University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 51 9 2020 11 21 Investigating the Effect of Spraying Silica Nanoparticles in Increasing the Drought Resistance of Millet Seedlings in Kashmar Weather Conditions Investigating the Effect of Spraying Silica Nanoparticles in Increasing the Drought Resistance of Millet Seedlings in Kashmar Weather Conditions 2307 2322 77037 10.22059/ijswr.2020.302497.668606 FA Mahdi Mokari Water Engineering Department, Agriculture Faculty, Kashmar Higher Education Institute, Kashmar, Iran Meysam Abedinpour Water Engineering Department, Agriculture Faculty, Kashmar Higher Education Institute, Kashmar, Iran Journal Article 2020 05 12 Today, application of nanoparticles in various sciences including agriculture has expanded greatly. One of the important roles of nanoparticles in agricultural and horticultural production is to increase plant resistance to environmental stresses, such as salinity and water stress. Therefore, the present study investigated the effect of spraying with silica nanoparticles on increasing drought resistance of grain millet. For this purpose, a field research was conducted in the form of split plots in a completely randomized design with three replications. The main plots consisted of four irrigation treatments <em>i.e.</em> 100, 80, 60, and 40 percent of the crop water requirement, and the sub-plots included six spraying treatments with concentrations of 0, 100, 200, 300, 400 and 500 mg/l of silica nanoparticles. The results indicated that the deficit irrigation significantly reduced plant height, grain weight, grain yield, harvest index and water  productivity at 1% level. On the other hand, in all irrigation treatments, spraying with silica nanoparticles could significantly increase grain yield, harvest index and water  productivity. The highest grain yield, harvest index and water  productivity were observed in full irrigation treatment (100% water requirement) and 500 mg/l spraying of nanoparticles and the lowest amount was observed in 40% water treatment without spraying. Due to the severe scarcity of water resources in the arid region of Kashmar, providing 80% of the water requirement of  millet along with spraying with a concentration of 500 mg/l silica nanoparticles is recommended in the tillering stage and flowering to deal with water crisis in the study area. Today, application of nanoparticles in various sciences including agriculture has expanded greatly. One of the important roles of nanoparticles in agricultural and horticultural production is to increase plant resistance to environmental stresses, such as salinity and water stress. Therefore, the present study investigated the effect of spraying with silica nanoparticles on increasing drought resistance of grain millet. For this purpose, a field research was conducted in the form of split plots in a completely randomized design with three replications. The main plots consisted of four irrigation treatments <em>i.e.</em> 100, 80, 60, and 40 percent of the crop water requirement, and the sub-plots included six spraying treatments with concentrations of 0, 100, 200, 300, 400 and 500 mg/l of silica nanoparticles. The results indicated that the deficit irrigation significantly reduced plant height, grain weight, grain yield, harvest index and water  productivity at 1% level. On the other hand, in all irrigation treatments, spraying with silica nanoparticles could significantly increase grain yield, harvest index and water  productivity. The highest grain yield, harvest index and water  productivity were observed in full irrigation treatment (100% water requirement) and 500 mg/l spraying of nanoparticles and the lowest amount was observed in 40% water treatment without spraying. Due to the severe scarcity of water resources in the arid region of Kashmar, providing 80% of the water requirement of  millet along with spraying with a concentration of 500 mg/l silica nanoparticles is recommended in the tillering stage and flowering to deal with water crisis in the study area. https://ijswr.ut.ac.ir/article_77037_067af70cbf140c643f3c77c3c418b5a2.pdf