The Effect of Indigenous Growth Media on Allanblackia parviflora A. Chev in Ghana

Allanblackia parviflora A. Chev. also called vegetable tallow tree provides a variety of non-timber forest products of great importance to rural households including shade, timber, medicine and seed oil but attempts have not been made to improve the tree species and increase its production. Consequently, the species is being threatened due to unsustainable exploitation and poor regeneration and cultivation appears as the only viable option. In order to cultivate the species at meaningful scale, it is necessary to establish the optimum range of environmental factors that influence its propagation and growth. This study was therefore designed to investigate Allanblackia growth parameters and bio-accumulation under different growth media in a greenhouse study. The media were: 1) TS = top soil alone, 2) AB soil = Allanblackia soil alone, 3) TS + H = Top soil alone + humus, 4) AB + TS = Allanblackia soil alone + Top soil alone and 5) SAB = Sterilized Allanblackia soil alone. Each treatment was replicated three times in a complete randomized design. The experiment lasted for 18 months. Results showed that Fe was the micronutrient that accumulated greatest in the plant tissue. Among the treatments, Allanblackia soil showed the highest accumulation of Zn in the plant tissue with the top soil showing the least (7.67 mg·kg-l). Humus contributed largely to the bio-accumulation of Cu in the plant tissue. Bio-accumulation of manganese in the plant tissue ranged from 13.30 mg·kg-l to 207 mg·kg-l suggesting difference in manganese absorption by Allanblackia as influenced by the treatments. The growth parameters of Allanblackia parviflory were impacted differently by the growth media. The result was however controversial since no differences were found between growth of seedlings in sterilized Allanblackia soil and Allanblackia soil.

Domestication and Sustainable Use of Genetic Resources of a Native Tree with High Economic Potential in Ghana

Allanblackia parviflora A. Chev., an underutilized fruit tree species commonly found in tropical rainforest of West Africa, has potential for integration into agroforestry systems for economic and environmental benefits. The seed oil of A. parviflora is considered economically important but wild fruits collection produces an average of 40 tons of oil annually. However, over 100,000 tons of Allanblackia seed oil is needed annually by food and cosmetics industries. The need to domesticate and conserve A. parviflora to ensure adequate sustainable supply of seed oil and to sustainably manage the genetic resources is therefore critical. This paper reviews the current state-of-the art on domestication and sustainable use efforts of Allanblackia. Propagation methods have been developed to encourage large scale commercial cultivation, include grafting, rooting of stem cuttings and research into improved seed germination. Range-wide germplasm collection has been undertaken leading to establishment of 140 accessions in a gene bank for future source of germplasm. Mother blocks, i.e. established plots consisting of grafts, seedlings and cuttings, have been established at Rural Resource Centres with 58 elite clones, which have been recommended for distribution to farmers. The diversification of cropping systems to include A. parviflora trees is projected to contribute to community livelihoods development and poverty reduction through large-scale production and supply chain development of the species. Furthermore, the integration of A. parviflora into agroforestry systems is important for the conservation of the genetic resources of the species.