What is Sorghum?
The Origin and History of Sorghum
The origin of sorghum is generally believed to be around the present day Ethiopia. Many authors now regard Ethiopian highlands as a primary centre of domestication. Sorghum is the 5th important cereal after wheat, rice and maize. It's a staple food crop for arid and semiarid areas of the world. Sorghum is also commonly referred to as kafir corn, milo, sorgos, durra and guinea millet.
From Ethiopia sorghum was taken to West Africa across the Sudan from where it was first grown among the Mande people of the upper Niger. Also from Ethiopia, sorghum was taken to east Africa from where it was distributed among the Nilotic and Bantu people. Sorghum was taken from East Africa to India during the first millennium from where it was taken to China in the early Christian era. Sorghum races in India are closely related to those in northeast Africa. From West Africa, sorghum was distributed to USA and other parts of the world through slave trade around mid 19th Century. Before 1900 full-scale cultivation of sorghum had started in the southern great plains of the USA.
Sorghum is an erect cereal plant that grows to a height of 0.5m-4.5m depending on the type of cultivar. Sorghum belongs to the sub family of Panicoideae and tribe and ropogoneae. Two sub-species of sorghum are generally recognized thus sorghum bicolor which represents all the cultivated forms and wild sorghums, and grass sorghums which are either perennial weeds or grown as forage.
Sorghum is used for food, fodder, and the production of alcoholic beverages. It is drought tolerant and heat tolerant and is especially important in arid regions. It is an important food crop in Africa, Central America, and South Asia, and is the "fifth most important cereal crop grown in the world" African slaves, introduced sorghum into the United States of America, where most of the world's commercially grown sorghum is now produced, in the early 17th century.
Sorghum is perfectly safe and is suitable for people of all ages and especially for people that are lactose tolerant. Sorghum is a whole food and can be eaten for breakfast, lunch and supper.
According to Purseglove (1988) there are 5 different types of sorghum:
1. Grain sorghum which is grown for grain
2. Sorgos grown mainly for fodder, hay and silage
3. Grass Sorghum is wild sorghum e.g. Sudan grass
4. Broom corn sorghum used for making brooms
5. Waxy Sorghum has waxy endosperm and is used for starch manufacture
Of all the major crops sorghum is the only crop that is not genetically modified, for higher yields or resistance to land borne disease.
Sorghum can grow in a wide range of ecological conditions and can still yield well even under unfavourable conditions of drought stress and high temperatures. It is generally grown between 40 degrees North and 40 degrees south of the equator, in warm and hot countries characteristic of the semiarid environment. Sorghum is usually grown in areas that are too hot and dry for maize.
The ability of sorghum to grow in drier environments is due to a number of physiological and morphological characteristics;
• Produces many roots compared to other cereals
• Has reduced leaf area thus reducing water loss through transpiration
• Can remain dormant during drought and resume growth when conditions are favourable
• Above ground parts of plant grow only after the root system is well established
• The leaves have a waxy coating and have the ability to roll in during drought thus effectively reducing transpiration
• Competes favourably with most weeds
• Has higher net photosynthesis compared to other cereals
Sorghum also tolerates a wide range of soil conditions. It does well both in fertile valley bottom soils as well as in nutrient poor soils. However, under dry land conditions, dry soils retard uptake of nutrients.
Also, soil water, soil physical resistance and soil porosity affect growth and distribution of sorghum roots.
Sorghum is a short day plant and different cultivars vary in their sensitivity to the photoperiod. Sensitivity to the photoperiod is a genetically controlled character, which can be bred or selected for. In West Africa, informal selection by farmers for day length sensitivity in sorghum resulted in crops that mature as the available water is exhausted in the early part of the dry season. This ensures that the crop fully utilizes the growing season while avoiding diseases associated with high humidity during grain maturation.