Relationship between nitrogen and phosphorus use efficiency in saffron (Crocus sativus L.) as affected by mother corm size and fertilization

Abstract

Field experiments were conducted to determine the effects of mother corms size and type of fertilizer on acquisition and use efficiency of nitrogen (N) and phosphorus (P) in Saffron, at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. The experiment designed as factorial-split with three replicates, 12 main plots [mother corm size (4g and lower, 4.1–8g, 8.1–12 gand over 12g)×fertilization (composted cattle manure 25tha−1, chemical fertilizer (N 300kgha−1 + P 100kgha−1 and control)] and two sub-plots (first and second year). In both years, the larger mother corms (8.1–12g and more) resulted in a greater nitrogen content (gm−2) in daughter corms and the whole plant. In addition, acquisition and use efficiency of (N) and (P) were increased with increasing mother corms size. In both years, (N) and (P) use efficiency in composted cattle manure treatment was significantly higher than that of chemical fertilizer (by 21 and 61%, respectively). There was a positive and significant correlation between (N) use efficiency and (P) use efficiency (R2=0.98**) and between (N) harvest index and (P) harvest index (R2=0.99**).