Improvement of Some Physiological Traits, Yield and Yield ‎Components of Wheat and Barley by Using Sodium Selenate and ‎Sodium Selenite in Dry Land Conditions

Drought stress is one of the major factors limiting crop yield in dry-lands. To investigate the effect of sources and different rates of selenium on physiological traits, yield and yield components of wheat and barley in dry lands a factorial experiment based on complete randomized block design with three replicates was carried out at the Research Station of Islamic Azad University, Arak Branch, in 2014-2015. Experimental factors were selenium sources with two levels, (sodium selenate and sodium selenite), selenium rates with three levels, (0, 18 and 36 g.ha-1) and two crop plant (wheat and barley). The result showed that, foliar application of wheat with 18 g.ha-1 sodium selenite increased the grains per spike by 9.4% as compared to control and foliar application of barley with 18 and 36 g.ha-1 of sodium selenite increased the grains per spike by 8 and 12%, as compared to control, respectively. Two times foliar applications of these two plants with sodium selenate and sodium selenite increased their relative water content. Foliar application by 18 g/ha of selenium increased the grain yield from 1776.31 kg.ha-1 in control to 1889.92 kg.ha-1, while grain yield was decreased (about 1539.62 kg.ha-1) as compared to control when 36 g.ha-1 of selenium was used. It could be concluded that foliar application of 18 g.ha-1 selenium as sodium selenite or sodium selenite in wheat and barley during stem elongation and emergence of spike increases grain yield in dry land condition.