Improving barley performance by proper foliar applied salicylic-acid under saline conditions

Abstract

<span>Despite general effect of salicylic-acid (SA) in improving plant growth and<br /><span>productivity in saline conditions, there have not been unanimity about the best<br /><span>concentration. In this 2-yr field study the effect of different SA concentrations<br /><span>(0, 0.5, 1.0, 1.5 and 2.0 mM) was examined on growth, grain yield and yield<br /><span>components of barley under two non-saline (2 dS m<span>-1<span>) and saline (12 dS m<span>-1<span>)<br /><span>conditions. By using response curves and regression analyses the best concentration<br /><span>was also determined. The results showed that salt stress decreased barley plant<br /><span>height (22.7%), fertile tillers (19.0%), ear length (21.6%), grain number per ear<br /><span>(22.5%), thousand grain weight (19.9%), biological yield (29.6%) and grain yield<br /><span>(37.6%). Since salinity treatment when imposed the tillers were at their rapid<br /><span>growth phase; therefore, fertile tiller number per unit area was found to be the most<br /><span>sensitive trait to salt stress. Nonetheless, SA foliar application in different<br /><span>concentrations could ameliorate some of these negative impacts on growth, yield<br /><span>and yield components. Reduction percentage of grain yield due to salinity was<br /><span>the lowest at 1.5 mM in first and 1.0 mM SA concentration in second year<br /><span>corresponding to 27.3% and 33.8%, respectively; while those were highest at no-SA<br /><span>treatments (42.2% and 43.8% in first and second year, respectively). Modulating role<br /><span>of SA for adverse effect of salinity could be attributed to enhanced grain number.<br /><span>Based on the result of regression analysis, it can be concluded that SA foliar<br /><span>application at 2.0 mM under non-saline and at 1.41 mM under saline conditions<br /><span>could be considered as the best concentrations for improving barley performance.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span></span></span></span></span>