This study demonstrated that solution culture may not allow differences in salt tolerance between genotypes to be discerned and the diverse genotypic variation found in hydroponics did not correlate with pot and field experiments. The findings suggested that assessing salinity tolerance at the seedling stage may not predict salinity tolerance at the later stages. The exclusion of Na+ and Cl– significantly contributed to salt tolerance and grain yield production in pot and field studies. This work has also established a screening procedure (Experiment 2) that correlated with a field evaluation of grain yield of the barley varieties at a moderately saline site. This study also shows that several processes are involved in salt tolerance and that the correlation of these traits with salt tolerance can differ with the severity of the salt stress. Specific-ion exclusion was correlated with salinity tolerance under mild salinity stress but at high salinity stress osmotic potential rather than ion exclusion was more strongly correlated with salinity tolerance. The present study also suggests that salt exclusion coupled with a synthesis of organic solutes are important components of salt tolerance in the tolerant genotypes and further field tests of these plants under stress conditions will help to verify their potential utility in crop-improvement programmes.