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Allanblackia is a dioecious multipurpose tree genus of the family Clusiaceae occurring in the equatorial rainforests of Africa extending from Tanzania to Sierra Leone. Besides its traditional main use for producing edible oil from its seeds, local communities use Allanblackia species as medicine and timber. A few years ago, the food processing industry discovered Allanblackia oil with its specific exceptional characteristics as a new ingredient in the sustainable manufacture of products such as margarine. Currently the potential market demand for Allanblackia oil (estimated as over 100,000 tons/year) cannot be met by harvesting fruits of wild Allanblackia species (A. floribunda in Nigeria, A. parviflora in Ghana and A. stuhlmannii in Tanzania), which yields only 200 tons/year. To address this and the challenges of over-exploitation and decreasing Allanblackia abundance in the forests, ICRAF and its partners from the public and private sector are domesticating the species since 2002 using participatory tree domestication approach. The program includes community sensitization, exploration, participatory selections of superior mother trees, conservation in field genebanks, development of agroforestry systems with Allanblackia and market development. Secondly, the program consists of developing asexual and sexual propagation protocols, which are necessary to overcome challenges in multiplication such as seed dormancy, long juvenile phase and high variability of desired traits. Experiments are mainly performed in 'Rural Resource Centres' (RRCs), which serve as diffusion hubs for new technologies, germplasm and knowledge. RRCs have their own tree nurseries, motherblocks and demonstration plots, and train farmers in Allanblackia propagation and cultivation techniques. In addition, RRCs support private satellite nurseries in the villages nearby to reach remote farmers. The domestication programme of Allanblackia through public-private partnership and participatory tree domestication could serve as a model for domestication of other underutilized African tree species of high economic potential.

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The genus Allanblackia consists of multipurpose, valuable non-timber forest tree species found in the rain forest zones of Africa. The seed oil of Allanblackia spp. has a high commercial value and demand for industrial purpose amounting to [100,000 kg oil per year. Wild harvesting from Ghana, Nigeria and Tanzania cannot meet the market demand for Allanblackia oil, hence the need for domestication. A genebank of A. parviflora A. Chev. was established in Ghana in July 2007 for conservation of the genetic resources of the species and for future use in its domestication programme, using 406 seedlings derived from collections made from eight different populations in three different provenances in Ghana. Six years after establishment, the survival rate, growth parameters (height and diameter), reproductive biology (flowering and fruiting behaviour, flower colours and sex ratio of the trees) were assessed. The mean survival rate was 73.65 %. There was no significant difference in mean tree height (cm) (F = 1.017, df = 7, P [ 0.05) and mean diameter at breast height (F = 1.683, df = 7, P [ 0.05) among the populations. Mean tree height (F = 0.309, df = 2, P [ 0.05) and mean diameter at breast height (F = 0.686, df = 2, P [ 0.05) were also not significantly different among the provenances. There was a highly significant positive correlation between the volume of the tree and the number of fruits per tree (R = 0.483, P \ 0.0001), suggesting that fast growth could be an index for productivity and should be considered during selection.