Effects of Calcium and Potassium Silicate Fertilizers on Agronomic and Biochemical Traits of Two Rice Cultivars Under Drought Stress Conditions

Silicate (Si) has potential effects on crops under different stresses. It can affect biochemical and physiological parameters and reduce drought stress destructive effects. This study aimed to investigate the effects of Si on morphological and biochemical traits under drought stress in two rice cultivars of Local Tarom and Shiroodi. The experiment was organized in completely randomized blocks in a factorial design. Silica treatments included potassium silicate, calcium silicate and a combination of the two at the rates of 0 and 350 kg/ha. Drought stress at the time of cluster emergence and stress during redistribution and water scarcity (soil matric potential of -0.05 MPa) with three replications. Under the conditions of water shortage, stem and seed silica, stem cellulose, and lignin were increased. After silicon treatment, some morphological characteristics such as plant height, harvest index, and grain yield. After the application of silica, leaf blast disease decreased (34%) compared to control. Water stress conditions showed adverse effects on fertile tillers, number of tillers per plant, number of panicles and number of seeds per panicle. The two rice cultivars significantly differed in plant height, panicle length, number of effective tillers, number of panicles per plant, flag leaf chlorophyll, harvest index, the Uptake of copper, manganese, nitrogen, and biochemical traits. The combined effect of water stress on the two cultivars studied did not significantly differ, and therefore, both could be suggested for cultivation under water stress conditions. The results showed the potential effect of silica in alleviating water stress impact, and thus silica treatment may be recommended to increase drought stress tolerance in rice plants.