Optimizing Winter Wheat Yield and Water Conservation: A Focus on Deficit Irrigation During Reproductive Stages

Studies have identified optimal irrigation amounts and sowing densities for high yield and water conservation in winter wheat. For instance, research indicates that an irrigation amount of 300 mm is optimal for maximizing yield (Sun et al., 2006). Additionally, a sowing density of 525 to 600 plants m-2 with 75 mm irrigation at pre-sowing and jointing stages has been shown to be effective for water conservation and high yield (Gao et al., 2021). However, insufficient irrigation, particularly during critical reproductive stages, can significantly reduce yields. Studies have shown a yield decrease of 16.9~19.5% when irrigated with only bottom moisture water compared to two irrigation events, primarily due to water stress during the reproductive period (Wang et al., 2018). The green-jointing and heading stages before wintering and the filling stage are particularly sensitive to drought. Drought after flowering negatively impacts photosynthetic characteristics of flag leaves, shortens the duration of photosynthesis, and promotes senescence of flag leaves (Yang et al., 2000; Wu et al., 2014). Therefore, investigating the water stress of deficit irrigation at each reproductive stage is crucial for developing water-saving wheat practices and ensuring long-term sustainability.