With this enormous range of plant types it may be misleading to make generalised
statements about “sorghum”. The information given below is only a brief guide and
further reading is needed to fully understand the complexity of this crop.
Nevertheless there are some characteristics of the sorghums that are almost
always found in common, listed below:
Drought resistance: sorghum has been called the “camel of the plant
kingdom”, though in fact most millets are more drought resistant than most
sorghums. Sorghum needs much less water than maize, though young maize
plants can be equally drought resistant as sorghum plants of the same age. The
plant has certain features that enable it to survive drought, such as its ability to
remain dormant during dry periods, and then recover.
Adaptability: sorghums can be found which will grow on a wide range of soils
and rainfall.
Intolerance of cold: virtually all of the sorghums are killed by frost.
Preparation for food: sorghum grain is prepared for eating in many ways like
maize, which it closely resembles both botanically and nutritionally.
Damage by birds: in 1967 it was estimated that the loss of food that year alone
in the Sudan area caused by the Weaver bird (Quelea spp.) was 4 million MT.
These birds, and others, can make devastating attacks on sorghum, unlike
maize, which protects its seed inside a cob.
Pollination: sorghum is mainly self-pollinated, although about 6% cross-
pollination can occur, depending on the variety, growing conditions and
compactness of the inflorescence.PLANTING
Soil: sorghum plants adapt to a wide range of soils; deep, fertile sandy loams are
best, with pH 5–8.5. Tolerates slightly saline and alkaline soils; intermediate
tolerance to acid soils. Better adapted to heavy soils than pearl (bulrush) millet.
nutrients which is the main limiting factor to plant growth. In less arid regions
fertiliser usually gives an economic response, Nitrogen being the most beneficial.
Sensitive to iron deficiency, symptomised by chlorosis.
Seed rate: not very critical, as sorghum plants compensate quite well by producing
fewer or more tillers, and so adjusting to different plant populations. A rough and
ready rule of thumb is to plant 1 kg/ha for every 70 kg/ha of the “normal” yield
expected.
Average figures are 2–5 kg/ha in dry conditions, 5–10 kg/ha in medium moisture
conditions and 10–20 kg/ha in moist or irrigated soil. There are between about
25,000 and 70,000 seeds per kg.
Spacing: the seed is very often broadcast, but when planted in rows these are about
60-90 cm apart, with 20–60 cm between plants.
Depth: 2–3 cm in moist soil, 4–5 cm in dry soil.
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Poor response to fertiliser in dry conditions, where it is usually water and not