Different irrigation levels were tested on winter wheat to see how they affect plant growth, water use efficiency, and grain yield. The researchers found that giving more water during the flowering stage led to higher grain yield and water use efficiency. However, providing less water during the jointing stage reduced water consumption later on. The best irrigation regime for winter wheat was found to be a combination of moderate water supply at jointing and ample water supply at flowering. This approach resulted in higher photosynthetic rates, increased dry matter accumulation, and ultimately, higher grain yield.