Thi study aimed to assess the physiological effect of foliar silicon on the yield and its components of Bohouth 22cultivar bread wheat under conditions of moisture depletion. A field experiment was conducted at the Research Station E, College of Agricultural Engineering Sciences, University of Baghdad (Al-Jadriyah), during the 2022-2023 and 2023-2024 winter seasons. The nested design with three replicates was used to study three levels of moisture depletion (40%, 60%, and 80%) and four silicon concentrations (0, 150, 200, and 250 mg L^-1).The results showed significant effects of depletion levels and silicon concentrations, with 40% and 60% depletion achieving the highest values ​​for the yield and its components. mean yields for the two seasons reached 5.627 and 4.792 t ha^-1, and the highest water use efficiency for grain yield for the 60% depletion level compared to the 40% depletion factor reached 2.49 kg m³ of water in grains, and their water consumption reached 350.35 mm Season^-1, which made 12.18% of water availability for the two seasons. The lowest values ​​were recorded at the depletion level of 80%.The silicon concentration of 200 mg L^-1 also improved the yield and its components, as a mean for the two seasons. The grain yield reached 5.338 t h^-1, and the water use efficiency of the grain yield amounted to 2.64 kg grains m^-3 water compared to the control treatment sequentially. The interaction of the two study factors also had a significant effect on Most of the attributes.