Pearl millet (Pennisetum glaucum) is the most widely grown type of millet. Grown in Africa and the Indian subcontinent since prehistoric times, it is generally accepted that pearl millet originated in Africa and was subsequently introduced into India. The earliest archaeological records in India date to 2000 BC, so domestication in Africa must have taken place earlier. Its origin has been traced to tropical Africa. The center of diversity for the crop is in the Sahel zone of West Africa. Cultivation subsequently spread to east and southern Africa, and southern Asia.
Pearl millet is well adapted to production systems characterized by drought, low soil fertility, and high temperature. It performs well in soils with high salinity or low pH. Because of its tolerance to difficult growing conditions, it can be grown in areas where other cereal crops, such as maize or wheat, would not survive.
Today pearl millet is grown on over 260,000 km² worldwide. It accounts for approximately 50% of the total world production of millets.
Pearl millet is becoming essential to soybean production in the Cerrado region in Brazil, where it is used to conserve soil quality, and to suppress nematodes and weeds. Although originally used as a cover crop, area under cultivation is increasing rapidly and pearl millet is being grown for its quality grain and forage. In Canada, pearl millet cover or rotations are valuable to reduce soil-borne nematodes in potato cropping systems.
In the USA, this temporary summer annual grazing or hay crop is high in protein, is highly digestible, and is free of prussic acid. It is commonly used for feeding dairy and beef cattle, horses, goats, and other livestock.
Much of the grain is currently used to feed birds, particularly poultry and gamebirds for recreational hunting, such as bobwhite quail, turkey, pheasant, and dove. It is showing considerable value in poultry and egg production. When used to feed layer hens, the eggs have a higher concentration of the healthier omega-3 fatty acids. The grain is also used to feed livestock such as cattle and pigs, and is used in some specialty dog food products.
Because of its high protein content and rapid fermentation rate, the grain is showing promise as an economical feedstock for ethanol production. It is fully compatible in facilities that ferment corn or sorghum.
Pearl millet products are sold in ethnic food markets in the USA, particularly in those catering to immigrants from Africa or the Indian sub-continent where pearl millet is a familiar and traditional food. Use of this gluten-free grain in specialty food markets in the USA has been limited. Confusion over labelling in the market with other types of "millet" currently limits the development of novel food products from pearl millet.
Pearl millet grain is comparatively high in protein and has a good amino acid balance. It is high in lysine and methionine + cystine levels. It contains twice as much methionine than sorghum, an important trait for organic poultry production. The grain is also comparatively high in fat, and linolenic acid comprises 4% of the total fatty acids.
Even when grown in highly stressed conditions, the grain is essentially free of aflatoxins and fumonisins. These carcinogenic mycotoxins are a significant problem on maize when it is grown in regions where it is not well-adapted. Government policies that encourage maize production in regions where pearl millet is a traditional food may have long-term health implications among these populations.
Traditionally the mahangu is pounded with heavy pieces of wood in a 'pounding area'. The floor of the pounding area is covered with a cementlike coating made from the material of termite mounds. As a result, some sand and grit gets into the pounded mahangu, so products like oshifima are usually swallowed without chewing. After pounding, winnowing may be used to remove the chaff.
Some industrial grain processing facilities now exist, such as those operated by Namib Mills. Efforts are also being made to develop smaller scale processing using food extrusion and other methods. In a food extruder, the mahangu is milled into a paste before being forced through metal die. Products made this way include breakfast cereals, including puffed grains and porridge, pasta shapes, and "rice".
Recently more productive varieties of pearl millet have been introduced enabling farmers to increase production considerably.