Difference in water consumption and yield among different drought-resistant wheat cultivars

Drought is the main factor that restricts wheat yield in the arid land of the Loess Plateau. Selecting suitable wheat cultivars is important to improve wheat yield in this area. To identify differences among 10 drought-resistant dryland wheat cultivars for cultivation in the dryland of eastern Loess Plateau based on annual precipitation range, a field experiment was conducted in Wenxi County, Yuncheng City, Shanxi Province from 2012 to 2017. A few studies have been conducted taking into account drought resistance and annual precipitation range into consideration. In this study, the 10 selected wheat cultivars were screened for drought resistance. Then, the study period was classified as dry year and median year, based on the annual precipitation, and wheat varieties were classified as strong and weak drought-resistant cultivars. We compared differences in water use efficiency, dry matter accumulation, yield, and yield components among the cultivars for five consecutive years, and analyzed the relationships between yield, dry matter accumulation and water consumption. Furthermore, the effect of water saving on the yield of wheat cultivars was determined. The results showed that the strong drought-resistant cultivars were JM92, YH20410, YH22-33, YH618, YH719, and C6697; whereas the weak drought-resistant cultivars were LH6, LH9, LH11, and LH13. In the dry year, average water consumption of the strong drought-resistant cultivars was higher than that of the weak drought-resistant cultivars. When water consumption was increased by 1 mm, the yield of wheat increased by 29.6 kg·hm^-2, and the main factors affecting the yield of the strong drought-resistant cultivars were spike number and grain number per spike. Moreover, dry matter accumulation in the vegetative organs increased by 50.8 kg·hm^-2. Therefore, the water use efficiency of the strong drought-resistant cultivars, especially JM92 and YH20410, was higher than that of the weak drought-resistant cultivars. In addition, water saving per unit grain production of the strong drought-resistant cultivars was 13.61% higher than that of the weak drought-resistant cultivars. The yield increment of 1 mm soil water consumption was increased by 15.74% higher of the strong drought-resistant cultivars compared with that of the weak drought-resistant cultivars. Water consumption of six cultivars with strong drought resistance was generally higher in the median year, and both yield and water use efficiency of JM92 and YH20410 were relatively higher. Therefore, our results indicate that JM92 and YH20410 perform better in both dry year and median year.