Sorghum (Revised)

General Information and Agronomic Aspects

Introduction

Sorghum bicolor is an annual plant that belongs to the family Poaceae (grasses) and the genus Sorghum.

The Sorghum genus is highly diverse with around 20–30 species. Among them, only Sorghum bicolor (L.) Moench is cultivated, while the others are wild or weedy.

Sorghum bicolor is believed to have originated in northeastern Africa, specifically in regions around the Nile River. It has a long history of cultivation and use by various African civilizations, dating back thousands of years. In Africa, a major growing area of sorghum runs across West Africa south of the Sahara almost to the coast and eastward into Sudan, Ethiopia, and Somalia. It is grown in upper Egypt but is a minor crop along the north African coast. It is commonly grown in Uganda, Kenya, Tanzania, Rwanda, and Burundi and fairly important in Zambia, Malawi, and drier areas of Mozambique. It is important in Botswana and Lesotho and common in South Africa, and minor in Namibia.
Sorghum is perhaps the world's most versatile crop. Some types are boiled like rice, some cracked like oats for porridge, some "malted" like barley for beer, some baked like wheat into flatbreads, and some popped like popcorn for snacks. A few types have sugary grains and are boiled in the green stage like sweet corn. The whole plant is often used as forage, hay, or silage. The stems of some types are used for building, fencing, weaving, broom making, and firewood. The stems of other types yield sugar, syrup, and even liquid fuels for powering vehicles or cooking meals. The living plants are used for windbreaks, for cover crops, and for staking yams and other heavy climbers. The seeds are fed to poultry, cattle, and swine. It can survive drought conditions for some weeks by rolling up its leaves and thus decreasing transpiration. 
Sorghum is the world's fifth most important cereal, following wheat, rice, maize, and barley. Global production ranges from 55 to 70 million tons annually, spread across 40 to 45 million hectares. Key producers include the United States, India, China, Mexico, Nigeria and Sudan. Sorghum is grown for commercial purposes in the United States, North and South Africa and India, and it is also established in South America and Australia for both grain and fodder. While production varies due to factors like rainfall, sorghum continues to play a significant economic role, although its trade is limited, with most of it consumed by producers and minimal amounts entering the cash economy for sale.
(Grubben & El Tahir, 2004, National Research Council, 1996)
Please also check KARI update: "Sorghum helps provide better food security", July 1997, available in English on http://www.kari.org/ENGLISH/Sorghumfood.htm (click to follow link)

Species account

Sorghum bicolor is a strong annual or perennial grass cultivated for its grain. Culms (stems) usually 1-2 m high, often with prop roots at the lowest nodes. Leaves: Leaf-blade broader than in pearl millet. Flowers: Inflorescence a large terminal branched panicle which may be compact or loosely held. Fruits: Grain of various colors ranging from white to red and dark brown. Many varieties are known, some only found and maintained locally by individual communities and deeply integrated into their culture. (Maundu, P. et al., 1999).

Sorghum varieties
Sorghum bicolor is one of the most variable species. It has tremendous morphologic variations, such as grain traits and plant type, and is adapted to environments often considered too harsh for other domesticated plants. The variation is also reflected in seed size. These variations may be partly attributed to the widespread coexistence with its wild relatives in the center of origin. 

This variety is a source of malt, but can also be used for ugali. It does well in low and to medium altitudes

Ecological conditions

Sorghum is adapted to a wide range of environmental conditions and will produce significant yields under conditions that are unfavourable for most other cereals. Sorghum is particularly adapted to drought. 
Sorghum also tolerates water logging and can be grown in areas of high rainfall. It is, however, primarily a plant of hot, semi-arid tropical environments with rainfall from 250 mm that are too dry for maize but performs best with more than 900 mm annually. It is also grown widely in temperate regions and at altitudes of up to 2500 m in the tropics. Sorghum tolerates a wide range of temperatures. Sterility can occur when night temperatures fall below 12-15°C during the flowering period. Sorghum is killed by frost. 

