Evaluation of salinity stress tolerance indices derived from Cl/SO4 anionic ratios and nitrogen fertilizer in barley (Hordeum vulgare L. var. Nosrat)

Salinity stress has an important role in reducing crop production. Chlorine and Sulfate toxicity in waters and soils are the main factor in reducing growth and yield of most of plants. Tolerance and sensitive indices related to Cl and SO4 in irrigation water and effect of nitrogen fertilizer on barley yield was evaluated in a factorial experiment based on completely randomized design with three replications, under greenhouse condition. Quantitative indices of stress tolerance such as mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), stress susceptibility index (SSI), reduction yield ratio (Yr) and stress tolerance index (STI) were calculated. Results showed that STI had a positive and high significantly correlation with grain yield and plant biomass. Correlation of grain yield and plant biomass with STI index showed that the negative effect of Cl anion was more than SO4 in barley tolerance to salinity. Also Cl/SO4 anion ratios 1:3 and 1:2 in grain yield and 1:2 and 1:1 in plant biomass imposed highest tolerant in salinity compared to non stress conditions.