Preliminary evaluation of some forest trees for cocoa cultivation

Abstract

Some forest trees were evaluated for their propagation, growth rate and suitability to provide shade in cocoa farms. The tree species were initially selected on the basis of being widely distributed in cocoa growing areas of Ghana. Germination tests including various dormancy breaking techniques were used to raise seedlings. Ricinodendron heudelotii required pre-heating at 40°C for 12 days to achieve about 70% germination. The use of acid scarification for 24 hours achieved only 32% germination which was not different from the control. Other species like Newbouldia laevis, Spathodea campanulata, Alstonia boonei and Pycnanthus angolensis germinated without any pre-treatment. R. heudelotii showed better growth rates than the other species in the field. N. laevis and Antiaris africana were slow growing from seedling transplants. S. campanulata and R. heudelotii provided good ground cover speedily. However, R. heudelotii showed deciduous growth even in the sapling phase whilst S. campanulata did not shed its leaves but rather renewed the leaves gradually such that shade was better provided throughout the juvenile growth period. S. campanulata would therefore be a suitable shade tree species for establishing young cocoa farms. Further evaluation of the growth pattern, shade provision and mineralization of the litter from the species continues.


JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 1, July (1998) pp. 141-150