Sorghum can be grown successfully on a wide range of soil types. It is well suited to heavy clay soils (vertisols) found commonly in the tropics, where its tolerance to water logging is often required, but is equally suited to light sandy soils. It tolerates a range of soil pH from 5.0-8.5 and is more tolerant to salinity than maize. It is adapted to poor soils and can produce grain on soils where many other crops would fail. 

Agronomic aspects

Sorghum is normally grown from seed. A fine seed-bed is preferable but is often not achieved. The seed is usually sown directly into a furrow after ploughing, but can also be broadcast and harrowed into the soil. Optimum plant spacing depends on soil type and availability of moisture.

For favourable conditions, row spacing of 45-60 cm and plant-to-plant spacing of 12-20 cm, giving populations of about 120 000 plants per ha, are normal. For drier or less fertile conditions, wider spacing and lower plant populations are usually optimal. The seed rate varies from 3 kg/ha in very dry areas to 10-15 kg/ha under irrigation. Occasionally, seedlings are grown in a nursery and transplanted into the field early in the dry season, e.g. on the flood plains round Lake Chad in Africa.

Husbandry

Sorghum is usually grown as a rainfed crop, sown after the onset of the monsoon season. Seeding rates are often higher than optimum to compensate for poor seed-bed or to allow for unfavourable moisture conditions. All sorghum varieties require a fine seed bed for better seedling establishment. If tractor or oxen are used to open up a shamba, it is advisable to harrow after the first ploughing. When jembes (hoes) are used for land preparation, farmers are advised to ensure that large clods are reduced by breaking them to provide a smooth seed bed. The planting field should be prepared well in advance of sowing. Seed rate is 7-10 kg/ ha or 3-4 kg/acre. Dry planting is highly recommended. Thus plant before or at the onset of rains by either drilling in the furrows made by tractor or oxen plough, or hill plant in the holes made by jembe or panga. When dry planted, planting depth should be 5 cm but when planting in a moist soil use planting depth of 2.5-4 cm. Common row spacing is 75 cm and distance between plants about 20 cm. In semi arid areas where the ox plough yoke is fixed at 90 cm especially in Machakos, Makueni, Kitui and Mwingi districts, the recommended spacing between plants is 15 cm. 

Subsistence farmers rarely apply fertiliser, as responses depend on moisture availability, which is usually very uncertain. Under more favourable conditions, farmyard manure is used with advantage, but even so the quantities used are usually below optimum. Optimally sorghum needs the availability of about 20 kg N/ha and 20 kg P/ha at planting time, which can be supplied by alternate cropping with legumes and application of compost or manure. Also intercropping with legumes is recommended with grain legumes such as beans, cowpeas, pigeon peas and green gram. Manure and compost improve organic matter content of the soil, soil moisture retention ability and soil structure. Manure can be broad cast in the field or applied in planting furrows and mixed with soil before seeds are planted. The standard farm wheelbarrow when full holds approximately 25 kg of dry manure/compost. At a low rate, two wheel barrows are enough for a 10 m by 10 m area. This translates into 200 wheelbarrows or 5 tons/ha. When aiming for high rate apply 400 wheelbarrows or 10 tons per ha. 

The crop is usually weeded by a combination of inter-row cultivation with animal-drawn implements and hand weeding within rows. Thinning is carried out at the same time as hand weeding, or at intervals during the crop cycle, particularly where thinnings are used to feed livestock. Gapping by transplanting thinnings is encouraged when thinning is done within 2 weeks after emergence and when the soil is moist. 
Sorghum ratooning

Ratooning is a practice of getting more than one harvest from a single sowing. Two ratooning systems have been identified. One in the bimodal rainfall zones in semi arid lowlands giving 2 crops and the other in the moist mid altitude coffee zones where the local varieties are the two seasons ratooning type. A ratoon crop compared to a newly sown crop has an established root system which will utilizs the available water in the root zone for crop growth early in the season, reduce ploughing and planting labour and avoid migratory quelea birds in August by maturing early. 

