种植方式对华北春玉米冠层结构与光合特性的影响

Canopy Structure and Photosynthesis Traits of Spring Maize in Response to Planting Geometries in North China Plain

研究双株错位、双株对位、单株错位、单株对位种植方式对金海5号冠层结构及光合特性影响。结果表明,错位种植显著减小玉米穗下茎叶夹角1.9°~2.5°,增加穗位高和茎粗;吐丝前各种植处理冠层LAI均低于常规单株对位,中后期双株处理(双株对位和双株错位)下冠层LAI衰减缓慢,表现出高效冠层潜势;双株对位的冠层结构失衡,穗位叶净光合速率(Pn)下降,光能利用率最低;双株错位冠层内光分布合理,中后期穗位层透光率提升41.64%,棒3叶Pn增强并能持续较长时间;相比常规单株对位种植,其他3种处理在穗部性状、产量构成因素表现较优,双株错位处理的穗粒数和千粒重比常规单株对位种植显著增加,秃尖短,产量最高,具有改善冠层结构和功能的增产潜势。

The effects of four planting geometries on canopy structure and photosynthesis traits of Jinhai5 were studied. The results indicated that the potential advantage of high-yielding structure and function were well re- vealed when planting maize in two plants per clump and clumps staggered in adjacent rows. The stem-leaf angle un- der the lamina of the ear decreased by 1.9^-2.5~ in staggered form treatments（SC and DC）, respectively, compared with conventional opposite forms, while different tendency revealed in stem diameter and ear height. Leaf area index （LAI） for clumped and staggered forms during the vegetative growth stages was lower than that in DD planting treat- ment, and exceeded it after the silking stage, keeping higher values in grain filling and inferior efficiency of photo- synthesis. However, the relative favorable microclimate and proper light distribution ,especially that the percent transmission of SC in the lamina of the ear in later stages increased by 41.64% than that in others, contributed to the higher photosynthesis（Pn） and delaying senescence due to a more uniform plants distribution of SC. Grain yield was not significantly bigger for clumped and staggered planting geometries, yet increased number of kernels per ear, seed mass and optimizing the ear characters in SC, suggesting the ability of the high-yielding.