Survival, growth performance and reproductive biology of Allanblackia parviflora A. Chev., a high valued indigenous fruit tree species in Ghana

Abstract

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.