Wheat

Resources

Wheat is one of the oldest and most important cereal crops. Wheat is grown for its grain, which is ground into flour used to make breads and pastas. Wheat consists of approximately 20 species in the genus Triticum of the grass family (Poaceae). The most important wheats are: Triticum aestivum, used to make bread; T. durum, used to make pasta; and T. compactum, used to make softer cakes, crackers, cookies, and pastries.

Wheat plants have slender leaves and, in most varieties, long hollow stems. Each stem is topped by a single head or spike, which is an aggregation of 20-100 individual flower clusters called spikelets. Each flower cluster may contain up to six flowers, and each fertilized flower produces a single, edible grain.

About 13% of the mass of the ripe grain is formed by the fused layers of the fruit wall, seed coat, and aleurone. These layers, known as the bran, are nutritionally important because they contain fiber, some protein, and the vitamins thiamine, riboflavin, niacin, and vitamin A. About 84% of the grain is endosperm, a food-storage tissue that consists mainly of starch. The embryo, or germ, represents only 2.5% of the grain and contains most of the oil and protein. Because wheat provides a balance of several vitamins, starch, proteins, and oils, it is an excellent source of nutrition. Furthermore, because of its small water content, generally about 12%, wheat grains are easily transported and stored, and are resistant to microbial spoilage.

Wheat was one of the first plants to be domesticated. Along with barley (Hordeum vulgare ), wheat provided the agronomic basis for development of the earliest civilizations in Mesopotamia, and has been found at archaeological sites in the region dating back to 7000 BC. The cultivation of wheat gradually spread by trade from Mesopotamia to other parts of the world, becoming established in India by 3000 BC, and in Europe by 2000 BC. Wheat did not occur in the New World until brought there by the Spanish in 1520. Wheat was introduced by settlers to the United States in the early 1600s. Nowadays, wheat is grown on every arable continent, and it is the most important food for people living in temperate regions of the world (it is replaced by rice in the tropics).

By far the most important wheat is the common bread wheat (Triticum aestivum ). This species evolved by a series of natural hybridizations followed by chromosome doubling (polyploidy) about 6,000 years ago in the Middle East, where its wild relatives still occur. The first hybridization is believed to have been between a primitive einkorn wheat (Triticum urartu ) and an unknown species of wild goat grass (related to Triticum speltoides ), each with 14 chromosomes. The resulting hybrid doubled its chromosome number and became fertile, producing emmer wheat (Triticum turgidum ) with 28 chromosomes. Emmer wheat then hybridized with another wild species of goat grass (Triticum tauschii ), which had 14 chromosomes, and the hybrid doubled its chromosome number to produce bread wheat with 42 chromosomes. Some of this hybridization and chromosome doubling has been duplicated experimentally in modern times, to yield an “artificial” wheat that resembles certain cultivars of bread wheat.

Winter wheats are planted in the fall and germinate before winter. The seedlings can survive cold winter temperatures–in fact, the low temperatures are needed for proper growth and development of the grain. The seedlings start growing again in the spring as soon as the frost is out of the ground, and by late spring the mature plants are ready for harvest. In contrast, spring wheats are planted in the spring and harvested in the fall.

For thousands of years, wheat was laboriously harvested using a sickle, and then threshed, or beaten, to separate the grains from the heads and flower parts (chaff). In the first half of the 1800s, the reaper was developed, which mechanized cutting and greatly reduced the amount of labor required. Nowadays, cutting the standing plants, threshing the heads, separating the grain from the chaff, cleaning the grain, and discharging it into bags, are all combined in a large, self-propelled machine called a combine.

About 25% of the world’s farmland is devoted to wheat cultivation. This is more than is used for any other crop. About 566 million acres (229 million ha) are sown to produce 478 million U.S. tons (527 million metric tons) of wheat. The world’s greatest wheat producing countries are: the United States, China, Ukraine, India, Canada, Australia, Turkey, and Pakistan. The major wheat-exporting countries are the United States, Australia, Canada, and Argentina. Nearly all wheat-growing countries have breeding programs to improve the races of wheat adapted to local conditions. These programs strive to enhance qualities such as yield, disease and insect resistance, and nutrient content of the grain.

