Evaluation of mother corm weights and foliar fertilizer levels on saffron (Crocus sativus L.) growth and yield components

•Examination of 3 mother corm weight classes and 5 concentrations of foliar fertilizer.•Mother corm and foliar fertilizer levels affected growth and yield significantly.•The interaction of mother corm and foliar fertilizer levels was significant.•Most favorable combination was mother corms 5–10 g and 15% fertilizer concentration.

This study evaluated the influence of three corm weight grades, <5 g, 5–10 g and >10 g, and five levels (0, 5, 10, 15 and 20%) of Dalfard 15® foliar spraying (specific fertilizer for saffron farms in Iran containing 12% N as NO3−, 8% P, 4% K, 2000 mg L−1 iron chelate, 1000 mg L−1 Zn, 1000 mg L−1 Mg and 500 mg L−1 Cu) on growth and yield criteria of saffron (Crocus sativus L.). For this purpose, an experiment as a factorial layout based on randomized complete block design with four replications was conducted in Research Greenhouse Area of College of Agriculture, Ferdowsi University of Mashhad, Iran during 2008–2010. The result showed that the mother corm weight grades, different levels of foliar fertilizer and their interactions had significant effects on saffron yield components. The highest amount of fresh weight of flower (35.44 g m−2) and dry weight of stigma (0.36 g m−2) were obtained by mother corms 5–10 g and 15% concentration of foliar fertilizer. Daughter corm number increased significantly (241%) by using 15% concentration of foliar fertilizer and mother corm 5–10 g compared with using mother corm <5 g with no fertilizer spraying. The fresh weight of flowers from mother corms <5 g under 20% concentration of foliar fertilizer was statistically the same as the fresh weight of flowers from mother corms 5–10 g and >10 g with 10% concentration of foliar fertilizer. Totaling, 15% concentration of foliar fertilizer and 5–10 g mother corms were the most favorable condition for the entire vegetative and reproductive traits of saffron in this study.