摘要： 以郑单958为材料,研究不同施肥时期对穗位上平均叶夹角、叶向值、叶面积指数等植株冠层形态指标与叶片净光合速率、叶绿素SPAD值等光合性能的影响,是通过氮肥调控,构建高效冠层。结果表明:施氮量为180kg⁄hm²时氮肥一次性基施的处理和施氮量为75kg⁄hm²时氮肥8叶展一次性施入的处理穗位上叶夹角较小,茎粗相对适中,叶向值较大,吐丝期和灌浆中期单株叶面积较大,叶面积指数发展动态合理,符合高产玉米植株形态特征,同时叶片SPAD值较大,并且在灌浆中期中上层叶片净光合速率下降较少。说明施肥过早或过晚均不利于冠层结构的优化从而影响植株的光合性能。

关键词: 夏玉米, 冠层构建, 叶向值, 光合速率

Abstract: In this study,different N application timing and levels were applied for understanding the effects on maize canopy structure and photosynthesis traits. The results showed that:canopy structure indexes (leaf angle above ear layer LOV,and LAI,etc.),photosynthesis capability indexes (Pn) of ear layer could be used as standards for the evaluation of high yielding canopy structure. The nitrogen application affected those indexes. When nitrogen fertilizer application rate was 180 kg /ha,it should be applied before sowing as basal fertilizer,by which leaf angle ahove the ear was smaller LAI in the prophase increased faster while reduced slower after Bilking stage,and LOV and Pn were larger in the Bilking stage. When the nitrogen fertilizer rate was 75 kg/ha}8}eaf stage was suitable for achieving good canopy structure. Under N amount of 75 kg/ha} leaf angle above the ear was smaller while LOV was larger and LAI was ideal,and thus Pn was high,therefore this canopy structure was highly efficient.

Key words: Summer Maize, Canopy structure, Leaf oriented value(Lov), Photosynthesis

中图分类号: 

• S143.1