Peanuts, showing legumes, one split open
revealing two seeds with their
brown seed coats

The peanut is the edible seed of the plant, Arachis hypogaea. Although called a nut, the peanut is a member of the pea family (Family Fabaceae) and the fruit is not a nut, but a legume or pod. Peanuts develop underground in a woody pod, usually with two seeds to a pod. The peanut plant is a hairy, taprooted annual that measures 1 to 1.5 feet in height.

Peanuts are often roasted and salted, but also are often eaten raw, or boiled in salt water. They can also be made into peanut butter, peanut brittle, candy bars, and other products. Peanut oil is often used in cooking, because it has a mald flavor and burns only at a relatively high temperature.

Although most people enjoy many foods made with peanuts, some people have severe allergic reactions to peanuts; eating a single peanut can be fatal. For these individuals, just breathing the dust from peanuts has caused a fatal reaction. Because of this, peanuts are less frequently served on airplanes and peanut products are banned by many school districts for the protection of allergic students. Peanut oil does not contain the same proteins as the whole nut, so very few people are allergic to it. There is now an experimental drug available to combat this allergy, called TNX-901.

Peanuts are also known as groundnuts (because they grow underground), earthnuts, goobers, goober peas, pindas, pinders, Manila nuts and monkey nuts (although the last of these is often used to mean the entire pod, not just the seeds).

Culture

The flower of the Arachis hypogaea is borne above ground and after it withers, the stalk elongates, bends down, and forces the ovary underground. When the seed is mature, the inner lining of the pods (called the seed coat) changes color from white to a reddish brown. The entire plant, including most of the roots, is removed from the soil during harvesting.

The pods begin in the orange veined, yellow petaled, pealike flowers, which are borne in axillary clusters above ground. Following self-pollination (peanuts are complete inbreeders), the flowers fade. The stalks at the bases of the ovaries, called pegs, elongate rapidly, and turn downward to bury the fruits several inches in the ground to complete their development.

The pods act in nutrient absorption. The fruits have wrinkled shells that are constricted between the two to three seeds. The mature seeds resemble other legume seeds, such as beans, but they have paper-thin seed coats, as opposed to the usual, hard legume seed coats.

Peanuts grow best in light, sandy loam soil. They require five months of warm weather, and an annual rainfall of 20 to 40 inches or the equivalent in irrigation water.

The pods ripen 120 to 150 days after the seeds are planted. If the crop is harvested too early, the pods will be unripe. If they are harvested late, the pods will snap off at the stalk, and will remain in the soil.

Wrong storage of peanuts can lead to an infestation by the fungus Aspergillus flavus, releasing the toxic substance aflatoxin.

Types of Peanuts

Four types of peanuts are the most popular: Spanish, Runner, Virginia, and Valencia. There are also Tennessee Red and Tennessee White types. Certain types are preferred for particular uses because of differences in flavor, oil content, size, and shape. For many uses the different types are interchangeable. Most peanuts marketed in the shell are of the Virginia type, along with some Valencias selected for large size and the attractive appearance of the shell. Spanish peanuts are used mostly for peanut candy, salted nuts, and peanut butter. Most Runners are used to make peanut butter.

The various types are distinguished by branching habit and branch length. There are numerous varieties of each type of peanut.

Each year new varieties of peanuts are introduced somewhere in the peanut belt of the U.S. or in other countries. Introducing a new variety may mean change in the planting rate, adjusting the planter, harvester, dryer, cleaner, sheller, and method of marketing.

There are two main growth forms: bunch and runner. Bunch types grow upright, while runner types grow near the ground.

Spanish Types

The small Spanish types are grown in South Africa, and in the southwestern and southeastern U.S. Prior to 1940, 90 percent of the peanuts grown in Georgia were Spanish types, but the trend since then has been larger seeded, higher yielding, more disease resistant varieties.

Varieties of the Spanish type include Dixie Spanish, Improved Spanish 2B, GFA Spanish, Argentine, Spantex, Spanette, Shaffers Spanish, Natal Common (Spanish), White Kernel Varieties, Starr, Comet, Florispan, Spanhoma, Spancross, and Wilco I.

Runner Types

Since 1940, there has been a shift to production of Runner type peanuts in the southeastern U.S. This is due to higher yields and wider use in peanut butter and salting, as compared to Spanish types.

Varieties of Runners include Southeastern Runner 56-15, Dixie Runner, Early Runner, Virginia Bunch 67, Bradford Runner, Egyptian Giant (also known as Virginia Bunch and Giant), Rhodesian Spanish Bunch (Valencia and Virginia Bunch), North Carolina Runner 56-15, Florunner, and Shulamit.

Virginia Types

The large seeded Virginia types are grown in Virginia, North Carolina, Tennessee, and parts of Georgia. They are increasing in popularity due to demand for large peanuts for processing, particularly for salting, confections, and roasting in the shells.

Virginia type peanuts are either bunch or running in growth habit. The bunch type is upright to spreading. It attains a height of 18 to 22 inches, and a spread of 28 to 30 inches, with 33 to 36 inch rows that seldom cover the ground. The pods are borne within a few inches of the base of the plant.

