Efficacy of Salicylic Acid as a Cofactor for Ameliorating Effects of Water Stress and Enhancing Wheat Yield and Water Use Efficiency in Saline Soil

Abstract

Water stress and soil salinity have detrimental effects on crop productivity, water use efficiency as well as soil properties. In attempt to elucidate whether salicylic acid (SA) could ameliorate the detrimental effects of water stress on wheat under salt affected soil, two seasons (2015/2016 and 2016/2017) of field experiments were investigated using six combinations of two salicylic acid levels (zero and 200 ppm SA) and three irrigation treatments (50, 70 and 90% depletion of the available soil moisture). Results showed that exogenously applied SA inhibited Na uptake and stimulated N, P and K uptake under stress conditions. Under water stress, the foliar application of SA effectively increased the relative water content and proline content whilst decreased stomatal conductance compared to the untreated ones. These changes resulted in increment the yield-related traits viz., number of grains spike−1, 1000-grain weight and number of spikes m−2. Water use efficiency attained the maximal values under 50% DAM plus 200 ppm SA, which was on par with 70% DAM plus 200 ppm SA. It was concluded that the potency of SA–treated wheat crop can relatively convert used water into grain yield under water stress conditions as well–watered..