e-ISSN 2231-8542
ISSN 1511-3701
Chuks I. Ogbonnaya
Pertanika Journal of Tropical Agricultural Science, Volume 15, Issue 3, December 1992
Keywords: Gmelina arborea, latosolic soil, N and P nutrition; physical properties of wood.
Published on:
The effects of various doses of N and P fertilizers and their combinations on the growth and physical properties of Gmelina arborea Roxb seedlings on latosolic soil were investigated. Four levels of N and P (0.0, 9.5, 19.0 and 28.5 g/plant corresponding to 0,1,2 and 3 levels, respectively) were applied in all possible combinations. N was supplied as calcium ammonium nitrate and P as superphosphate. Zero levels ofN and P (NOPO) were incorporated as the control. N and its combinations with P contributed significantly to improved wood specific gravity, plant height growth, radial growth (root collar diameter), and dry matter production. N and NP combinations were also the most effective in above-ground production (i.e. low root-shoot ratio) compared to P alone and the control. Leaf area ratio (LAR), however, was reduced by most of the nutrient combinations compared with the control. N1P3 produced the best wood specific gravity, N1P2 the most height growth, N3P1 the most radial growth and dry matter production, N3P2 the highest LAR, while the lowest root-shoot ratio or highest shoot production was obtained with N2P0 and N3P1 nutrient combinations. Nutrient combinations involving N and P in the ratio of 3:1 (N3P1) are recommended for the growth of G. arborea seedlings on latosolic soil at the nursery or early establishment stage in the field.
ISSN 1511-3701
e-ISSN 2231-8542