The use of silicon is an option for reducing the adverse effects of water deficit conditions. The recent study took place at the Agricultural Research and Experiment Station of the Faculty of Agriculture, Cairo University, Giza, Egypt (30°02′ N and 31°13′ E, with an altitude of 30 m) in two seasons of 2019 and 2020. The study’s chief objective aimed to investigate the effect of water deficit at flowering on maize and its relation to silicon spraying. The study included two water treatments: non-stress (NS) and water stress (WS); three silicon treatments: (0, 3, and 6 mM L^-1); and five single-cross hybrids. A split-split plot under the concentration of 6 mM L^-1. The most interesting observation in the study showed the noteworthy increase in oil yield/ha for all studied hybrids, ranging from 13.33% (SC-3444) to 29.41% (SC-3433). It resulted from the application of the concentration of 6 mM L^-1. The hybrids SC-30N11, SC-3433, and SC-3444 proved the best hybrids, displaying tolerance to water.

Keywords: Maize (Zea mays L.), water stress, silicon, yield, carbohydrate, protein, oil, stress-tolerance index

Key findings: The water deficit condition at the flowering stage caused a significant reduction in yield and its components in maize. The silicon treatment 6 mM L^-1 concentration notably enhanced the grain and oil yields and carbohydrates.