It is of great significance that exploring the characteristics of wheat-maize varieties combination suitable for stress resistance, high yield, and stable yield under the “double delay” system and their matching properties with natural resources, for ensuring the high yield and high efficiency production of winter wheat and summer maize in this region. In this study, field experiments were conducted from 2017 to 2019. Eight winter wheat and eight summer maize varieties were the main varieties in the North China Plain under winter wheat-summer maize “double delay” system with different irrigation treatments. Based on the analysis and evaluation of water use efficiency, grain filling characteristics, growth process, annual light, temperature, and water use efficiency, etc., the characteristics of wheat-maize varieties combination and resource use efficiency under the “double delay” system of winter wheat and summer maize were explored. The results suggested that among the tested wheat varieties, the yields of Jimai 325, Shimai 15, Nongda 3486, and Jimai 22 under conventional water-saving irrigation and rain-fed mode were higher than the average yield of the tested varieties druing the two growing seasons. In addition, the drought resistance index of Jimai 325 and Shimai 15 were higher than that of Jimai 22. Meanwhile, the grain-filling rate, grain number per spike, grain weight, and high stability coefficients of Jimai 22, Jimai 325, and Shimai 15 were higher than the mean of the tested varieties under different irrigation modes. Among the tested maize variaties, the yield and high stability coefficients of Denghai 605, Weike 702, MC670, and Nonghua 816 were all higher than the means of the tested varieties. The grain-filling rate of MC670, Denghai 605, and Xianyu 335 were higher than the means of the tested varieties during the two growing seasons. While, Dika 517 and Xianyu 335 had the lowest grain water content at harvest stage but the highest average dehydration rate among the tested varieties. Based on the comprehensive analysis of the yield and yield stability, drought resistance, grain-filling properties, and dehydration characteristics, the variety combination of Jimai 325-MC670 was selected with the highest annual yield and resource use efficiency. Compared with the local control combination of Jimai 22-Zhengdan 958, the annual yield increased by 17.2% and 17.9%, the light, temperature and irrigation water use efficiency increased by 18.6% and 20.0%, 18.1% and 18.9%, 17.4% and 18.1%, and increased economic benefit 8800 Yuan hm -2 and 9600 Yuan hm -2, respectively; to fit the whole-process mechanized management mode of wheat-maize double cropping system, maize could use varieties with fast dehydration rate and low grain water content when harvest, such as Dika 517 or Xianyu 335. Compared with the current local combination of Jimai 22-Zhengdan 958, this combination could increase the annual yield by 4.7% and 14.4%, and increase the light, temperature, and irrigation water use efficiency by 5.6% and 16.3%, 4.7% and 15.4%, 5.0% and 14.6%, and increased economic benefit by 2080 Yuan hm -2 and 7080 Yuan hm -2, respectively. In summary, optimizing the wheat-maize variety combination under the “double delay” cropping system can further improve the annual yield and resource use efficiency synergistically compared with the local staple wheat-maize variety combination.
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