Investigate Different Levels of Iron Chelate Fertilizer and Foliar Spraying Time on the Economic Yield of Saffron (Crocus Sativus L.)

Saffron is a sterile triploid plant, and iron chelate plays an important role in its growth and development. The experiment was conducted in Kermanshah, Iran, from 2015 to 2018 to evaluate the influence of iron chelate fertilizer on saffron. The experi­ment was laid out in a split-split plot (dummy plot technique) arrangement in a randomized complete block with three replica­tions. Treatments included foliar application of fertilizer in the early, mid, and late vegetative growth stages of saffron growth as the main plot, seven concentrations of iron chelate solution (0, 500, 1000, 1500, 2000, 2500, and 3000 mg L-1) as sub-plots, and three harvest times as sub-sub-plots. The fresh and dry weights of corms, stigmas, and petals, number of daughter corms and flowers, length of stigma, and corm diameter were investigated. Iron chelate content up to 2500 mg L-1 caused an increase in the number of flowers, length of stigma, and fresh and dry weights of petals and stigmas compared to the control. However, the application of 3000 mg L-1 fertilizer reduced the number of flowers, length of stigma, and fresh and dry weight of petals and stigmas compared to the control. Overall, the results showed that a supply of 2000 mg L-1 fertilizer in mid-vegetative growth and the third year of harvest resulted in the highest performance.