%A YANG Ji-Shun, GAO Hui-Yuan, LIU Peng, LI Geng, DONG Shu-Ting, ZHANG Ji-Wang, WANG Jing-Feng %T Effects of Planting Density and Row Spacing on Canopy Apparent Photosynthesis of High-Yield Summer Corn %0 Journal Article %D 2010 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2010.01226 %P 1226-1233 %V 36 %N 07 %U {https://zwxb.chinacrops.org/CN/abstract/article_4585.shtml} %8 2010-07-12 %X

With different plant population densities (6.75´104, 9.00´104, and 11.25´104 plants ha-1), the effects of the deneity and row spacing on grain yield and canopy apparent photosynthesis were studied in this article. The results were as follows: with the increase of planting density, grain yield, leaf area index (LAI) and capture efficiency of photosynthestically active radiation(PAR) in upper leaf layer, as well as canopy apparent photosynthesis (CAP) and canopy respiration (CR) and dry matter quantity increased accordantly; but, chlorophyll content and capture efficiency of PAR in the middle and lower layers of canopy decreased. Within different row spacing treatments, the wide-narrow row spacing were not superior to the uniform one significantly at 6.75´104 plants ha-1. However, at 9.00´104 and 11.25´104 plants ha-1, grain yield, LAI, chlorophyll content, capture efficiency of PAR in middle leaf layer and average rate of CAP after anthesis in row spacing of “80 cm+40 cm” were remarkably higher than those in other three row spacings (uniform, 70 cm + 50 cm, 90 cm + 30 cm); while CR/TCAP (ratio of canopy respiration to total canopy apparent photosynthesis) in row spacing of ’80 cm+40 cm’ was the lowest, compared to the others. From the above, it was suggested that at higher plant density the row spacing of ’80 cm+40 cm’ could enlarge photosynthetic area, enhance PAR in middle leaf layer, increase CAP, reduce CR and improve grain yield.