Effect of concentrations of different growth regulators on corm dormancy and flower yield of saffron in hydroponic conditions

Saffron (Crocus sativus L.) is a perennial stemless herb of the Iridaceae family. It is a triploid plant and sterile geophyte propagated by replacement corms. It has long been known that the relative levels of plant hormones and growth regulators control dormancy, germination and emergence. In order to evaluate the effect of different chemical regulators and their concentrations on corm prolong dormancy, flower and stigma yield of saffron in hydroponic conditions, an experiment was conducted as factorial layout based on a randomized complete block design with three replications at the Agricultural Research Filed of Fadak in 2014. Three chemical regulators at four concentrations such as Gibberellic acid (GA3), (0, 5, 20 and 40 mg.l-1), Chlorocholine chloride (CCC) (0, 100, 200 and 300 mg.l-1) and Naphthaleneacetic acid (NAA) (0, 100, 200 and 300 mg.l-1) were considered as treatments. Studied traits were fresh weight of flower, stigma length, fresh weight of stigma, dry weight of stigma and flower number in October and December. The results showed that the effect of concentration was significant (p≤0.01) in flower yield indices at the first harvest. Flower yield indices were significantly affected for growth regulators and concentrations at the second harvest (p≤0.05). By increasing concentration of growth regulators declined fresh weight of flower, flower number, stigma length, fresh weight of stigma and dry weight of stigma. The highest stigma length and flower number were observed for CCC with 0.34 cm and 3.41, respectively. It is revealed that plant hormones have considerable role in dormancy prolongation and flower yield indices of saffron.