Tropical Grasslands (1992) Volume 26, 2124
Effect of plant age and harvest date in the dry season on yield and quality of Gliricidia sepium in southern Nigeria
Obafemi Awolowo University, Adeyemi College of Education, Department of Agriculture, Ondo, Nigeria
An experiment was conducted in southern Nigeria to investigate the effects of plant age and harvest date in the dry season on the forage yield and quality of gliricidia. Early harvest dates resulted in high dry matter yields. The dry matter yields also rose as plant age increased. The total dry matter yields obtained from November 3, December 15, January 26 and March 9 harvest dates were 7.98, 7.11, 0.86 and 2.23 t/ha, respectively. One, two, three and four year old gliricidia plants gave dry matter yields of 2.26, 3.74, 5.23 and 7.13 t/ha, respectively. The crude protein content and in vitro dry matter digestibility decreased while the structural components increased as the dry season progressed. The mean crude protein, acid detergent fibre, lignin, cell-wall constituents and cellulose contents, and in vitro dry matter digestibility were 25.9, 28.5, 11.0, 54.4, 14.6 and 62.5% respectively. The mineral concentration was not significantly affected by the harvest date and plant age. The macrominerals Ca, P, Mg, K and Na concentrations were 20.8, 2.19, 3.32, 24.9 and 1.72 g/kg dry matter. The trace elements Cu, Zn, Fe and Mn concentrations were 4.93, 22.4, 306 and 86.1 mg/kg dry matter, respectively. It is suggested that in southern Nigeria, gliricidia may be managed to remain vegetative throughout the dry season by cutting early in the dry season.