If wheat grains are eaten whole or ground whole by traditional stone grinding, all of the nutrients are retained. Modern milling methods, however, remove the germ and bran, thereby eliminating most of the

KEY TERMS

Aleurone —The protein-rich, outer layer of the endosperm in cereal grains.

Bran —The fused fruit wall, seed coat, and aleurone layer of a cereal grain. It is usually removed during the milling process.

Cereal —A member of the grass family with edible grains, such as oats, barley, rye, maize, and wheat.

Combine —A self-propelled, tractor-like machine that combines the separate functions of cutting, threshing, cleaning, and bagging grains.

Endosperm —The food-storage tissue of a seed of a flowering plant. It consists mostly of starch.

Germ —The embryo of a grain.

Grain —The dry, one-seeded fruit of a grass, differing from other one-seeded fruits (such as nuts and achenes) by having the fruit wall fused to the seed. Known botanically as a caryopsis.

Leavened bread —Wheat bread that has been made to raise by the action of its dough trapping carbon dioxide gas produced by yeast, baking soda, or baking powder.

Wheat flour —The powder that results from grinding grains of wheat.

White flour —Wheat flour made from grains having the bran and embryo removed.

Whole-wheat flour —Flour made from milling the whole grain; that is, grain with the endosperm, bran, and embryo left intact.

proteins, oils, and nearly all vitamins. The resulting white flour stores longer and tastes good but is nutritionally impoverished. For this reason, white flour is often artificially enriched with vitamins to improve its nutritional value.

Wheat flour is primarily used to bake bread. Wheat flour is especially suited for this purpose because it contains two proteins, glutenin and gliadin (collectively known as gluten), that make a sticky, elastic dough. During baking, the dough traps bubbles of carbon dioxide produced by yeast or by chemical leaveners such as baking powder or baking soda. The trapped bubbles cause the bread to rise. (The holes you see in sliced bread were formed by trapped gas bubbles.) Other cereal grains, such as rice, barley, corn, and oats, do not contain glutenin and gliadin and therefore are not suitable for making leavened bread.

Durum wheat (Triticum durum ) does not rise as well as bread wheat because of the different protein composition of its grain. Therefore, durum wheat is used for making spaghetti, macaroni, and other kinds of pasta. Other products made from wheat include bulgur, which is prepared by cooking, dehydrating, and peeling wheat. Wheat germ, which is removed in the milling process, has a large content of vitamin E and protein, and is often added to or sprinkled on other foods as a nutritional supplement. Entire wheat grains, either rolled or puffed, are often used in breakfast cereals. In addition, starch and gluten are extracted from wheat grains. The starch is used in laundering and in making a sweet syrup. The gluten is used in making monosodium glutamate (MSG), a flavor enhancer of cooked foods, especially commonly used in oriental cooking. Wheat is the most important grain fed to poultry. However, wheat is not generally fed to livestock, because it is more expensive than other suitable grains such as maize, barley, and oats.

See also Grasses.

Resources

BOOKS

Chopra, V.L. and Shyam Prakash, eds. Evolution and Adaptation of Crops: Volume 1, Cereals. Enfield, New Hampshire: 2002.

Robbin C. Moran

Wheat

Wheat is one of the oldest and most important cereal crops . Wheat is grown for its grain, which is ground into flour used to make breads and pastas. Wheat consists of approximately 20 species in the genus Triticum of the grass family (Poaceae). The most important wheats are: Triticum aestivum, used to make bread; T. durum, used to make pasta; and T. compactum, used to make softer cakes, crackers, cookies, and pastries.

Wheat plants have slender leaves and, in most varieties, long hollow stems. Each stem is topped by a single head or spike, which is an aggregation of 20-100 individual flower clusters called spikelets. Each flower cluster may contain up to six flowers, and each fertilized flower produces a single, edible grain.

