SOME FACTORS AFFECTING THE SEEDLING GROWTH AND SURVIVAL OF <em>TRECULIA</em> <em>AFRICANA</em>

Abstract

The effects of six environmental factors on the growth and survival of Treculia africana were investigated using multiharvest experiments set out in random design. Full sunlight caused heteroblastic leaf development and produced significantly better
growth in dry weight than in 70% shade as from the first harvest. Growth was significantly better in wet soil condition than in the other soil moisture conditions but at different harvest, the least growth being in the water-logged condition. Humus soil produced significantly better growth than the other soil types with the least growth being in sand. The addition of fruit pulp to either sand or red earth significantly improved growth. Acid medium (pH 5.5) significantly enhanced growth better than basic medium (pH 7.5) as from the second harvest. Increase in leaf weight was mainly responsible for the difference. Salinity decreased growth to the extent that seedlings at 30 to 50% sea water concentrations died before the first harvest while those at 20% sea water died at the last harvest. The possible roles of these factors in restricting the distribution of the species to the moist tropical rain forest are discussed as well as the use to which the results could be put in cultivating the species.