The genus of Sorghum is found in warm, dry climates, especially in Africa, India, Pakistan, China and the Southern USA where its members are grown as important grain or forage crops. Because sorghums have been in cultivation for a long time and because interspecific hybrids are easily formed, the taxonomy of the genus is somewhat confused.
Until recently the cultivated types were loosely grouped together in the species Sorghum vulgare, but a thorough revision of taxonomic relationships suggests that Sorghum bicolor is the species to which the grain crops should belong.
The seed of grain sorghum or dura as it is often called, contains no gluten, and hence is by itself not suitable for bread making. Normally for human consumption the grain is group into flour, mixed with water or fat and cooked to form a porridge or batter.
Alternatively, the grain is fed to pigs or poultry, its starch may be used for a variety of purposes such as an adhesive or for sizing or it may be fermented to produce alcohol. Sorghum are also grown as forage crops and may produce high yields of the order of 30,000 kg/ha from several cuts throughout the year.
Best resulted are obtained from special forage types such as sorgo, sweet or sugar sorghum which is variously described as a variety of sorghum or as a separate species (Sorghum saccharatum). Sudan grass (S. Sudanese), a tall and tufted tropical grass, is often used top produce hybrids with sorghum, as for example the production forage plants Sudax or Sordan.
One possible problem with these forages is that contained in the leaves there may be a cyanogenic glycoside, dhurrin, which when eaten by animals hydrolyses to form poisonous hydrogen cyanide.
In ruminants, hydrogen cyanide is rapidly detoxified in the rumen and liver by reaction with sulphide or cystine, but the danger of toxicity remains of glycoside levels are high or sulphur intake is low. The problem can be avoided by the choice of safe cultivars by not allowing stock to graze very immature growth, or by feeding as hay or silage.
Sorghum
