00633naa a2200193 a 450000100080000000500110000800800410001910000190006024501320007926000090021165300160022065300290023665300170026565300150028270000130029770000150031070000220032577300920034710321672004-08-25       2003    bl uuuu     u00u1 u    #d1 aANKUMAH, R. O.  aThe influence of source and timing of nitrogen fertilizers on yield and nitrogen use efficiency of four sweet potato cultivars.  c2003  aBatata doce  aEficiencia do nitrogenio  aFertilizacao  aNitrogenio1 aKHAN, V.1 aMWAMBA, K.1 aKPOMBLEKOU, A. K.  tAgriculture Ecosystems & Environment, Amsterdamgv. 100, n. 2-3, p. 201-207, dec. 2003.