Effect of Electrical Conductivity and Sodium Adsorption Ratio of Irrigation Water on some Physiological Indices and Yields of Two Rapeseed (Brassica napus L.) Varieties

To study the effect of electrical conductivity (EC) andsodium adsorption ratio (SAR) on the yield and physiological indices of two varieties of rapeseed, an experiment was carried in pot condition. Treatments were EC with 3 levels (0.35, 6 and 12 dSm-1), SAR with 4 levels (0, 6, 12 and 18 from NaCl and CaCl2) and varieties with two levels (Talayeh and Okapy). Traits measured were RWC, concentration of Na, K and Ca, leaf water potential, biomass and seed yields. The result of the analysis of variance showed that the interaction effect of variety by EC on Na concentration, biomass and seed yield were significant. With increasing EC levels, seed yield decreased, but yield reduction in Okapi variety was less than that of Talayeh variety. Seed weight per plant in Talayeh was 2.99 g. and that of Okapi was 3.13 g. In both of varieties, with increasing of EC, concentration of Na increased, but its concentration in Okapy was more than Talayeh. The interaction effect of EC by SAR showed that with increasing treatment levels, leaf water potential, biomass and seed yield decreased, while carbohydrates increased. With increasing SAR from EC1SAR1 to EC1SAR4, yield decreased by 7%, while it was 13.7% from EC2SAR1 to EC2SAR4 and 25% from EC3SAR1 to EC3SAR4. Although EC and SAR causes negative effects on rapeseed growth indices, but their negative on Talayeh variety was less than that of Okapy. Increasing calcium proportion against salinity reduced the effects salinity in all traits. Since, high saline water has higher calcium ion, it would have poper quality for to use it in agriculture.