Effect of plant age and harvest date in the dry season on yield and quality of Gliricidia sepium in southern Nigeria

In a field experiment in southern Nigeria, early harvest dates resulted in high dry matter yields. The dry matter yields also rose as plant age increased. One, two, three and four year old gliricidia plants gave dry matter yields of 2.26, 3.74, 5.23 and 7.13 t per ha, respectively. The crude protein content and in vitro dry matter digestibility decreased while the structural components increased as the dry season progressed. The mineral concentration was not significantly affected by the harvest date and plant age. The macro-minerals Ca, P, Mg, K and Na concentrations were 20.8, 2.19, 3.32, 24.9 and 1.72 g per kg dry matter. The trace elements Cu, Zn, Fe and Mn concentrations were 4.93, 22.4, 306 and 86.1 mg per 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.