Taming the bush mango
Sweet tasting fruit or a thickener for soups and stews, the bush mango (Irvingia gabonensis and Irvingia wombulu) can provide either depending on the variety grown. This tall, stately tree with a buttressed trunk, grows high above the canopy in primary and secondary forests in West Africa, from Senegal in the west to Cameroon in the east, and in Ghana, Nigeria, and Gabon. Most widely known for its sweet fruit (I. gabonensis), its greatest commercial potential lies in the seeds (I. wombulu) from which the kernel is extracted to make soups and stews slimy, a desirable characteristic in the region.
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| Photo credit: Roger Leakey |
According to scientists at ICRAF, there is tremendous potential for further improvement of this semi-domesticated tree. Farmers generally take naturally regenerated seedlings from the bush and plant them on their land, often close enough to the house to discourage theft of the fruits. But there is tremendous variation between trees, in quality and size of fruit, size of kernel, time to maturity and time of fruiting. Naturally, farmers are keen to have the best trees, not only for their own use but so that they can tap into the flourishing, and growing, regional trade.
Farmers have already identified some of the best trees to ICRAF scientists, who have in turn taken seed collections from these trees to form three living genebanks in the West Africa region. (The seed is recalcitrant and cannot be stored successfully in a seed genebank.) Cuttings, grafts or air-layers from the material stored in the genebank can then be taken by farmers for multiplication on their farms. This ensures that they also benefit from having trees with known properties - perhaps flowering and fruiting earlier than trees raised from seed.
Of particular interest in the selection of I. wombulu, are trees whose nuts are self-cracking, exposing the kernel and making it much easier to extract. The usual method is to crack open the hard seed coat with a machete.
ICRAF hopes that tree domestication, as part of the campaign to promote better use of trees on farm, will not only provide an additional source of nutritious food and farm income, but that it will also help to protect from over-exploitation the trees that remain in the wild.