About 13% of the mass of the ripe grain is formed by the fused layers of the fruit wall, seed coat, and aleurone. These layers, known as the bran, are nutritionally important because they contain fiber, some protein, and the vitamins thiamine, riboflavin, niacin, and vitamin A. About 84% of the grain is endosperm, a food-storage tissue that consists mainly of starch. The embryo, or germ, represents only 2.5% of the grain and contains most of the oil and protein. Because wheat provides a balance of several vitamins, starch, proteins , and oils, it is an excellent source of nutrition . Furthermore, because of its small water content, generally about 12%, wheat grains are easily transported and stored, and are resistant to microbial spoilage.

Wheat was one of the first plants to be domesticated. Along with barley (Hordeum vulgare), wheat provided the agronomic basis for development of the earliest civilizations in Mesopotamia, and has been found at archaeological sites in the region dating back to 7000 b.c. The cultivation of wheat gradually spread by trade from Mesopotamia to other parts of the world, becoming established in India by 3000 b.c., and in Europe by 2000 b.c. Wheat did not occur in the New World until brought there by the Spanish in 1520. Wheat was introduced by settlers to the United States in the early 1600s. Nowadays, wheat is grown on every arable continent , and it is the most important food for people living in temperate regions of the world (it is replaced by rice in the tropics).

By far the most important wheat is the common bread wheat (Triticum aestivum). This species evolved by a series of natural hybridizations followed by chromosome doubling (polyploidy) about 6,000 years ago in the Middle East, where its wild relatives still occur. The first hybridization is believed to have been between a primitive einkorn wheat (Triticum urartu) and an unknown species of wild goat grass (related to Triticum speltoides), each with 14 chromosomes. The resulting hybrid doubled its chromosome number and became fertile, producing emmer wheat (Triticum turgidum) with 28 chromosomes. Emmer wheat then hybridized with another wild species of goat grass (Triticum tauschii), which had 14 chromosomes, and the hybrid doubled its chromosome number to produce bread wheat with 42 chromosomes. Some of this hybridization and chromosome doubling has been duplicated experimentally in modern times, to yield an "artificial" wheat that resembles certain cultivars of bread wheat.

Winter wheats are planted in the fall and germinate before winter. The seedlings can survive cold winter temperatures—in fact, the low temperatures are needed for proper growth and development of the grain. The seedlings start growing again in the spring as soon as the frost is out of the ground, and by late spring the mature plants are ready for harvest. In contrast, spring wheats are planted in the spring and harvested in the fall.

For thousands of years, wheat was laboriously harvested using a sickle, and then threshed, or beaten, to separate the grains from the heads and flower parts (chaff). In the first half of the 1800s, the reaper was developed, which mechanized cutting and greatly reduced the amount of labor required. Nowadays, cutting the standing plants, threshing the heads, separating the grain from the chaff, cleaning the grain, and discharging it into bags, are all combined in a large, self-propelled machine called a combine.

About 25% of the world's farmland is devoted to wheat cultivation. This is more than is used for any other crop. About 566 million acres (229 million hectares) are sown to produce 478 million U.S. tons (527 million metric tons) of wheat. The world's greatest wheat producing countries are: the United States, China, Ukraine, India, Canada, Australia , Turkey, and Pakistan. The major wheat-exporting countries are the United States, Australia, Canada, and Argentina. Nearly all wheat-growing countries have breeding programs to improve the races of wheat adapted to local conditions. These programs strive to enhance qualities such as yield, disease and insect resistance, and nutrient content of the grain.

If wheat grains are eaten whole or ground whole by traditional stone grinding, all of the nutrients are retained. Modern milling methods, however, remove the germ and bran, thereby eliminating most of the proteins, oils, and nearly all vitamins. The resulting white flour stores longer and tastes good but is nutritionally impoverished. For this reason, white flour is often artificially enriched with vitamins to improve its nutritional value.

Wheat flour is primarily used to bake bread. Wheat flour is especially suited for this purpose because it contains two proteins, glutenin and gliadin (collectively known as gluten), that make a sticky, elastic dough. During baking, the dough traps bubbles of carbon dioxide produced by yeast or by chemical leaveners such as baking powder or baking soda. The trapped bubbles cause the bread to rise. (The holes you see in sliced bread were formed by trapped gas bubbles.) Other cereal grains, such as rice, barley, corn, and oats, do not contain glutenin and gliadin and therefore are not suitable for making leavened bread.

