not for its ears, which are numerous and small, but for the sugary pith of its stem.1 Others postulate that corn originated through hybridization of a perennial variety of teosinte, Zea diploperennis, with another grass, Tripsacum dactyloides.

Despite their differences, corn and teosinte are able to form hybrids with one another when grown in the same geographic area. Corn-teosinte crosses produce a "wild corn" known in Mexico as "maiz de coyote," or "coyote corn."Tripsacum species can also hybridize with domesticated corn, although offspring of direct crosses are generally sterile.

By studying corn's history, researchers can identify sources of disease resistance. Zea diploperennis, for example, contains genes for resistance to seven of the nine principal viruses that infect corn crops in the U.S. Hybrids of this species with domestic corn have produced virus-resistant corn now grown in South Africa.5 In another case, a cross between domestic corn and Tripsacum dactyloides-Zea diploperennis hybrids created a corn variety resistant to corn rootworm.
Sweet corn Extract INCI Name Zea Mays Extract CAS 84696-06-0 photo picture image

Corn diversity:

Specific crop varieties developed to fit local conditions and individual farmers' preferences are known as landraces or "criollos." Many potentially important genetic traits are conserved in landraces bred and managed by small farmers. One recent study that looked at diversity in enzymes in Mexican corn found high genetic variation within individual races of corn. This means that conservation efforts focused simply on maintaining genetic material from each race would be insufficient to maintain existing genetic diversity since some diversity appears to be directly linked to location. The study's authors are concerned that rapid replacement of landraces by commercial varieties in some areas could result in loss of valuable genetic material.

Use of hybrids:

Commercial corn producers rely on hybrid corn seed. These hybrid crops are able to reproduce, but their offspring display unpredictable sets of traits and thus are impractical for use on a commercial scale. As a result, commercial corn growers must purchase new seed every year. In contrast, small farmers in Mexico and other developing countries often save corn seed from one year to the next.
Sweet corn Extract INCI Name Zea Mays Extract CAS 84696-06-0 photo picture image

Varieties:

Ornamental Corn - Grow from shelled kernels or order from catalogues. Indian Fingers has thin ears only 3 to 4 inches long.

Popcorn - Yellow: Creme-Puff Hybrid. Early yellow: Tom Thumb. White: Popwhite, White Cloud hybrid, Burpee's Peppy Hybrid. Ornamental: Cutie Pops, Symphonie, Strawberry.

Sweet Corn - The choice is huge. Days to maturity (early, midseason, or late), kernel color (yellow, white, or bicolored), ear size (small, med., lg.) and sweetness (standard, very sweet, super-sweet, or ultra-sweet) are all factors to consider. Super- and ultra-sweet kinds should be isolated so that they won't cross with standard types. Below are a few of the more popular hybrids.

Early standard: Aztec, Early Sunglow, Party time, Polar Vee, Seneca Star. Midseason standard: Candystick, Honey and Cream, Seneca Chief (AAS). Midseason very sweet: Crusader. Midseason super-sweet: Butterfruit Bicolor. Midseason ultra-sweet: How Sweet It Is (AAS). Late Standard: Silver Queen. Late very sweet: Great Taste, Kandy Korn E.H. Late super-sweet: Burpee's Sugar Sweet, Florida Staysweet.

Recommended varieties:

Grain corn - (i) Metro, (ii) Suwan 1 (iii) Suwan 2 (iv) Suwan 3

Sweet corn - (i) Thai Super Sweet, (ii) Hawaiian Super Sweet, (iii) Canadian Rocky, (iv) Honey Jean 11~(Hybrids F1).

Class pictures:

(i)Ruby Queen Hybrid Sweet Corn;(ii)Silver Queen White Corn;(iii)Honey 'n' Pearl Bicolor Corn;(iv)Xtra-Sweet Corn:
Sweet corn Extract INCI Name Zea Mays Extract CAS 84696-06-0 photo picture image

Dent (Zea mays indenata):

Dent corn is often used as livestock feed, in industrial products, or to make processed foods. Dent corn is also frequently referred to as "field" corn. Either white or yellow, dent kernals contain both hard and soft starch that become indented at maturity.

DENT corn, the scientific name of which is Zea mays indentata, is also called "field" corn. It is a corn variety with kernels that contain both hard and soft starch and become indented at maturity. It is a major crop used to make food, animal feed, and industrial products. This is the only variety to be considered for cornstarch manufacturing.

Flint (Zea mays indurata):

Flint corn, also known as Indian corn, is used for similar purposes as dent corn. Flint corn is distinguished by a hard outer shell and kernals with a range of colors from white to red. (You can remember that it has a very hard exterior by thinking of flint, the stone.) Today, most flint corn is grown in Central and South America.

