In this study, we investigated the effects of epibrassinolide spraying at different growth stages on grain yield and nitrogen use efficiency (NUE), and uptake efficiency (UPE) of wide-belt sowing wheat. The results showed that epibrassinolide spraying enhanced wheat grain yield by increasing the number of kernels per spike and (or) 1000-kernel weight, and improved NUE by promoting aboveground nitrogen accumulation and improving UPE. However, the magnitudes of such enhancements in yield and NUE differed among spraying times. Spraying epibrassinolide at the erecting and filling stages, jointing and filling stages, erecting, jointing, and filling stages, as well as erecting, flowering, and filling stages, produced the greatest increase in the number of kernels per spike and 1000-kernel weight, which led to substantial yield increases (12.8%-14.0%), and the greatest increase in aboveground nitrogen accumulation, which improved UPE by 16.4%-18.8%, and resulted in a significant improvement in NUE. Therefore, spraying epibrassinolide at the erecting and filling stage or jointing and filling stages could achieve high yield and NUE in wide-belt sowing wheat.
为明确协同提高宽幅播种小麦产量和氮素利用率的表油菜素内酯喷施时期,研究了不同生育时期喷施表油菜素内酯对小麦产量和氮素吸收利用的影响。结果表明: 与喷施清水对照相比,喷施表油菜素内酯可通过提高小麦穗粒数或(和)千粒重提高产量,通过促进地上部氮素积累提高氮素吸收效率,进而提高氮素利用率,但不同时期喷施效果存在差异。起身期+灌浆期、拔节期+灌浆期、起身期+拔节期+灌浆期、起身期+开花期+灌浆期喷施处理在所有处理中穗粒数和千粒重增幅最大,产量增幅最高(12.8%～14.0%);同时地上部氮素积累量增幅最大,氮素吸收效率增幅最高(16.4%～18.8%),从而氮素利用率增幅最高。综合施用成本等因素,生产上可采用起身期+灌浆期或拔节期+灌浆期2次间隔喷施模式,实现宽幅播种小麦高产高效栽培。.
Keywords: epibrassinolide; exogenous spraying; nitrogen use efficiency; wheat; yield.