Durum wheat (Triticum durum) does not rise as well as bread wheat because of the different protein composition of its grain. Therefore, durum wheat is used for making spaghetti, macaroni, and other kinds of pasta. Other products made from wheat include bulgur, which is prepared by cooking, dehydrating, and peeling wheat. Wheat germ, which is removed in the milling process, has a large content of vitamin E and protein, and is often added to or sprinkled on other foods as a nutritional supplement. Entire wheat grains, either rolled or puffed, are often used in breakfast cereals. In addition, starch and gluten are extracted from wheat grains. The starch is used in laundering and in making a sweet syrup. The gluten is used in making monosodium glutamate (MSG) , a flavor enhancer of cooked foods, especially commonly used in oriental cooking. Wheat is the most important grain fed to poultry. However, wheat is not generally fed to livestock , because it is more expensive than other suitable grains such as maize, barley, and oats.

See also Grasses.

Robbin C. Moran

KEY TERMS

Aleurone

—The protein-rich, outer layer of the endosperm in cereal grains.

Bran

—The fused fruit wall, seed coat, and aleurone layer of a cereal grain. It is usually removed during the milling process.

Cereal

—A member of the grass family with edible grains, such as oats, barley, rye, maize, and wheat.

Combine

—A self-propelled, tractor-like machine that combines the separate functions of cutting, threshing, cleaning, and bagging grains.

Endosperm

—The food-storage tissue of a seed of a flowering plant. It consists mostly of starch.

Germ

—The embryo of a grain.

Grain

—The dry, one-seeded fruit of a grass, differing from other one-seeded fruits (such as nuts and achenes) by having the fruit wall fused to the seed. Known botanically as a caryopsis.

Leavened bread

—Wheat bread that has been made to raise by the action of its dough trapping carbon dioxide gas produced by yeast, baking soda, or baking powder.

Wheat flour

—The powder that results from grinding grains of wheat.

White flour

—Wheat flour made from grains having the bran and embryo removed.

Whole-wheat flour

—Flour made from milling the whole grain; that is, grain with the endosperm, bran, and embryo left intact.

WHEAT

WHEAT. Throughout American history wheat has been the principal bread cereal. It was introduced by the first English colonists and early became the major cash crop of farmers on the westward-moving frontier. In colonial times its culture became concentrated in the middle colonies, which became known as the bread colonies. In the mid-eighteenth century, wheat culture spread to the Tidewater region of Maryland and Virginia, where George Washington became a prominent grower.

As the frontier crossed the Appalachian Mountains, so did wheat raising. The census of 1840 revealed Ohio as the premier wheat-producing state, but twenty years later Illinois took the lead; it retained its leading position for three decades, until Minnesota overtook it in 1889. Leadership moved with the farming frontier onto the Great Plains in the first years of the twentieth century. Census takers in 1909 found North Dakota to be the nation's top producer, followed by Kansas. Between 1919 and 1975 the order was reversed, except in 1934 and 1954, when Oklahoma and then Montana moved into second place. In the meantime, the soils of the Columbia River Valley became productive, with the state of Washington ranking fourth in wheat production in 1959.

The majority of the farmers east of the Mississippi River preferred soft winter wheat varieties, such as the Mediterranean (introduced in 1819), but those who settled the Great Plains found those varieties ill-adapted to the region's climates. Hard red spring wheats, such as Red Fife and Bluestem, proved more suited to the northern plains, while Turkey, a hard red winter wheat introduced into central Kansas by German Mennonites who had immigrated from Russia, became popular on the southern plains. The introduction of these hard wheats prompted a major change in the technology of grinding of wheat into flour: a shift from millstones to rollers.

Wheat growers soon developed more varieties better adapted to different regions. Early maturing Marquis was introduced from Canada in 1912, and by 1929 it made up 87 percent of the hard spring wheat acreage in the United States. It proved susceptible to black stem rust, however, and after 1934 it lost favor to Thatcher and, in the late 1960s, to Chris and Fortuna varieties. On the southern plains, Tenmarq, released by the Kansas Agricultural Experiment Station in 1932, superseded Turkey and was in turn replaced first by Pawnee and later by Triumph and Scout. In the 1960s the wheat growers of the Columbia Valley began to favor a new short-stemmed soft white winter wheat, known as Gaines, which doubled yields in that area within a four-year period.

