Sorghum farming is an important agricultural activity in Kenya. Sorghum is grown in western, northern Rift Valley, eastern and some parts of Central Province. The crop is fairly drought resistant and thus it is quite popular in drier areas of the Kenya. It is also resistant to water logging and yields reasonably well on infertile soils. It can be rationed.
Sorghum grains are ground for flour, which is used for making porridge, ugali or for brewing. Young growing crop may be used as fodder by feeding it to animals directly after wilting for sometime or making silage.
Ecological Requirements for sorghum farming in Kenya
Sorghum has a well developed rooting system and an ability to roll up its leaves during hot weather. These qualities make the crop drought resistant. Rainfall of 420 mm — 630 mm per annum is adequate for good growth and production, hence the crop grows well in areas below 1500 m above sea level. At higher altitudes, poor yields are obtained and the crop is attacked by pests such as shoot fly and downy mildew disease. The crop requires fairly fertile and well drained soils.
Sorghum Varieties in Kenya
Sorghum varieties are characterised by seed colour and taste. In this connection, there are varieties which are white in colour and palatable and those that are brown or red and are bitter. There are two notably improved varieties grown in Kenya, these are:
This variety was selected in western Kenya and is suitable for all the areas around the shores of Lake Victoria. Its seeds are brown and matures in about four months.
This variety was selected after crossing dobbs with a variety from Swaziland. It has brown seeds and matures in about 3% months. There are other varieties being developed by Research Stations. The research is based on characteristics such as taste, disease and pest resistance and yields. Varieties with compact panicles and goose neck have some resistance to birds’ damage.
Selection and Preparation of Sorghum Planting Materials
The seeds are prepared by threshing the dry heads, winnowing and seed-dressing.
Planting is normally done by broadcasting the seeds on the firmly prepared seedbed. Sorghum is usually sown together with other crops especially maize and beans. It can also be planted in pure stands at a spacing of 60 cm — 15 cm.
(b) Fertiliser application
Fertilisers are not commonly used in growing sorghum, however it responds well to farm-yard manure on moist soils.
Pests and Disease Control
Birds are the main cause of crop loss in sorghum. The most devastating species is the Sudan Dioch (Quelea Quelea aethiopica). Other birds that eat sorghum are weavers, starling and bishop’s birds. Sorghum has natural quality which keep birds away, such as persistent bitter tasting coats, found in coloured grains. Goose necked varieties are slightly resistant to birds attak. The Ministry of Agriculture has a quelea control unit, which kills large numbers of birds using ﬂame throwers, explosives or poison sprays in their breeding colonies.
(ii) Sorghum shoot ﬂy (Antherigona varia)
The adult ﬂy lays eggs on the underside of very young plants. After hatching, the young larvae enters the funnel and moves down to feed on the young stem, killing the young shoot. Several tillers appear but they may also be attacked. Control is mostly done by early planting, closed season and application of insecticides.
(iii) Stem borers (Busseolafusca)
There are three main species of stem borers which attack sorghum. Busseolafmca, the common maize stalk borer is easy to control because it feeds in the funnels, before moving down to feed on developing tissues.
Application of insecticides kills it. Chilo zonellus is difﬁcult to control because it has no distinct population peaks. Young plants may be attacked any time. Sesamia calamistis bores holes straight into the centre of the stem. Attacks occur only occasionally.
Stem borers are controlled by use of insecticides and proper disposal of crop remains after harvesting.
Sorghum is attacked by both leaf and inﬂorescence diseases. Some of the most important leaf diseases include:
- Leaf blight (Helminthosporium turcicum)
- Anthracnose (Collezotrichum graminicola)
- Sooty stripe (Ramulispora sorghi)
Diseases of the inﬂorescence include the following:
- Loose smut (Sphacelozheca cruenta)
- Head smut (Sphacelotheca reiliana)
Leaf diseases are effectively controlled by growing improved varieties which show varietal resistance. Smuts are controlled by seed dressing.
Sorghum is ready for harvesting, three to four months after planting. The heads are cut off using a sharp knife, after which they are sun dried. The dried sorghum is then threshed, winnowed and stored.
The yields range from 500-1500 kg per hectare but with good husbandry yields of 3000 kg per hectare could be achieved. Sorghum can be rationed for one or two seasons.
The crop is marketed through the National Cereals and Produce Board.Private buyers also purchase sorghum directly from farmers.