Influence of variety and management level on pearl millet production in Niger: II. N and P concentration and accumulation

Pearl millet [Pennisetum glaucum (L.)R. Br.] is generally grown on nutrient-poor soils and low rainfall conditions in Niger. Nitrogen and P accumulation and utilisation are very important factors in pearl millet growth, and are affected by environment and management. An understanding of seasonal N and P accumulation is necessary to improve pearl millet production. A two-year field study was conducted in 1995 and 1996 at Kollo, Niger with the objective to determine N and P concentration and accumulation by pearl millet as affected by variety and management level. Treatments were factorial combinations of three pearl millet varieties: `Heini Kirei', a landrace tall variety; `Zatib', an improved tall variety; and `3/4HK', a short improved variety, with low management (10,000 hills ha-1 with no fertiliser) and high management (20,000 hills ha-1 with manure and N and P fertiliser application). Management level had no influence on N and P concentration even though N and P fertiliser, and manure were applied. Variety influence was small and inconsistent. More N and P were translocated from the stem and leaves to the panicle in the higher rainfall year when grain yield was greater. The shorter variety 3/4HK had less N and P accumulation than the tall varieties likely due to less dry matter production. The average maximum total plant N accumulation for low management was 1.42 g N m-2 in 1995 and 0.62 g N m-2 in 1996, while for high management it was 4.58 g N m-2 in 1995 and 2.45 g N m-2 in 1996. Biomass N use efficiency was not influenced by management in either year, while grain nitrogen use efficiency was 17 g grain g-1 N higher with high management than with low management in 1995. In 1996, grain N use efficiency was 11 g grain g-1 N higher with low management than with high management. The short, early maturing variety `3/4HK `tended to have lower N use efficiencies than the other varieties. Nitrogen and P accumulation, and grain N use efficiency was influenced more by management than variety. Key Words: Nitrogen accumulation, nitrogen use efficiency, Pennisetum glaucum, phosphorus accumulation (African Crop Science Journal: 2000 8(1): 35-48