Effect of irrigation frequency on yield and leaf water use efficiency of winter wheat

In order to investigate the optimal water-saving and high-efficient irrigation pattern of winter wheat in North China, 3 irrigation treatments, irrigating 120 mm only at jointing stage, irrigating 60 mm each at jointing and heading stages, and irrigating 40 mm each at jointing, heading, and milking stages were conducted to study the effect of irrigation frequency on yield and leaf water use efficiency of winter wheat in Huabei Plain of North China. The results showed that under the condition of irrigating 120 mm during the growing season of winter wheat, the treatment which irrigated 60 mm at jointing and heading stages, respectively, the net photosynthesis rate and transpiration rate of winter wheat flag leaves significantly increased at milky stage and dough stage. With irrigating 60 mm at jointing and heading stages, respectively, the water use efficiency in flag leaves was significantly improved at milky and dough stages. The results indicated that irrigating 60 mm at jointing and heading stages during the winter wheat growing season, grain yield was the highest, which can be attributed to increased spike number. Under the condition of irrigation amount 120 mm at the growing season of winter wheat in North China, it was suggest that winter wheat should be irrigated 60 mm at jointing and heading stages to achieve reasonable water use efficiency and grain yield.