Improving Growth and Yield of Wheat under Drought Stress via Application of SiO2 Nanoparticles

Silicon (Si) and its derivatives have beneficial effects on a wide variety of plant species, especially under both biotic and abiotic stresses. Yet, their effects on wheat (Triticum aestivum L.) plants under drought stress are not well known. Therefore, in order to evaluate the effects of SiO2 NanoParticles (NPs) under drought stress, wheat seeds were separately sown in pots. Then, the SiO2 NPs were added to them through soil and foliar application at three stages of plant growth. Results indicated that drought stress significantly decreased majority of the studied traits compared to the normal irrigation. Soil application of NPs, under drought stress, significantly increased leaf greenness (SPAD) and Relative Water Content (RWC) by 12.54 and 84.04% respectively, compared to the control (NPs = 0 ppm). Moreover, under drought stress, wheat yield also increased by 25.35 and 17.81%, respectively, by foliar and soil application of NPs. Under the same irrigation regimes, soil application of NPs significantly increased plant height and biomass compared to the foliar application of NPs. Finally, our results highlight that usage of the SiO2 NPs, especially at rates of 30 and 60 ppm, can mitigate adverse effects of drought stress in wheat plants.