In bimodal rainfall zones of semi-arid lowlands in Eastern province sorghum is planted in short rains (October- November). When the crop is mature, it is harvested in February and immediately ratooned to take advantage of the long rain season which starts in mid-March. To achieve good yields, the crop is thinned to 2-3 tillers per hill. Weeding and other management practices are done as for a newly sown crop. 

Production zones in Kenya and recommended sorghum varieties and their major characteristics: 

Eco-zone and area	Variety	Maturity months	Grain colour	Yield potential  (90 kg bags/acre)	Special attributes
Moist-mid-altitude  Busia, Siaya, Kakamega, Kisumu, Homabay, Kuria, Migori,  Coffee zones of Meru, Embu and Nyeri Districts	"Serena"  "Serodo"  "KARI/Mtama1"	3.0  3.5  3-3.5	Brown  Brown  White	12  12  15	Wide adaptability Tolerant to striga Wide adaptability Tolerant to stem borers. Attractive to birds
Semi-arid low lands  Machachos, Kitui, Makueni, Mwingi, Lower Embu and Tharaka Nithi,  Kajiado, Parts of Rift Valley, Parts of North Eastern Provinces	"IS76"  "KARI/Mtama1"  "KARI/Mtama2" "Gadam" "Serena" "Serodo"	3  3-3.5 3.5 3.5 3 3.5	White  White  White  Greyish Brown Brown	10  15 15 8-20 12 12	-  Tolerant to stem borers. Attractive to birds Resistant to birds Tolerant to stem borers, shoot fly and foliar diseases Wide adaptability. Tolerant to striga Wide adaptability
Cold semi-arid Highlands  Nakuru, Baringo, Laikipia, Naivasha, Narok,  Parts of Koibatek, Taita Taveta	"E 1291"  "E 6518" "BJ28"	7  8 7	Brown  Brown Brown	12  15 12	Dual purpose. Good beverage quality Dual purpose. Good beverage quality Dual purpose
Humid Coast  Lamu, Kilifi, Taita Taveta, Kwale, Mombasa	"Serena"  "Serodo" "KARI/Mtama1" "Gadam"	3  3.5 3  3	Brown  Brown White Greyish	12  12 15 8-20	Wide adaptability Wide adaptability Tolerant to stem borers. Attractive to birds Tolerant to stem borers, shoot fly and foliar diseases

 

Examples of some sorghum varieties grown in Uganda

• "Epuripur": This is a white seeded variety, resistant to shoot fly and stem borers but susceptible to bird damage. It yields about 2.5 - 3.0 tons per ha. Grains are sweet and can be used for food, baking and brewing.
• "Sekedo": It is a dwarf variety (100 cm) with brown-red seeds. It is tolerant to stem borers and moderately resistant to shoot fly. It is recommended for food and feeds. It matures in 100 days with a yield potential of 4 - 5 tons per ha
• "Seredo" (variety characteristics as in Kenya).
• "Serena" (variety characteristics as in Kenya).

Examples of some sorghum varieties grown in Tanzania for regions Dodoma, Mwanza, Shinyaga, and Singida

• "Seredo" (variety characteristics as in Kenya).
• "Serena" (variety characteristics as in Kenya).
• "Macia" ("SDS 3220") white grain; early maturing (80 days); yield potential 4t/ha
• "Pato" ("SDS 2293-6") grain colour cream/yellow white mottled; early maturing (80 days); yield potential 4 t/ha.
• "Tengemeo" ("2KX17/B/1") grain colour creamy white; early maturing (80 days); very good drought resistant; attractive to birds; resistant to major diseases and insect pests; good brewing quality; good storage; yield potential 4 t/ha.
• "Lugugu" (Landrace; white grain).
• "Udo Msonga" (Landrace; brown grain).
• "Msumbji" ("IS7173") (Landrace; high aluminium tolerance).
• "PN3" white grain; high grain yield (4 t/ha); good storage; very good brewing quality; insect and disease reaction poor; poor bird resistance.

