Effects of Deficit-Regulated Irrigationon Yield and Water use Efficiency ofWinter Wheat in Xinjiang, China

The present study was conducted at the Xinjiang Qitai Wheat Experiment Station from 2023 to 2024 with the objective of assessing the effects of different irrigation levels on the yield and water use efficiency of drip-irrigated winter wheat under deficit-regulated irrigation conditions.A two-factor splitzone group design was employed to evaluate the responses of New Winter 22 (A1) and New Winter 18 (A2) varieties under six distinct irrigation levels.The results demonstrated a distinctive trend in the leaf area index (LAI), relative chlorophyll content (SPAD), and soil water content within the 0-80 cm layer, exhibiting an initial increase followed by a decline throughout the crop's lifespan.As the irrigation frequency was reduced, the total volume of water consumed and the yield-related indices declined.Conversely, water use efficiency demonstrated an "N"-shaped growth trajectory, reaching its maximum value at a specific point.Notably, the highest yield of 7100.04 kg ha-1 was observed in the W5 treatment group.Accordingly, the A2 variety, irrigated by drip at a rate of 3360-4440 m ha-1, proved to be the optimal combination of varietal water volume under the conditions of this experiment.