Comparative absorption and utilization of fertilizer nitrogen applied to 'Robusta' banana (Musa x paradisiaca) at different growth stages

An experiment was conducted during 1991-93 to study comparative efficiency of nitrogen absorption and utilzation in 'Robusta' banana (Musa x paradisiaca L.) using 15 N-enriched ammonium sulphate, Nitrogen was applied in 4 equal splits of 50 g each at early vegetative (45 days after planting), late-vegetative (90 days). bud-differentiation (155 days) and Shooting stages of plant growth. After each application absorption and utilization of fertilizer N was monitored by collection of leaf samples at 20-day intervals till bunch harvest. The absorption of fertilizer N [nitrogen derived from fertilizer (Ndff) applied at early and late vegetative stages was faster but decreased gradually to a low value at the time of bunch harvest. However the application at bud·differentiation and shooting stages maintained higher fertilizer N in leaves till bunch harvest. Uptake and utilization of fertilizer N increased with delayed stage of applicalion and the highest utilizalion (38.87%) was obtained when applied at shooting stage and least when applied at early vegetative stage (11.73%).