Exploiting the potential of indigenous agroforestry trees:: Parkia biglobosa and Vitellaria paradoxa in sub-Saharan Africa

Parkia biglobosa (nere) and Vitellaria paradoxa (karite) are indigenous tree species that are economically and socially important for local people in sub-Saharan Africa. Farmers deliberately maintain these trees on farms mainly for their fruits and nuts. The kernels of karite yield shea butter, which is rich in fatty acids; it is used locally for food and internationally in chocolate, pharmaceutical and cosmetic products. Nere seeds are ground into a pungent nutritious spice or condiment, soumbala or dawadawa, which is added to soups and stews throughout the savanna regions of sub-Saharan Africa. The tree is also important in improving soil fertility and in traditional medicine. Despite their important uses, the populations of both species are in decline and they remain semi- or undomesticated. Recent research has shown that both species are genetically diverse, which indicates their potential for domestication through selection and breeding, and that crop production under the trees could be improved by crown pruning. Research also has helped develop vegetative propagation methods that allow multiplication of superior trees and on-farm domestication of the trees. Domestication should enhance their role in improving rural livelihoods. New knowledge on reproductive biology should be used to increase fruit production in both species. Prevailing social conditions in relation to tree tenure, marketing and processing are the major constraints to successful domestication and proper management of these valuable trees. Changes in tree tenure policy, development of local and national markets, access to market information for producers, establishment of a system for standardizing product quality at national level, and development of improved village processing technologies are needed.