Enhancing Oat ( <i>Avena sativa</i> L.) Yield Quantity and Quality with Foliar Application of Bulk and Nano TiO ₂ and SiO ₂ in a Semiarid Area

Cereal production, including oats, is often limited in dry areas due to low moisture. To ensure food security and use innovative agronomic techniques to enhance crop resilience, a split‐plot factorial design was used in 2022–2023 and 2023–2024 to evaluate the effects of fertilizers, including bulk and nanoparticle forms of Si (Si‐NPs) (20–30 nm) and Ti (Ti‐NPs) (10–30 nm) at three concentrations: 0, 100, and 200 mg L −1 either separately or in combination in well‐watered (WW) and late‐season water deficit (WD) environments on oat. In WW, the average yields of seed, protein, and biomass were 7357, 828, and 24185 kg ha −1 , and WD significantly reduced them by 18.8%, 18.4%, and 30.1%, respectively. Bulk and NP treatments of Ti and Si fertilizers under WW and WD prevented a significant reduction in these traits. The superiority of Ti‐NPs and Si‐NPs over their bulk counterparts was significant. The combined treatment of Ti‐NPs + Si‐NPs at 200 mg L −1 was the most effective fertilizer treatment, resulting in significant increases in yield of grain, protein, and biomass of 27.4%, 67.8%, and 24.4%, respectively. Ti‐NPs and Si‐NPs significantly enhance oat yield, outperforming bulk forms and offering a sustainable approach to cereal production in arid areas.