FLINT corn, known by the scientific name Zea mays indurata, is a variety of corn having hard, horny, rounded or short and flat kernels with the soft and starchy endosperm completely enclosed by a hard outer layer. It is similar to dent and is used for the same purposes. Most of it is grown in South America.

Sweet (Zea saccharata or Zea rugosa):

Sweet corn is primarily eaten on the cob, or it can be canned or frozen for future consumption. Sweet corn is seldom used for feed or flour. Sweet corn is extra sweet because it contains more natural sugars than other types of corn. (Field corn contains 4% sugar at the same stage standard sweet corn contains 10% sugar.) Almost 50% of the sugar can be converted to starch only 24 hours after sweet corn is picked, so it is best to eat it fresh!

SWEET or "green" corn is eaten fresh, canned, or frozen. It is a type of corn that is grown in many horticultural varieties. It is variously considered a distinct species (Zea saccharata or Zea rugosa), a subspecies (Zea mays rugosa) or a specific mutation of dent corn. It is distinguished by kernels containing a high percentage of sugar in the milk stage when they are suitable for table use.

Sweet corn is a warm-season vegetable that can be grown easily in any garden with sufficient light, fertility, growing season and space. It is especially popular with home gardeners because it tastes appreciably better when it is harvested and eaten fresh from the garden. Successive plantings can yield continual harvests from early summer until frost if the weather cooperates.

Sweet corn may be divided into three distinct types according to genetic background: normal sugary (SU), sugary enhancer (SE) and supersweet (Sh2).

Standard sweet corn varieties contain a "sugary (SU) gene" that is responsible for the sweetness and creamy texture of the kernels. SUs are best suited to being picked, husked and eaten within a very short time. In the home garden, this is sometimes possible but not always practical. The old adage was "start the water boiling, run to the patch, pick and husk the corn, run back to the pot, cook the corn, and eat or process immediately."

Other kinds of Corn:

WAXY corn is a corn variety with grains that have a waxy appearance when cut, and that contains only branched-chain starch. Waxy corn starch is over 99% amylopectin, whereas regular corn contains 72-76% amylopectin and 24-28% amylose. Amylopectin is a branched form of starch of high molecular weight, while amylose is a smaller unbranched or linear form of starch. Waxy corn is processed in wet milling to produce waxy cornstarch which slowly retrogrades back to the crystalline form of starch. It is grown to make special starches for thickening foods in particularly those that undergo large temperature changes in processing and preparation.

POPCORN is a variety of corn, Zea mays everta, which has small ears and small pointed or rounded kernels with very hard corneous endosperm that, on exposure to dry heat, are popped or everted by the expulsion of the contained moisture, and form a white starchy mass many times the size of the original kernel.

INDIAN corn has white, red, purple, brown, or multicoloured kernels. It was the original corn grown by the Indians, and is known by the scientific name Zea mays. It is many times seen in harvest time and Halloween decorations.

FLOUR corn, also called "soft" corn or "squaw" corn, has kernels shaped like those of flint corn and composed almost entirely of soft starch. It is known by the scientific name Zea mays amylacea. USA grows small amounts of blue flour corn to make tortillas, chips, and baked goods. In South America this corn is grown in various colours to make food and beer.

Sugary enhancer hybrids contain the sugary enhancer (SE) gene, that significantly raises the sugar content above standard SUs while retaining the tenderness and creamy texture of standard varieties. The taste, tenderness and texture are outstanding. SEs are the gourmet corns of choice for home gardeners because they contain the best qualities of both SU and Sh2 types. Fresh from the garden, virtually all current SE releases have eating quality that is superior to all other types. No isolation from standard SUs is necessary.

Supersweet hybrids contain the shrunken -2 gene and have a higher sugar content than the standard SU varieties. The kernels of the extra-sweet varieties have a crispy, tough-skinned texture and contain low amounts of the water-soluble polysaccharides that impart the creamy texture and "corny" flavor to other sweet corn varieties. Although the lack of creamy texture is not especially noticeable in fresh corn on the cob, it affects the quality of frozen and canned corn, as does the toughness of the seed coat. Unless corn must be stored, shipped or mechanically harvested, SEs are superior in eating quality to Sh2s.

Supersweets (Sh2) should be isolated from any other type of corn tasseling at the same time to ensure sweetness and tenderness. Their pollen is weak and easily supplanted by other types, which causes the kernel to revert to a form with the toughness and starchiness of field corn. Because corn is wind-pollinated, this isolation distance can be 500 feet or more, especially downwind.