Table of Contents
Harlan, J.R. 1993. Genetic resources in Africa. p.
65-65. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.
Genetic Resources in Africa
Jack R. Harlan
- LEGUMES AND OILSEEDS
- OTHER CROP RESOURCES
Indigenous African crops that have made an impact on the world scene include:
coffee (Coffea arabica), sorghum (Sorghum spp.), pearl millet
(Pennisetum glaucum), finger millet (Eleucine corocana),
watermelon (Citrullus lanatus), oil palm (Elaeis guineensis),
cowpea (Vigna sinensis), and at least some date germplasm (Pheonix
dactylifera). These crops are established in suitable regions around the
world and have their own special interest groups. They cannot be considered
new crops in any sense of the term. But, Africa has other genetic resources,
not new in a temporal sense, but new to the American experience.
First, let me call attention to some of the other cereals, both wild and tame.
Fonio or acha, Digitaria exilis (Kipp.) Stapf, has been given the
misnomer "hungry rice" by English colonials. It is not grown to relieve hunger
but because of its quality. It is a chief's food, a gourmet item, and couscous
made of fonio is better than couscous made from wheat. Tef, Eragrostis
tef Trott, is the noble grain of Ethiopia, and enjera, the bread made from
it, is the food of the upper classes. There are now Ethiopian restaurants in
the United States that are flourishing because of the demand and interest in
ethnic foods, enjera and watt (a spicy stew). These are first class foods. It
should not be difficult to develop considerable markets for them, not just
because they are ethnic and exotic, but because both fonio and tef are
genuinely superior cereals. As whole grains, they are nourishing, and enjera
is vitamin enriched by yeast from a short fermentation of the dough.
Less well known are the grains of wild cereals that were harvested on a huge
scale in the 19th and early 20th centuries. Again, the colonials, both French
and English, spoke of them in contemptuous terms ("scarcity foods,"
"céréales de disette") without ever giving them a fair trial.
Anyone reduced to eating wild grass seeds must be on the verge of starvation.
The fact is that these, too, were luxury items. They were harvested, not for
food for the harvesters, but for sale and export. The harvesters probably
reserved some seed for special occasions and ceremonies, but wild grass seeds
brought higher prices in the market than the staples, sorghum, pearl millet,
and rice, and in the Sahara, even more than wheat. The prejudice of European
colonizers closed their mind to the potential. Wild grass seeds are still
harvested, but not on the scale of a century ago (Harlan 1989a,b). It has been
suggested that a return to wild grass harvests on a substantial scale could
stop the trend toward desertification brought on by the destructive method of
livestock rearing now practiced (Vietmeyer in press).
In the desert proper, Aristida pungens Desf. and Panicum turgidum
Forsek., are the most important, the former in the north and the latter in
central and south. But, we do not expect much production from a desert. In
the Sahel and southern desert fringes, Cenchrus biflorus Roxb. is the
main grass, but it is a sandbur with spines that can torment. In the
broadleaved savanna, a group of grasses collectively called kreb(s) over a
considerable region from Mali to Kordofan in Sudan is still harvested. The
mixture varies in species composition from place to place and probably from
year to year and includes species of Panicum, Eragrostis,
Dactyloctenium, Brachiaria, and others. Panicum laetum
Kunth is one of the most common, and E. pilosa Beauv., one of the
components, is probably the progenitor of tef (Harlan 1989a,b).
Voandzeia subterranea (L.) Thouars is a legume that produces seed
underground, like a peanut, except the seeds are much larger, usually one to
the pod. A number of tests in Africa have indicated that this legume can yield
as well or better than peanuts, and it is a common experience that a crop
removed from its native territory without a normal suite of diseases and pests
can perform much better than in its homeland. The crop, sometimes called
Bambara groundnut, is actually widespread in Africa and not especially tied to
the Bambara tribe. It is more of a garden crop than a field crop and important
in subsistence agriculture, primarily in the broadleaved savannas from west
Africa to east Africa and southward to southern Africa. Realistic figures on
production are not available. A longer shot is Kerstingiella geocarpa
Harms, another "groundnut," but not nearly so widespread and probably with less
potential. It has not been especially important in Africa, and that suggests
limited value elsewhere. Still, have either of these plants been adequately
tested as a potential "new crop?" The wild forms of both species are found in
eastern Nigeria and in Cameroon.
Noog, Guizotia abyssinica Cass., Asteraceae, an oilseed crop, is the
most important edible oil in Ethiopia. It is much kinder to the grower than
safflower, lacking spines and the crop would be easy to mechanize. Extensive
trials on noog have not been conducted.
Telfairia occidentalis Hook. f., Cucurbitaceae, produces a course vine
with rather large gourd-like fruits. Oil is extracted from the seeds. It is a
garden plant of West Africa and is grown from the broadleaved savanna into the
forest zone. While we have plenty of oil seed crops, there could well be a
place for this plant in tropical subsistence agriculture outside of Africa. I
have seen it, for example, in Jamaica.
There appears to be several forms of Solanum grown for their fruits and
often lumped together as "garden eggs" by English speakers. A serious study
might reveal some potentially useful vegetables. Africa has, of course, wild
races of coffee, sorghum, the millets, rice, cotton, cowpea, cola, and
watermelon. These might have some useful genes, and wild races of most crops
are poorly collected. African rice is not likely to replace Asian rice, but
some useful genes have been found, and for Africa, at least, it has what the
French call "rusticité," or the ability to yield something no matter
what calamities it may suffer. The most useful forage grasses for tropical
pastures come from Africa, but this subject is treated elsewhere in the
Proceedings of the symposium.
Finally, attention is called to plants with medicinal potential. Herbal
medicine is well developed in Africa and intimately interlaced with witchcraft,
voodoo, and various occult arts. I can find few serious studies of either the
remedies or the witchcraft in which they are embedded. Both should be studied
as R.E. Schultes has done in Amazonia (Schultes 1990). While lacking
experience in these matters, I sense that such field studies should be done by
Africans. Who knows what potential there might be for cures or the arrest of
cancer, AIDs, or even the common cold? We have not yet investigated.
- Harlan, J. 1989. Wild grass seeds as food in the Sahara and Sub-sahara.
- Harlan, J.R. 1989. Wild grass-seed harvesting in the Sahara and Sub-sahara of
Africa, p.79-98. In: D.R. Harris and G.C. Hillman (eds.). Foraging and
farming: the evolution of plant exploitation. Unwin Hyman, London.
- Schultes, R.E. and R.F. Raffauf. 1990. The healing forest: Medicinal and
toxic plants of the Northwest Amazonia. Dioscorides Press, Portland, OR.
- Vietmeyer, N.D. The lost crops of Africa. Natl. Res. Council, Natl. Academy
Press, Wasington. DC. (in press).
Last update April 2, 1997