Digitaria exilis

Cultivation Details

Fonio is grown at sea level in Gambia, Guinea-Bissau and Sierra Leone, but more often it is cultivated at elevations of 600 - 1,500 metres^[1]. The average temperature in the growing season ranges from 20°c at higher altitudes to 25 - 30°c near sea level^[1]. Fonio is grown in areas with an average annual rainfall of 150 - 3,000 mm, but its cultivation is concentrated in regions with an average annual rainfall of 900 - 1,000 mm^[1]. The plant is not as drought resistant as pearl millet, but fast-maturing landraces are suited to areas with short and unreliable rains. In areas with very low rainfall it is grown in valleys benefiting from run-off water^[1]. Fonio can be grown on poor, shallow, sandy or rocky soils unsuitable for other cereals, but does not prosper in saline or heavy soils. On the Fouta Djallon Plateau of Guinea, it grows on acidic soils with very high aluminium contents^[1]. Flowering usually occurs 6 - 8 weeks after the seedlings emerge^[1]. The time from sowing to maturity is normally 2 - 5 months, though certain landraces mature so quickly that they produce grain just 6 - 8 weeks after planting, long before any other cereals, and so they provide food early in the growing season^[1]. At maturity the stems bend down due to the weight of the grains^[1]. Grain yields of fonio are normally 600 - 900 kg/ha, but yields of over 1000 kg/ha have been recorded. In marginal areas yields may be as low as 150 - 200 kg/ha^[1]. Fonio is usually cut with a knife or sickle, tied into sheaves, dried and stored under cover. Mechanization is difficult because of lodging^[1]. When plants are dry, the grain shatters easily, and therefore it is better to harvest before the dry season has fully established and the relative air humidity has considerably declined. Harvesting is often staggered, to suit the immediate needs of the farmer^[1]. The plant may have derived in cultivation from Digitaria longiflora^[1].