冬小麦–夏玉米周年生产条件下夏玉米的适宜熟期与积温需求特性

本研究旨在探讨冬小麦–夏玉米周年生产条件下黄淮海区夏玉米的适宜熟期与积温需求特性。选用郑单958(ZD958)、先玉335(XY335)、登海605(DH605)、登海618(DH618)和登海661(DH661),设置5月21日、5月31日、6月10日和6月20日4个播期,研究表明,播期对夏玉米生理成熟所需积温无显著影响,各品种生理成熟所需要的积温主要取决于品种自身的特性,DH618、XY335、ZD958、DH605、DH661的生育期和生理成熟所需要积温分别为110、112、116、116、121 d和2800、2880、2945、2950、3025°C d。冬小麦-夏玉米周年生产条件下,夏玉米最大可能的生长期约107~112 d(自6月15日至10月1~5日),积温约2800°C d,难以满足现有品种的生产需要。夏玉米直播晚收、冬小麦适期晚播有利于周年产量提高,但目前广泛推广的夏玉米品种生育期过长(约120 d),适时晚收仍难以完全生理成熟,机收籽粒损伤严重。可见,冬小麦–夏玉米周年生产条件下夏玉米最大可能的生长期和有效积温不能满足目前广泛推广的夏玉米品种所需生育持续期和积温,且适时晚收仍难以完全生理成熟,黄淮海区亟需生育期适宜(生育期≤107 d)的高产夏玉米新品种。

Suitable Maturity Period and Accumulated Temperature of Summer Maize in Wheat–maize Double Cropping System

Five summer maize hybrids Zhengdan 958 (ZD958), Xianyu 335 (XY335), Denghai 605 (DH605), Denghai 618 (DH618), and Denghai 661 (DH661) were used with treatments of four seeding dates on 21 May, 31 May, 10 June, and 20 June to explore the accumulated temperature and growth period of summer maize in wheat–maize double cropping system. There was no significant effect of seeding dates on the required accumulated temperature making physiological maturity, which mainly depended on the nature of varieties. DH618, XY335, ZD958, DH605, and DH661 had the growth period of 110, 112, 116, 116, and 121 d, and required accumulated temperature of 2800, 2880, 2945, 2950, and 3025°C d, respectively. In wheat–maize double cropping system, the largest possible growth period was 107120 d (from 15 June to 15 October), the accumulated temperature was about 2800°C d, which was difficult to meet the needs of production for main maize hybrids. The double late-cropping patterns were conducive to increasing grain yield. However, the growth period (about 120 d) of summer maize hybrids planted most popularly was too long to reach full maturity, resulting in serious grain damage when harvest by machinery. In conclusion, at present, the largest possible growth period and accumulated temperature are not possible to satisfy the needs of the production of main maize hybrids in wheat–maize double cropping system, even timely late harvest is still difficult to complete physiological maturity. Therefore, we need early-maturing (growth period ≤ 107 d) and high-yielding summer maize hybrids in the Yellew-Huaihe-Haihe Rivers Plain.