Sorghum bicolor, commonly called sorghum and also known as durra, jowari, or milo, is a grass species cultivated for its grain, which is used for food, both for animals and humans, and for ethanol production. Sorghum originated in northern Africa, and is now cultivated widely in tropical and subtropical regions. S. bicolor is typically an annual, but some cultivars are perennial. It grows in clumps that may reach over 4 m high. The grain is small, ranging from 3 to 4 mm in diameter. Sweet sorghums are sorghum cultivars that are primarily grown for foliage, syrup production, and ethanol; they are taller than those grown for grain.^[2][3]

S. bicolor is the cultivated species of sorghum; its wild relatives make up the botanical genus Sorghum.

Cultivation

Seed head of sorghum in India

The leading producers of sorghum bicolor in 2011 were Nigeria (12.6%), India (11.2%), Mexico (11.2%) and the United States (10.0%).^[4] Sorghum grows in a wide range of temperature, high altitudes, toxic soils and can recover growth after some drought.^[2] It has four features that make it one of the most drought-resistant crops:

• It has a very large root-to-leaf surface area.
• In times of drought, it will roll its leaves to lessen water loss by transpiration.
• If drought continues, it will go into dormancy rather than dying.
• Its leaves are protected by a waxy cuticle.

Richard Pankhurst reports (citing Augustus B. Wylde) that in 19th-century Ethiopia, durra was "often the first crop sown on newly cultivated land", explaining that this cereal did not require the thorough ploughing other crops did, and its roots not only decomposed into a good fertilizer, but they also helped to break up the soil while not exhausting the subsoil.^[5]

Uses

red on white sorghum grains

Sorghum is cultivated in many parts of the world today. In the past 50 years, the area planted with sorghum worldwide had increased 66%.^[4] In many parts of Asia and Africa, its grain are used to make flat breads that form the staple food of many cultures.^[6][7] The grains can also be popped in a similar fashion to popcorn.

The species can be used as a source for making ethanol fuel, and in some environments may be better than maize or sugarcane, as it can grow under harsher conditions.^[2] It typically has protein levels of around 9%, enabling dependent human populations to subsist on it in times of famine, in contrast to regions where maize has become the staple crop. It is also used for making a traditional corn broom.^[8]

The reclaimed stalks of the sorghum plant are used to make a decorative millwork material marketed as Kirei board.

Sweet sorghum syrup is known as molasses in some parts of the U.S., although it is not true molasses.

In China, sorghum is fermented and distilled to produce maotai, which is regarded as one of the country's most famous liquors. Sorghum was ground and the flour was the main alternative to wheat in northern China for a long time.

In India, where it is commonly called jwaarie, jowar, jola, or jondhahlaa, sorghum is one of the staple sources of nutrition. An Indian bread, jowar rotti or jolada rotti, is prepared from this grain. In some countries, sweet sorghum stalks are used for producing biofuel by squeezing the juice and then fermenting it into ethanol.^[9] Texas A&M University in the United States is currently running trials to find the best varieties for ethanol production from sorghum leaves and stalks in the USA.^[10]

In Korea, it is cooked with rice, or its flour is used to make cake called susu bukkumi.

In Australia, South America, and the United States (the second largest producer of sorghum after Nigeria), sorghum grain is used primarily for livestock feed and in a growing number of ethanol plants.^[11]

Sorghum is one of a number of grains used as wheat substitutes in gluten-free recipes and products.

Agricultural uses

Sorghum is used in feed for livestock. Its use is limited, however, because the starch and protein in sorghum is more difficult for animals to digest than the starches and protein in corn.^{[citation needed]} Research is being done to find a process that will pre-digest the grain. One study on cattle showed that steam-flaked sorghum was preferable to dry-rolled sorghum because it improved daily weight gain.^[4] In hogs, sorghum has been shown to be a more efficient feed choice than corn when both grains were processed in the same way.^{[clarification needed][4]}

Research

Research is being conducted to develop a genetic cross^{[clarification needed]} that will make the plant more tolerant to colder temperatures, since it is native to tropical climates.^[12] In the United States, this is important because the cost of corn is steadily increasing due to its usage in ethanol production for addition to gasoline. Sorghum silage can be used as a replacement of corn silage in the diet for dairy cattle.^[13] Other research has shown that a timely harvest of sorghum is essential for a safe feed product. The plants need to be harvested during the time when the plant's total moisture content is between 63 and 68 percent, to prevent lodging.^{[clarification needed]} Approximately, this is when the grain reaches the "soft dough" stage.^{[clarification needed]} More research has found that sorghum has higher nutritional value compared to corn when feeding dairy cattle. And the type of processing is also essential in harvesting the grain's maximum nutrition. Feeding steam-flaked sorghum showed an increase in milk production when compared to dry-rolling.^[13] When a grain is steam-flaked, it is cooked slightly, this makes certain nutrients more available to be digested.

Genome

The genome of Sorghum bicolor was sequenced between 2005 and 2007.^[14][15]

Parasite

Sorghum is a host of the parasitic plant Striga hermonthica.^[16] This parasite is a devastating pest on the crop.

See also

• Apigeninidin
• 3-Deoxyanthocyanidin
• List of antioxidants in food
• Commercial sorghum

Notes