Effect of planting bed and nitrogen fertilizer levels on growth and yield of saffron (Crocus sativus)

This research aimed to investigate the effect of planting bed and nitrogen fertilizer levels on growth and yield of saffron. For this work a field experiment was conducted in 2016-17 in research farm of Saffron Institute of University of Torbat Heydarieh. Experimental treatments were performed based on a randomized complete block design as split plot arrangement with three replications. Treatments consisted of two levels of planting bed: soil of without planted saffron in previous years (Control soil) (S1) and soil of planted saffron in previous years (Contaminated soil) (S2) as the main-plots; and four levels of nitrogen fertilizer: no nitrogen (0) (N0), 50 (N50), 100 (N100) and 150 (N150) kg/ha nitrogen fertilizer from urea source as the sub-plots. The research results, which was obtained from the data of the second year, showed that planting bed had significant effect on all measured factors. So that application of contaminated soil led to an decrease in 12.72 percent for leaf length, 27.53 percent for corm weight, 31.88 percent for No. of replacement corms, 40.10 percent for No. of flower, 42.53 percent for flower fresh weigh, 42.88 percent for petal fresh weight, 40.01 percent for petal dry weight, 18.71 percent for stamen fresh weight, 26.40 percent for stamen dry weight, 43.41 percent for stigma fresh weight and 56.04 percent for stigma dry weight in compare with control soil. Effect of different nitrogen fertilizer levels was significant on all measured factors. So that consumption of 150 kg/ha nitrogen fertilizer led to increasing amounts of all measured factors. However for saffron reproductive factors such as flower fresh weigh, petal fresh and dry weight, stamen fresh and dry weight, stigma fresh and dry weight wasn’t seen any significant different between treatment of 150 and 100 kg/ha nitrogen fertilizer.