EFFECTS OF DIFFERENT LEVELS OF SODIUM CHLORIDE ON YIELD AND CHEMICAL COMPOSITION IN TWO BARLEY CULTIVARS

Salinity of agricultural lands and irrigation water is the most limiting factor for plant growth in many dry parts of the world. Twenty five million ha of agricultural lands are saline in Iran, and this is increasing due to poor irrigation management. Particularly in irrigated agricultural areas, has been found to reduce barley yields, dramatically. To investigate the effects of sodium chloride on two barley cultivars, four levels of salinity: 0, 4, 8 and 12 dS/m, were employed as a factorial experiment arranged in a randomized complete block design with four replications in a controlled environment of the greenhouse during 2007-2008. The results indicated that increasing salinity from 0 to 12 dS/m, decreased the emergence percentage, significantly. The two cultivars (Afzal & Reyhan) responded differently to salinity, so that Afzal showed a significantly higher emergence rate. This cultivar (Afzal) also had greater shoot potassium content. The number of tillers and leaves per plant and also the plant height were decreased upon increasing salinity level. The shoot sodium content was also increased by increasing the salinity level in both cultivars, however, the sodium content of Afzal cultivar, compared to Reyhan cultivar, was lower, probably due to Na+ exclusion mechanisms in this cultivar. The results also revealed that the highest grain number and phytomass was obtained from Afzal cultivar at the lowest salinity level. Phytomass and grain yield were also decreased upon salinity, significantly. Overall, it appeared that less adverse effect of salinity on Afzal cultivar may indicate that this cultivar it might be suitable for saline soils, an object which worth more investigations