The Enugu pitwood plantations, Nigeria.

The development of coalmining in Enugu in about 1912 led to the formation of a plantation to supplement the supplies of mangrove pitprops brought by rail from Port Harcourt. The props were required in lengths of 4 to 12 foot, with a minimum top diameter of 1 inch per foot. Despite a rainfall of 72 inches per annum, silviculture was not easy on the heavily-farmed and degraded lateritic soil of the area. Of many species tried, Tectona grandis and Gmelina arborea have proved the most satisfactory. Both are now grown on a coppice and clear-felling system with a fifteen-year rotation ; this produces at least one 12foot pitprop per tree. Both are equally acceptable as mining timbers and have similar silvicultural demands. Gmelina is less exacting than teak, but has a pronounced tendency to taper. New plantations are established by taungya farming (tree planting with an agricultural crop).