Varieties of Virginia type peanuts include Virginia Bunch Large, Virginia Bunch 46-2, Virginia Bunch Small, Virginia Bunch 67, Virginia Bunch G2, Virginia Runner G26, NC 4X, NC 2, NC 5, Georgia Hybrid 119-20, Holland Jumbo, Holland Station Runner, Adkins Runner, Virginia Runner 26, Virginia Runner G (Holland Virginia Runner), Virginia 56 R, Virginia 61 R, Florigiant, Georgia Hybrid 119-18, Virginia B22-15, Virginia A17-12, Virginia A23-7, and Florida 416.

Valencia Types

Valencia types are coarse, and they have heavy reddish stems and large foliage. They are comparatively tall, having a height of 50 inches and a spread of 30 inches. Peanut pods are borne on pegs arising from the main stem and the side branches. Most of the pods are clustered around the base of the plant, and only a few are found several inches away. Valencia types are three seeded and smooth, with no constriction between the seeds. Seeds are oval and tightly crowded into the pods. There are two strains, one with flesh and the other with red seeds. The seed count is 65 to each ounce.

Tennessee Red and Tennessee White Types

These are alike, except for the color of the seed. The plants are similar to Valencia types, except that the stems are green to greenish brown, and the pods are rough, irregular, and have a smaller proportion of kernels.

Uses

Peanuts for edible uses account for two-thirds of the total peanut consumption in the United States. The principal uses are peanut butter (see peanut butter and jelly sandwich), peanut candy, salted, shelled nuts, and nuts that have been roasted in the shell. Salted peanuts are usually roasted in oil and packed in retail size, transparent plastic bags and hermetically sealed cans. Dry roasted, salted peanuts are also marketed in significant quantities. The primary use of peanut butter is in the home, but large quantities are also used in the commercial manufacture of sandwiches, candy, and bakery products.

Low grade or culled peanuts not suitable for the edible market are utilized in the production of peanut oil, seed and feed.

Peanuts have a variety of industrial end uses. Paint, varnish, lubricating oil, leather dressings, furniture polish, insecticides, and nitroglycerin are made from peanut oil. Soap is made from saponified oil, and many cosmetics contain peanut oil and its derivatives. The protein portion of the oil is utilized in the manufacture of some textile fibers.

Peanut shells are put to use in the manufacture of plastic, wallboard, abrasives, and fuel. They are also used to make cellulose (used in rayon and paper) and mucilage (glue).

Peanut plant tops are used to make hay. The protein cake (oilcake meal) residue from oil processing is utilized as an animal feed and as a soil fertilizer.

George Washington Carver identified more than 300 different uses for peanuts. He encouraged cotton farmers to grow peanuts instead of or in addition to cotton because cotton had leached so much nitrogen from the soil in Alabama, and one of the peanut's properties as a legume is to put nitrogen back into the soil. His purpose in identifying a variety of uses was to encourage the growth of demand for the peanut so it could become a viable cash crop alternative to cotton.

U.S. Department of Agriculture Program for Peanuts

Peanuts have been designated by the United States Congress to be one of America's basic crops. In order to protect domestic industry by keeping prices artificially high, the United States Department of Agriculture (USDA) conducts a Program for Peanuts. Two USDA programs for domestic peanuts are the Price Support Program and the Production Adjustment Program (National Poundage Quota). The Price Support Program consists of a two-tier price support system that is tied to a maximum poundage quota. Domestic peanuts produced subject to the poundage quota are supported at the higher of two prices, while peanuts over quota or those produced on farms not having a quota are supported at the lower rate. The quota support price acts as a floor price for domestic edible peanuts. For producers who fail to fill their quota in any given year, there is a maximum 10 percent over marketing allowance for the subsequent year. Pursuant to the program, producers may place peanuts under nonrecourse loan with the Commodity Credit Corporation (CCC) at the designated support price or they may privately contract for the sale of their crop.

Trade

The major producers/exporters of peanuts are the United States, Argentina, Sudan, Senegal, and Brazil. These five countries account for 71 percent of total world exports. In recent years, the United States has been the leading exporter of peanuts. The major peanut importers are the European Economic Community (EEC), Canada, and Japan. These three areas account for 78 percent of the world's imports.

Although India and China are the world's largest producers of peanuts, they account for a small part of international trade because most of their production is consumed domestically as peanut oil. Exports of peanuts from India and China are equivalent to less than four percent of world trade.

Ninety percent of India's production is processed into peanut oil. Only a nominal amount of hand-picked select-grade peanuts are exported. India prohibits the importation of all oil seeds, including peanuts.

The European Union is the largest consuming region in the world that does not produce peanuts. All of its consumption is supplied by imports. Consumption of peanuts in the EU is primarily as food, mostly as roasted-in-shell peanuts and as shelled peanuts used in confectionery and bakery products.

The average annual imports of peanuts are less than 0.5 percent of U.S. consumption. Two thirds of U.S. imports are roasted, unshelled peanuts. The major suppliers are Singapore, Taiwan, Malaysia, Hong Kong, China, and Canada. The principal suppliers of shelled peanut imports are Argentina and Canada. Most of Canada's peanut butter is processed from Chinese peanuts. Imports of peanut butter from Argentina are in the form of a paste and must be further processed in the U.S. Other minor suppliers of peanut butter include Malawi, China, India, and Singapore.

See also