Published online by Cambridge University Press: 03 October 2008
The effects of soil fertilization and plant age on the nutrient composition of various parts of five Nigerian cassava varieties were studied to identify suitable index plant tissue(s), sensitive growth stage(s) and optimum nutrient concentrations, to develop better fertilizer practices for the crop. The third month from planting was the most sensitive stage for diagnostic sampling, when N status was best reflected in leaf blades and K in petioles. N and P were most concentrated in leaf blades and least in root tubers. The largest root tuber yields after 12 months were associated with leaf blade analyses of 5% N, 0.4% P and 2% K at 3 months after planting.