Harvest, post-harvest practices and markets

Harvest

Sorghum is usually harvested by hand when it has reached physiological maturity - which means the grain is hard and does not produce milk when crushed. Cut the heads with sickles or a sharp knife from plants in the field or cut the whole plant and remove the heads later. Sun dry the harvested panicles to a moisture level of 12-13 % and thresh and store the grain. For further information on storage, please also refer to datasheets on grains and legumes e.g. green gram click to follow link

Post-harvest practices
After harvest, sorghum is sun-dried, and in some cases, the panicles are hung over kitchen fires to repel insects. Alternatively, the grain heads can be dried and then threshed. Traditional methods involve manually beating or pounding well-dried sorghum panicles to separate the grain, while mechanical threshing machines are used for larger-scale operations. After separation, winnowing eliminates any remaining chaff or debris, and the cleaned grains are stored in insect-resistant granaries, which can be located either above or below ground.
Traditional sorghum food preparation methods vary. The whole grain can be ground into flour or decorticated before grinding into fine particles or flour. For porridge, sorghum flour is slowly added to boiling water until the desired consistency is achieved, requiring regular stirring. Another method is to boil the grain before or after decorticating. To make sorghum beer, grain is germinated, dried, ground into flour, mixed with water, and left to ferment. For the non-fermented drink 'mageu' in Botswana and South Africa, sorghum malt is mixed with water and left at room temperature for 2-3 days with occasional stirring. Forage sorghum can be fed to livestock while still green or can be stored in various ways for later use. The forage is often dried and stacked or can be made into silage. Stover left after harvest of grain is often grazed by animals.
(Balole, T.V. & Legwaila, G.M., 2006, PROSEA, 2016) 

Markets 
Sorghum grain ranks fifth among the world's major cereals, following wheat, rice, maize, and barley. Global production ranges from 55 to 70 million tons annually, cultivated on 40 to 45 million hectares. Since sorghum is primarily grown in dryland and marginal environments, its productivity and cultivated areas fluctuate significantly due to variations in rainfall. Therefore, one should exercise caution when considering average statistics. The leading sorghum producers include the United States (25%), India (21.5%), Mexico (11%), China (9%) and Nigeria (almost 7%). Together these five countries account for 73 percent of total world production. Global sorghum trade is limited, as most of it is consumed by local producers, with minimal entry into the commercial market.
(PROSEA, 2016, FAO, n.d)

Nutritional value

Sorghum is an underrated, low fat and nutrient-dense cereal grain with a wide range of uses. It is an excellent source of energy, providing approximately 336 calories per 100 grams of cooked sorghum. The bulk of its composition is carbohydrates, mainly complex carbohydrates, which are slow-digesting and provide a sustained source of energy. This makes sorghum a low glycemic index (GI) food, making it suitable for individuals managing diabetes.
Furthermore, sorghum is rich in dietary fiber, aiding digestion and promoting regular bowel movements. Dietary fiber also contributes to a feeling of fullness, which can be beneficial for weight management. Sorghum contains a moderate amount of protein, making it a valuable protein source, especially in regions where animal protein is less available. Sorghum is also a good source of essential vitamins and minerals. It contains B vitamins like niacin (B3), riboflavin (B2), and thiamine (B1), which are crucial for energy metabolism and overall health. Moreover, sorghum contains essential minerals like Phosphorus, Magnesium, Iron, and Potassium, all of which play pivotal roles in bone health, muscle function, and blood circulation.
Furthermore, sorghum boasts antioxidants like phenolic acids, tannins and flavonoids. These antioxidants protect cells from oxidative damage and may help reduce the risk of chronic diseases. Moving on to its health benefits, sorghum has several noteworthy advantages. Firstly, it is naturally gluten-free, making it an ideal choice for individuals with celiac disease or gluten sensitivity.
Sorghum also contributes to heart health by lowering cholesterol levels and reducing the risk of heart disease, thanks to its fiber content and antioxidant properties. Its low glycemic index can help stabilize blood sugar levels, making it suitable for those managing diabetes. The fiber in sorghum promotes digestive health by preventing constipation and maintaining a healthy gut microbiome.
(Healthline n,d, webmd, n.d)
Further reading:
•    https://www.healthline.com/nutrition/sorghum
•    https://www.webmd.com/diet/health-benefits-sorghum
Table 1: Proximate nutritional  value per 100g edible portion.

