Over half a billion people rely on sorghum as a dietary mainstay and, given its diversity of uses, as an important source of income. The grain is used mainly for food, prepared in the form of flat breads and porridges of different kinds. Sorghum stover is a vital source of fodder for livestock. Sorghum is also used for a wide range of industrial purposes, including the production of sweet syrups, as a source of starch for fermentation, and for producing biofuel. The durable stalks of the plant are used by the rural poor as a construction material and as fuel for cooking.
Sorghum is an extraordinarily robust and reliable crop
- It will grow over a wide range of temperatures and elevations;
- It performs well in different soil types – from very porous sandy soils that don’t retain water to heavy clay-types that are prone to water logging;
- It has tremendous resilience in the face of drought, and not only survives but still produces grain using only residual moisture;
- It can be grown under a wider range of soil acidity than many other crops; and
- It is resistant to grain mold, giving people and animals protection against the health dangers of contamination by mycotoxins.
These attributes make sorghum a critically important food security crop for millions of people living in harsh, dry environments – places that don’t readily support crops such as maize. The cost of producing sorghum and maize are about the same, as is their nutritional value, so farmers often decide which crop to grow based on local environmental conditions. Given that sorghum requires less water, it is usually grown instead of maize in the hotter and drier areas of Africa, South Asia, and Central America.
Origins of the crop
Experts generally agree that sorghum first emerged in Northeast Africa, most likely in Ethiopia, but historical evidence that can more precisely pinpoint the crop’s center of origin is lacking. Northeast Africa is known to be a primary center of genetic diversity for the crop, and some experts believe that sorghum’s wild ancestors were first transported to India, domesticated there and then brought back to Africa. In addition, many believe that African slaves brought sorghum seeds with them to the USA, and that is how the crop was introduced to what is now one of the top sorghum-growing countries in the world (US sorghum production accounts for as much as 80% of global sorghum exports).
Where sorghum is grown today
This hardy crop is now grown on some 42 million hectares, an area only slightly smaller than all of Sweden, and is found in farmers’ fields in 98 countries spread across Africa, Asia, Oceania and the Americas. Nigeria, India, the USA, Mexico, Sudan, China and Argentina are major growers. Other sorghum-producing countries include Burkina Faso, Chad, Ethiopia, Gambia, Ghana, Mali, Mauritania, Mozambique, Niger, Senegal, Somalia, Tanzania and Yemen.
Main threats to production
Major sorghum production constraints include:
- Shoot fly, stemborer, head bug and aphid insect pests;
- Grain mold, anthracnose diseases, and leaf blight;
- Weed competition and (in Africa) the parasitic plant Striga spp.; and
- Abiotic stresses such as drought (especially terminal drought), high temperatures, acid soils (which are often associated with toxic levels of aluminum saturation) and low soil fertility (in terms of both macronutrients such as nitrogen and phosphorus, as well as micronutrients such as iron and zinc).
Current and future research
Current and on-going research by ICRISAT is aimed at increasing yield potential, disease and insect pest resistance, and tolerance to such abiotic stresses as drought, heat, and various soil-related limitations. All this research is done within the context of the Institute’s Inclusive Market-Oriented Development framework (IMOD) which seeks to harness markets for the rural poor . Looking ahead, research opportunities include:
- Creation of hybrids to increase yields for a wider range of production systems in Africa, building on successes in India, Mali and elsewhere (see Guinea-race Sorghum Hybrids);
- Development of improved “dual purpose” plant types for grain, as well as feed and fodder, that can increase the value of the crop and strengthen the integration of animal husbandry with crop production, resulting in higher and more stable incomes while improving soil health through increased organic matter cycling; and
- Efficient use of the crop’s rich genetic diversity for the improvement of sorghum and other cereals, made possible by the availability of the full genome sequence and other genetic and genomic tools that will enable identification and transfer of favorable alleles for stress tolerance (such as phosphorus deficiency, aluminum toxicity and terminal drought), product quality (micronutrient content, digestibility and industrial qualities) and superior agronomic performance.