Brief SummaryRead full entry
Wheat is one of the most ancient of domesticated crops, with archaeological evidence of the cultivation of various species in the Fertile Crescent dating back to 9,600 B.C. The various species have been developed into thousands of cultivars (over 25,000, by one estimate) that differ in chromosome number from the primitive diploid types, with 7 pairs of chromosomes, to hybrid allopolyploids, with 14, 21, and 28 chromosome pairs. Durum wheat was developed from wild emmer or kamut (T. turgidum), and has larger, harder grains and a higher protein content and lower gluten content that bread wheat (T. aestivum varieties). Durum wheat varieties are hardy and drought-resistant, often grown in dry regions, and are mostly planted in the spring--in contrast to many bread wheat varieties, known as winter wheat because they are planted in the fall and allowed to overwinter.
Wheat is high in carbohydrates, protein (although lacking several essential amino acids), and vitamins B and E (if the grain is left whole); durum wheat is slightly lower than bread wheat in nutrient content. Because of its low gluten content, durum wheat is not used for bread and baked goods, but is wheat used in pasta, semolina (cream of wheat), the Middle Eastern bulgar (wheat that has been boiled, dried, and cracked, and is then prepared like rice and used similarly or prepared into salads such as tabouleh), and North African couscous, which is actually small pellets of pasta.
The FAO estimates that global commercial production of all types of wheat was 650.9 million metric tons in 2010, harvested from 217.0 million hectares; it is grown on around 4% of the planet’s agricultural land. Leading producers were China, India, the U.S., the Russian Federation, and France. Within the U.S., the states that were leading producers include Kansas, Montana, North Dakota, South Dakota, Idaho, and Washington.
(Bailey et al. 1976, FAOSTAT 2012, Flora of China 2006, Hedrick 1919, USDA 2012, van Wyk 2005.)