Whatever the variety, in the colonial and early national period farmers sowed wheat by broadcasting (scattering seed by hand over a wide area), reaped mature wheat using sickles, and threshed the harvested grain with flails. In rapid succession in the nineteenth century, sowing with drills replaced broadcasting, cradles took the place of sickles, and reapers and binders in turn replaced cradles. Steam-powered threshing machines superseded flails. In the 1930s the small combine joined reaping and threshing into a single operation. Such technological advances greatly increased the nation's wheat production while cutting the labor requirements per bushel.

The handling and marketing of wheat went through parallel changes. Initially, laborers sacked, shipped, and unloaded the harvest into storage warehouses by hand, but after the Civil War railroads began to construct large grain elevators at country railroad stations and even larger elevators in terminal markets. Grain exchanges there sold the wheat to flour millers and exporters, and a futures market developed for speculators. However, farmers soon accused elevator operators of undergrading, shortweighting, and excessive dockage and began to seek active control over marketing through the organization of cooperatives.

Since colonial times, American wheat growers have produced a surplus for export. Exports of wheat and flour varied from 868,500 bushels in 1814 to 223.8 million bushels in 1898, providing foreign exchange that helped to finance the nation's industrialization. However, expansion of acreage during World War I and contraction of overseas demand after the armistice created an accumulation of surpluses that could not be marketed. The resulting low prices prompted growers to seek government price supports, first through the McNary-Haugen Bill, which failed to become law, and later through the Agricultural Adjustment Act of 1933 and its many revisions. Increasing production, which reached one billion bushels in 1944, permitted an expansion of wheat and flour exports as part of the nation's foreign assistance programs. In fiscal year 1966 these exports amounted to 858.7 million bushels, of which some 571 million were disposed of as food aid. A disastrous drought in the Soviet Union in 1972 led to the sale of 388.5 million bushels to that country in one year and the conclusion in 1975 of an agreement to supply the Soviets with breadstuffs over a five-year period.

BIBLIOGRAPHY

Brumfield, Kirby. This Was Wheat Farming: A Pictorial History of the Farms and Farmers of the Northwest Who Grow the Nation's Bread. Seattle, Wash.: Superior Publishing, 1968.

Hadwiger, Don F. Federal Wheat Commodity Programs. Ames: Iowa State University Press, 1970.

Malin, James C. Winter Wheat in the Golden Belt of Kansas. Lawrence: University of Kansas Press, 1944.

Quisenberry, K. S., and L. P. Reitz. "Turkey Wheat: The Cornerstone of an Empire." Agricultural History 48 (1974): 98– 110.

Robert G.Dunbar/c. w.

See alsoAgriculture ; Cereal Grains ; Dry Farming ; Elevators, Grain ; Gristmills ; Insecticides and Herbicides .

WHEAT

WHEAT , grain belonging to the genus Triticum, of which many species exist. Several species of Triticum are grown in Israel, some called ḥittah (pl. ḥittim) and others kussemet, kusmin, and shippon (for this identification see *Five Species).

(1) Ḥittah is the name applied to two species grown in Israel: hard wheat – Triticum durum, and bread wheat – Triticum vulgare (aestivum). The former is called "dark" and the latter "white" in the Mishnah (bb 5:6). The name ḥittah, with slight variations, is common to all the Semitic languages, mostly in the form of ḥintah, connected with the verb ḥanot ("to project"), because the grains project from the pales of the ear of the wheat when it ripens. In rabbinic literature these are termed levush ("garment"). When threshed, these levushim disintegrate and the grain emerges. Hence the saying: "In the time to come [at the resurrection] the righteous will rise [dressed] in their own clothes. This can be deduced a fortiori from a grain of wheat. If a grain of wheat that is buried naked sprouts up with many garments …" (Ket. 111b). Ḥittah is the most valuable of the five species of cereal. According to one aggadah, "the tree of knowledge was ḥittah" (Sanh. 70b). It is mentioned first among the seven species with which Israel is blessed (Deut. 8:8). It requires good and well-tilled land, and an abundance of ḥittim symbolizes well-being and peace (Ps. 81:17).

