Interaction effects of salt stress and salicylic acid levels on physiological trials of saffron (Crocus sativus L.)

In order to investigate the effect of salicylic acid on reduction of the effects of salinity stress in saffron (Crocus sativus L.), an experiment was conducted in Torbat Heydarieh during 2015-2017. The experiments were performed as split plots in a randomized complete block design with three replications. The treatments consisted of salinity stress levels at four levels in the main plots: a1 (1.5 ds.m-1), a2 (3 ds.m-1), a3 (6 ds.m-1), a4 (9 ds.m-1) and the sub plots of salicylic acid in four levels including b1 (zero (control)), b2 (0.4mM), b3 (0.8mM), b4 (1.2mM). Results showed that in the highest salinity level (9 ds.m-1), application of appropriate concentration of salicylic acid increased leaf number and leaf length by 3 and 20% in first year and 20 and 32% in second year , respectively. Also, with the application of salicylic acid, leaf sodium content decreased by 40% and Leaf potassium content increased by 38% in second year. According to the results, salicylic acid caused balances in glucose and proline content, decrease of Na absorption, prevent disorders of K absorption and enhanced RWC leaves. At the highest salinity level salicylic acid application caused a 20% increase in total chlorophyll compared to control in second year. In the case of stigma yield, application of 0.8 mM salicylic acid at 6 and 9 ds/m salinity increased dry stigma yield (1.12 and 2.45 Kg/ha respectively)by 81% and 118%, respectively. Therefore we can suggested that application of 0.8 mM salicylic acid in salinity stress conditions in order to enhance stigma yield and saffron growth and decrease negative effects of salinity.