Nutrients, Osmotic and Oxidative Stress Management in Bread Wheat (Triticum aestivum L.) by Exogenously Applied Silicon Fertilization Under Water Deficit Natural Saline Conditions

Purpose: Salinity and drought are the main abiotic stresses which affect agricultural crop production worldwide. Various approaches and beneficial amendments are used to increase crop stress tolerance and production under world prevailing water deficit and saline conditions. Methods: Our experiment was planned to assess the beneficial role of silicon under water deficient and natural saline condition for increasing wheat crop growth, yield and production. Four levels of silicic acid i.e. 50 kg ha, 100 kg ha, 150 kg ha and 200 kg ha were applied with three irrigation levels i.e. one irrigation, two irrigation and four irrigation in moderately saline soil of EC 7.34 under field conditions using RCBD split plot experimental design. Results: Different growth (i.e. plant height, no. of tillers, spike length, thousand grain weight, biological yield and grain yield), physiological (i.e. chlorophyll contents, relative water contents, membrane stability index and osmolality), antioxidant activity (i.e. SOD, POD and CAT) and elemental analysis (i.e. nitrogen, phosphorus, potassium, zinc, sodium and silicon concentration) were checked in our study. Salinity stress and lower irrigation levels significantly reduced all tested parameters except of osmolality and Na + concentration while antioxidant enzymatic activity remained similar in different levels of irrigation with no silica application i.e. Control. Si fertilization in higher doses i.e. 200 kg ha increased growth parameters maximum by 61%, physiological parameters by 45%, antioxidant activity by 36% and nutrients concentration by 46% decreasing the osmolality by 26% and Na concentration by 48% in wheat. Conclusions: It was concluded that inclusion of Si fertilization in plant nutrition increases wheat crop growth and production by improving plant stress tolerance attributes, nutrients balance and minimizing negative effect of osmotic and oxidative stress under naturally prevailing water deficit saline conditions.