Wheat, like *barley, is sown at the beginning of the winter, but it develops more slowly (Ex. 9:31–32) and ripens about two months after barley, from which the Omer is brought on Passover. Seven weeks later "the firstfruits of the ḥittim harvest" are offered (Ex. 34:22). Ezekiel (27:17) mentions "ḥittim of Minnith" which "Judah and Israel" peddled, the reference being to the locality of Minnith in the land of Ammon (Judg. 11:33). Similarly, Arbelite and Midian ḥittim are mentioned as excellent varieties (tj, Sot. 9:13, 24b; Shab. 9:6, 12b). The aggadah refers to 500 confections made from ḥittim (Lam. R. 3:17 no. 6). The choicest ḥittim, used in meal-offerings, came from Michmas and Zoniḥah (Men. 8:1). Wheat was dearer than barley, and according to Josephus (Wars 5:427), it was the food of the rich. During the time of the Mishnah and Talmud, however, when the agricultural situation in Israel improved, wheat became the common food of all. "One who grows wheat is sure of his bread, but one who buys wheat in the market, his future is doubtful" (Men. 103b).

(2) Kussemet or kusmin has been identified with emmer wheat – Triticum dicoccum, a plant which has grown in Israel from earliest times. Remnants have been found in excavations in Israel and in Egyptian tombs. A similar species, Triticum dioccoides, grows wild in Israel and apparently is the species from which emmer wheat originated. The discovery of this species by Aaron *Aaronsohn in Rosh Pinah in 1906 caused a sensation in the botanical world. He maintained that it was the "mother" of all species of wheat, an opinion still upheld by some botanists. The general opinion, however, is that it is the "mother" of emmer wheat only. Like the ḥittah, the kussemet was not smitten by the hail in Egypt because it ripens late and its growth is slow (Ex. 9:32). Isaiah (28:25) enumerates it among the crops sown by the farmer, and it was also included in the mixed bread that Ezekiel ate for 390 days (Ezek. 4:9). In rabbinical literature it is always included among the five species of corn. In taste it is very like ḥittah (Ḥal. 4:2; Pes. 35a), but its nutritional value in relation to bulk is less because of the chaff that sticks to the grains (bm 40a). To remove these husks the wheat was moistened and trodden by cattle so as to release the grain (bm 89b and Rashi). In Aramaic kussemet is called gulba (Men. 70a), a word meaning "cut" or "shorn," a similar connotation to kussemet, which comes from kasam meaning "clipper of hairs" (cf. Ezek. 44:20). The name derives from the short hairs of the ears which look as though they have been cut. Another species of wheat, spelt wheat or Triticum spelta, identified by some commentators with kussemet, has similar characteristics, but no remnants of spelt from the biblical period have been found in the region. It seems that it is the shippon of rabbinical literature.

(3) Shippon is also enumerated among the five species of corn. For the law of *mixing of species it is regarded as belonging to the same species as kussemet (kusmin; Kil. 1:1), but in taste it is associated with barley (Pes. 35a). These indications are compatible with spelt, which resembles emmer wheat but has a barley flavor. Apparently its growth was not very widespread (at the present day also, its growth is very limited), and it is mentioned only a few times in rabbinical literature. This identification is mentioned by the Arukh (s.v.dashr). Now, however, it is usual, following Rashi, to identify shippon with rye – Secale cereale. This identification cannot be accepted, as this plant is not suited to the conditions of Ereẓ Israel and was not grown there. It is also erroneous, as is usually done, to apply the name kussemet to buckwheat – Fagopyrum esculeutum – since it was never grown in Israel and does not fit any of the descriptions of kussemet.

bibliography:

Loew, Flora, 1 (1926), 767–801; J. Feliks, Olam ha-Ẓome'aḥ ha-Mikra'i (1968²), 142–51; idem, Kilei Zera'im ve-Harkavah (1967), 27–32. add. bibliography: Feliks, Ha-Ẓome'aḥ, 60, 83, 161.

