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the most valuable crop grown in the United States, and one of the four most important crops in the world

ears of corn

Uses of Corn

About two-thirds of the corn grown in the United States goes into livestock feed. Hogs eat almost half the corn crop. Corn provides the base for many kinds of poultry feeds and dairy feeds. Corn and cornstalks are also made into silage, a fermented livestock feed.

Americans eat about 45 pounds of corn per person per year. Many kinds of food are made from the kernels. Corn also provides food indirectly, in the form of the meat and meat products that come from animals raised on corn. Corn, in one form or another, makes up more of our diet than any other farm crop.

Corn may be eaten just as it comes from the ear in succotash, chowder, pudding, popcorn, fritters, parched corn, and as roasted or boiled corn on the cob. Hominy is made by treating the whole grains with lye and washing them carefully. Hominy can then be flavored, rolled out, and toasted to make corn flakes (breakfast cereal). Corn kernels are coarsely ground to make corn meal. Foods made from corn meal include corn bread, cookies, tamales, and waffles.

Corn refining is the process of separating the kernel into its parts. The basic products of refining are starch, sugar, syrup, and oil. Corn oil is used as a salad oil and cooking oil, and in other food products such as margarine and shortening. Cornstarch is used to thicken puddings, gravies, and sauces. It is also used in such products as candy, chewing gum, and baked goods. Corn syrup, made by heating cornstarch in closed tanks, sweetens many foods and is used as a spread for bread.

Corn is also used in the manufacture of hundreds of inedible products. Cornstalks are used to make wallboards and certain kinds of paper. Ground cobs can be substituted for cork. Whole corncobs are sometimes burned as fuel. Corncob meal may be used for fertilizer, for cleaning furs, and for polishing metals. Cobs are also an ingredient of furfural, a chemical used in making plastic, nylon, and other industrial products. Corn meal is used in the manufacture of adhesives, cork products, felts, cleaning compounds, and plywoods.tarch, refined from corn meal, is used to stiffen and finish paper, yarns, and fabrics. Starch also plays a part in the manufacture of cosmetics, explosives, electric batteries, and drugs. Corn sugar has uses in leather tanning, rayon and paper manufacturing, and other industries. Corn oil is used in soaps, glycerine, paints, varnishes, and rubber substitutes. Ethyl alcohol, made from corn sugar or syrup, is an important ingredient in smokeless powder, shatterproof glass, synthetic rubber, brake fluids, and plastics. Ethyl alcohol is also used to make the "10% alcohol" gasoline you buy at the gas station (ethanol).

Kinds of Corn

Dent Corn is the most common commercial variety, comprising about 90 per cent of the corn grown in the United States. Each kernel of corn has a small dent on the top. This dent is made when the hard and soft starch in the kernel shrink unequally as it dries. Farmers harvest dent corn when the seeds become hard and ripe.

Dent corn is primarily used as a livestock feed, but can also be used to make many food and industrial products. It is grown in all parts of the Corn Belt.

Sweet Corn is grown chiefly for human consumption. It must be picked at just the right time to ensure the best flavor. Most sweet corn grows in the northern states, with Wisconsin, Minnesota, and Oregon being the leading sweet corn producers.

Flint Corn has hard kernels with a smooth coat. It can grow in cold climates because it ripens in less time than other kinds of corn. Wisconsin, the New England states, and other northern states grow flint corn. Argentina, a leading world producer of corn, grows almost no other type of corn but flint. Flint corn can be shipped and stored with less spoilage than any other kinds.

Popcorn has small, hard kernels that are either rice-shaped with pointed ends or flat with rounded ends. A tough outer coat covers each kernel. When the kernels are heated rapidly, the moisture inside them turns to steam. This steam builds up a great pressure within the kernel until it finally bursts the kernel's outer shell, and the entire inside of the kernel puffs out. Nebraska, Indiana, Iowa, and Kansas lead in growing popcorn.

Flour Corn, or soft corn, is one of the oldest types of corn. It has soft, starchy kernels. It can be ground by hand because it has softer kernels than any other kinds of corn. Flour corn grows in the warm areas of South America, but is not grown commercially in the United States.

Pod Corn has a separate covering around each kernel. In all other corns, the kernel has no separate covering. It has never been grown commercially, because the husks on each kernel make it hard to use.

the six main kinds of corn

The Corn Plant

Corn is a member of the grass family (Gramineae), and belongs to the group of six true grains, or cereals, that also includes wheat, barley, oats, rice, and rye. The corn plant grows 3 to 10 feet tall and has many short ear shoots, or branches.

The tough, jointed cornstalk, or stem, resembles bamboo. It has a central core of pith. A root system with branches supports the green stalk. Sometimes prop roots grow out of the stalk above the ground to help support the plant against the wind. The tassel grows at the top of the cornstalk. It contains hundreds of small flowers that produce pollen. Most corn flowers are pink, but they may be green, yellow, red, or purple.

At each joint of the stem, a long, swordlike leaf curves outward and downward, ending in a pointed tip. The lower part of the leaf partly encloses the stem, forming a sheath. The blade is long, narrow, and pointed.

the corn plant

Ears of corn grow from the places where the leaves join the stalk. A corn plant may have one ear, or as many as eight. Husks (a special kind of leaf) enclose and protect each ear. An ear consists of a corncob covered with rows of kernels, the seeds of the corn plant. An even number of rows usually grow on the ear. An ear may have 8, 10, 12, or more rows of kernels. Each kernel has what looks like a silk thread than runs from the kernel up the row, and sticks out of the husk at the end of the ear. This thread is called the corn silk.

an ear of corn, showing the threads of corn silk

Every kernel has three parts: (1) the hull, or outer covering; (2) the germ, or young embryo corn plant; and (3) the endosperm, which makes up the rest of the kernel. The endosperm is made of hard starch and soft starch. Different kinds of corn have different amounts of these two kinds of starch in their kernels.


Botanists believe that corn first grew somewhere in North America. Fossilized pollen grains from corn plants found in Mexico may be more than 60,000 years old. Ears of corn about the size of strawberries have also been discovered in Mexico. They may be 3,000 years old.

When the first explorers reached North America, they found that the American Indians were growing corn from Canada to the southern tip of South America. The Indians grew all the main types of corn that are raised today, as well as varieties that had red, blue, pink, and/or black kernels. Indians showed the early settlers from Europe how to grow corn, and corn soon became extremely important to the life of the colonists.


Corn grows in almost every state, but three-fourths of the corn produced in the United States grows in the Corn Belt. This area includes Illinois, Indiana, Iowa, Minnesota, Missouri, Nebraska, Ohio, and South Dakota. Leaders in the United States corn production include Iowa, Illinois, Indiana, and Nebraska. The United States produces about 50 per cent of the world total. Other major corn-producing nations include Argentina, Brazil, China, France, Mexico, and South Africa.

map of major corn-growing states

Scientific Classification

Division Magnoliophyta
Class Liliatae
Order Cyperales
Family Gramineae
Genus and Species Zea mays

See Also


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The Robinson Library >> Field Crops

This page was last updated on 09/17/2018.