Fonio (Digitaria exilis Stapf) is an annual tropical grass grown in West Africa for its starch-rich, tiny seeds. In this region, fonio grain plays a major role in food security, preventing food shortages as it ripens outstandingly faster than other crops and can be harvested one month before other cereals like maize or millet. Fonio grain is a high quality cereal, with a particularly good nutty taste, and a favourable amino acid profile (Vodouhè et al., 2006; NRC, 1996). An important trait of fonio is its resistance to drought and its adaptation to climate change (Cruz et al., 2016). Fonio grain, once dehulled and polished to removed the hulls and bran, is primarily used for food rather than for feed though it can be very valuable for monogastric animals (Clottey et al., 2006). Fonio straw and chaff provide forage for ruminants (see the Fonio forage datasheet).
Morphology
Fonio is an ascending, free-tillering annual cereal grass. It has slender, kneed stems growing up to 80 cm in height. The leaves are alternate, simple. The leaf blade is glabrous, linear to lanceolate in shape, 5–15 cm long × 0.3–0.9 cm broad. The inflorescence, a terminal digitate panicle, bears 2–5 slender, spike-like racemes, up to 15 cm long. The spikelet is stalked, narrowly ellipsoid, surrounded by lemma, palea, and glumes. The fruit is a minute caryopsis (grain), oblong to globose-ellipsoid in shape, about 0.5 mm long, white to pale brown or purplish in colour (Vodouhè et al., 2006). The 1000-grain weight is only about 0.5 g, making fonio the smallest cereal grain worldwide (Jideani et al., 1993).
Uses
Fonio is a staple food but also a gourmet and prestige food ("chief's food"). It is used to make special couscous types in the Hausa parts of Nigeria, Benin, Togo and Ghana. It is cooked with beans to prepare a dish for special occasions in southern Togo. In Nigeria, fonio grain is milled to yield a flour that is used for porridges (thick, unfermented porridge named "tuwo acha", and thin, fermented porridges: "kunu acha") or for bread, in mixture with other flours. Boiled whole grains can be cooked with vegetables, fish or meat to make what is called "fat fonio" in Guinea, Mali and Burkina Faso. Fonio grain can be fermented to prepare the beer "tchapalo" (Cruz et al., 2016). Fonio production and consumption are highly linked to the social and cultural lives of the populations. In Mali, Dogon cosmology refers to fonio as the original atom of the universe. In the Dominican Republic, fonio is used in religious festivities inherited from African slaves. Many ethnomedicinal properties are attributed to this grain (Vodouhè et al., 2006; Adoukonou-Sagbadja et al., 2006).
It must be noted that fonio harvest and particularly its post-harvest operations are traditionally done manually and are extremely tedious and time-consuming, leading many observers to consider that these issues are a major bottleneck in the processing and utilization of fonio (Philip et al., 2006; Cruz et al., 2016). In fonio-producing regions of Togo, for instance, it was reported in 2006 that younger generations of farmers were less and less taking an interest in this grain due to the tediousness of its processing (Adoukonou-Sagbadja et al., 2006).
While primarily used for food, fonio grain could be a valuable feed for farm animals due to its high energy et methionine content (NRC, 1996). Its use has been noted in Togo for poultry feeding (Adoukonou-Sagbadja et al., 2006).