[Jehuda Feliks]

Wheat

Wheat, widely cultivated crop important to Latin America's large-scale agribusiness as well as to small-scale peasant cultivation. Christopher Columbus introduced wheat to the New World in 1493, and the following year the first crops were reaped. The early settlers planted typical Spanish wheats of the day, such as Triticum vulgare. Eventually, however, hardier varieties of common wheat (Triticum aestivum), used in making bread and pastry, and durum wheat (Triticum turgidum), used in making pastas, replaced the original species. Although wheat was grown primarily for domestic use throughout the region, wheat-flour consumption tends to be highest where European influences have predominated, as in Chile and Argentina, whereas in areas where indigenous and African cultures have persevered, maize, rice, and manioc remain the principal sources of starch.

In the late nineteenth and early twentieth centuries, wheat became commercially important in a few Latin American countries. In the 1880s, for example, Argentina started to produce a large enough surplus to become a leading wheat-exporting nation. Seeking farmers to raise alfalfa as cattle feed, the cattle barons of the Argentine pampas attracted European peasants by offering them sharecropping arrangements. To prepare the land for alfalfa, the immigrants grew wheat, which proved a successful crop in its own right. Other major producer nations include Brazil, Chile, Mexico, and Uruguay, but none produces surpluses rivaling Argentina's.

Originally domesticated in the Near East, wheat is not naturally suited to Latin America's tropical climate. It grows best where temperatures are mild and rainfall moderate. This explains the success of wheat cultivation in temperate subtropical regions like the belt of the grassland extending from Rio Grande do Sul in Brazil southwest through Uruguay to Buenos Aires province in Argentina. Depending on seasonal climatic conditions, wheat also does well at high altitudes, such as in the central plateau of Mexico and the highland valleys of Ecuador.

The development of high-yield, rust-resistant wheat varieties has been the focus of considerable scientific investigation in Latin America. Experimental farms established in Argentina and Uruguay before World War I eventually bred durable grains that were well adapted to local climates and mechanical harvesting. In Mexico, a green revolution study initiated in 1943 with Rockefeller Foundation participation yielded a stout, semi-dwarf hybrid that withstood the weight of fertilizers without falling over. These discoveries helped wheat growers around the world.

Despite the fact that the improved varieties and the machines made to harvest them generally were available only to large-scale agribusiness, small-scale peasant agriculture contributed greatly to wheat production in many Latin American countries. Studies conducted in the 1970s showed that peasants produced nearly one-third of the wheat consumed in Mexico and 70 percent in Colombia. In sharp contrast to farming wheat from the air-conditioned cab of a modern combine, these peasant farmers often planted, tended, and harvested by hand. Improving their productivity and conditions continued to be a compelling problem in Latin America, for the region as a whole remained dependent on wheat imports: more than 8.2 million short tons were imported in 1989 alone. Critics of the agribusiness blame this situation on the few powerful brokers that control most of the world wheat trade. However, Argentina has become a major exporter of wheat since the 1990s, when the Argentine government eliminated the tax on wheat that had held back production. Also, in 1994 the Southern Common Market (Mercosur) trading pact lowered the tariffs on wheat between Brazil and Argentina. This change helped Argentina become Brazil's principal wheat supplier and aided its return as a major exporter in the world market.

See alsoMercosur .

BIBLIOGRAPHY

James R. Scobie, Revolution on the Pampas: A Social History of Argentine Wheat, 1860–1910 (1964).

Rudolph F. Peterson, Wheat: Botany, Cultivation, and Utilization (1965).

Roger Burbach and Patricia Flynn, Agribusiness in the Americas (1980).

Emiliano Ortega, "Peasant Agriculture in Latin America," in CEPAL Review 16 (April 1982): 75-111.

Charles B. Heiser, Jr., Seed to Cultivation: The Story of Food, new ed. (1990), pp. 67-79.

Additional Bibliography

Adelman, Jeremy. Frontier Development: Land, Labour, and Capital on the Wheatlands of Argentina and Canada, 1890–1914. Oxford: Clarendon Press, 1994.

Gelman, Jorge. Campesinos y estancieros. Buenos Aires: Editorial Los Libros del Riel, 1998.

                                          Cliff Welch