Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 20 7 2018 12 01 Improving Growth and Yield of Wheat under Drought Stress via Application of SiO2 Nanoparticles بهبود رشد و عملکرد گندم تحت تنش خشکی از طریق نانوذرات دی‌اکسید‌سیلسیوم 1479 1492 16237 EN F. Behboudi Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran. Z. Tahmasebi Sarvestani Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran. M. Z. Kassaee Department of Chemistry, Collage of Sciences, Tarbiat Modares University, Tehran, Iran S. A. M. Modares Sanavi Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran. A. Sorooshzadeh Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic Republic of Iran. Journal Article 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 (<em>Triticum aestivum</em> 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 SiO₂NPs 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 SiO₂NPs, especially at rates of 30 and 60 ppm, can mitigate adverse effects of drought stress in wheat plants.<br> https://jast.modares.ac.ir/article_16237_2b348ef45c33b63733388ee1f906b8a2.pdf