Leaf nitrogen and chlorophyll as indicators for salt stress

The effect of salinity on nitrogen absorption and leaf chlorophyll content of wheat (cv. Falat) was studied in two separate greenhouse traits, both in a completely randomized block design with three replication. Three levels of nitrogen (0, 1.19 and 5.94 g Urea/pot) and three levels of salinity (0, 150 and 300 mol/m3 salts) were used as treatments. Salinity conducted by combining sodium and calcium chloride in a 1:10 molar ratio and pots were irrigated with modified Hogland solution in close system. Leaf chlorophyll and nitrogen contents, stomatal resistance, specific leaf weight (SLW) specific leaf nitrogen (SLN) were measured at booting and anthesis stages. The results showed a high correlation between SPAD reading (leaf chlorophyll) and leaf nitrogen content and SLN. Leaf nitrogen content reduced but SLN and stomatal resistance increased by increasing salinity levels. SPAD reading increased up to salinity levels of 150 mol/m3 but reduced at higher salt concentration. Adjusted SPAD reading on SLW (SPAD/SLW) showed higher correlation with salinity levels compared to unadjusted SPAD reading and may used as indicator for severity of salt stress.