Effect of field border width for irrigation on dry matter accumulation and distribution, yield, and water use efficiency of wheat

A field experiment was conducted using high-yielding winter wheat cultivar Jimai22 as a test material to examine the effects of different border widths for irrigation on dry matter accumulation and distribution, yield, and water use efficiency of wheat during the wheat growing seasons in 2010 to 2013. Four treatments were installed, i.e., field border widths at 1.0 (W10), 1.5 (W15), 2.0 (W20), and 2.5 m (W25), respectively. In early and middle grain-filling stages, the net photosynthetic rate of W20 was remarkably higher than that of W10 and W15; however, no difference was observed between W20 and W25 at 0 m to 20 m, 20 m to 40 m, and 40 m to 60 m. The net photosynthetic rate of W20 was remarkably higher than that of other treatments. In the late grain-filling stage, the net photosynthetic rate of W20 was remarkably higher than that of other treatments at 0 m to 20 m, 20 m to 40 m, and 40 m to 60 m. In middle and late grain-filling stages, W20 showed the highest transpiration rate and leaf water use efficiency among the treatments, which greatly increased grain filling. Dry matter accumulation in the maturity stage of W20 was considerably higher than that of other treatments. The dry matter distribution to grain and contribution proportion to grain after anthesis, grain filling rate, and 1000-kernel weight of W20 were markedly higher than those of other treatments. The W20 treatment exhibited the highest average grain yield; no difference in grain yield was found in the three regions of the same treatment regardless of the initial border width. Moreover, W20 yielded the highest water use efficiency and irrigation water use efficiency; thus, W20 exhibited the most efficient field border width for irrigation in our study.