Source (Nutrient data): FAO/Government of Kenya. 2018. Kenya Food Composition Tables. Nairobi, 254 pp. http://www.fao.org/3/I9120EN/i9120en.pdf

RE=retinol equivalents.

RAE =Retinol activity equivalents. A RAE is defined as 1μg all-trans-retinol, 12μg beta-carotene, or 24μg α-carotene or β-cryptoxanthin.

^a Lewis, J. 2019. Codex nutrient reference values. Rome. FAO and WHO

^b NHS (refers to saturated fat)

^c https://www.hsph.harvard.edu/nutritionsource/water/

^d British Heart Foundation

^e FDA

^f NIH

^g Mayo Clinic

Nutritive Value per 100 g of edible Portion

*Percent Daily Values (DV) are based on a 2000 calorie diet. Your daily values may be higher or lower, depending on your calorie needs. 

Recipes

1. Ngima ya muvya (Sorghum ugali)
(Kamba, Kitui, Kenya)

Ingredients
    1 Kg Muvya (sorghum)
    Ghee (optional)
Method
    Pound sorghum in a mortar using a pestle. Use a little water for pounding
    Dry the pounded sorghum in the sun for 30 minutes
    Winnow using a tray (uteo) to remove chaff
    Mill the sorghum coarsely (using a miller or traditional stone) 
    Sieve using a wide mesh to separate the bigger particles (nzenga) from the fine flour 
    Cook the bigger particles first then add the fine flour little by little while stirring vigorously to ugali
    Add ghee if available and stir
    Serve warm with sour milk or vegetable
    Provides 5 servings
(Source: Kyanika Adult Women Group, Kitui, 2005)

2. Mungamano wa Muvya (Sorghum-bean mixture)
(Kamba, Kitui, Kenya)
Ingredients
    ½ Kg Sorghum
    ½ Kg dry beans
    3 tablespoons ghee 

Method
    Pound sorghum to remove outer seed covering
    Winnow to remove the chaff
    Boil the beans till cooked
    Wash the pounded sorghum and add to boiling beans
    Stir and cook further till the sorghum is ready.
    Season to taste
    Remove from heat source after it has cooked well
    Add ghee, stir and serve warm
    Can also be fried onions and tomatoes
(Source: Kyanika Adult Women Group, Kitui, 2005)

3. Muvya na Nzooko (Sorghum with cowpea)
(Kamba, Kitui, Kenya)

Ingredients
    3 kg of sorghum grains
    Cowpea seeds 1 kg 

Method
    Pound the sorghum lightly in a mortar to remove unnecessary covers 
    Winnow to remove chaff
    Boil cleaned cowpeas first for about 30 minutes
    When almost cooked, wash sorghum and add on top
    Cover to cook, do not stir
    Put just enough heat
    Cook for one hour
    If there is more water left drain it
    Add ghee on top 
    Add salt to taste
    Stir well and remove
    Serve with juice or as it is
(Source: Kyanika Adult Women Group, Kitui, 2005)

4. Atapa (ugali)
(Teso, Busia, Kenya)
Ingredients
3 cups of water 
Mixed flour (millet, sorghum & cassava- One part of each to make 5 cups of flour)

Preparation
Mix millet, sorghum and cassava flour evenly
Boil water in a pot 
Add the flour little by little, stirring continuously until the mixture stiffens desirably such that there are no flour lumps visible
Lower the heat and cook for 30 minutes. During this time turn it thrice to ensure that the ugali does not burn at the bottom of the pot.
Mould the ugali to a round shape.
Remove from the fire and place on a plate or tray. 
Dip the wooden spoon in warm water and mould the ugali well to a round shape
Serve with vegetables

Remarks
In the preparation of ugali, 1 cup of water makes ugali for one grown-up. Water quantities can thus be adjusted to suit the number of individuals.
Source: Ruth Adeka and P. Maundu, 2005.