Sorghum, great millet
Family Gramineae (or Poaceae)
Sorghum bicolor (= Sorhum vulgare, = Holchus sorghum, = Andropogon sorghum), sorghum or great millet (S. bicolor 1), is a vigorous annual grass, up to 5 m tall, resembling maize in general appearance, but with narrower leaves. It can easily be recognised from maize by the terminal ear at the top of the stem (S. bicolor 2). The peduncle may be erect or recurved; the central axis of the panicle may be long or short, with branches bearing racemes of spikelets. The length of the axis and of the branches determines the shape of the inflorescence. The spikelets contain two florets, the lower of which is sterile.
The many varieties of sorghum not only differ in shape and structure of the inflorescence, but also in the colour of the grains, which can be white, yellow or red. Some varieties are so different that they have been described as different species.
Distribution
Sorghum is the 4th most important world cereal, following wheat, rice and maize. It is the staple food in the drier parts of the tropics and subtropics (S. bicolor 3), (S. bicolor 4). It is known as Guinea corn in West Africa, kaffir corn in South Africa, as durra in Sudan, as mtama in East Africa, as kaoliang in China, as jola, jawa and cholam in India (S. bicolor 7), and as milo and sorgo in the US.
Sorghum is probably of African origin and was taken to India during the first millennium BC. It probably reached China along the silk route. There is some evidence that the crop was known in ancient Egypt. From there it spread over the Mediterranean region. The slave trade took it from West Africa to the New World. Eventually it reached the US about the middle of the 19th century where it is grown in areas not suited for maize.
Use
Sorghum (S. bicolor 5) does not contain gluten and therefore the flour will not make good bread. In Africa the grain is ground into a flour, which is made into porridge. In Africa it is also widely used for brewing beer. The dried stems are used for thatching and fencing. Thin stems are used for making baskets and inflorescences for making brooms. The sorghum grown in the US (S. bicolor 6) is mainly grown for livestock feeding. Some short-stem varieties known as sweet sorghum are used to obtain syrup. Other varieties with a waxy endosperm are used for starch production, which is used in adhesives, for sizing paper and textiles, for gums for stamps and envelopes, and as a thickening. Oil is obtained from the embryos; it is used as cooking oil and salad oil.
Yields vary widely, depending on the location, from up to 2000 kg threshed grain per hectare in Africa and India, to up to 6000 kg in the US.