晋南盆地夏播玉米种植密度对产量及其相关性状变异系数的影响

为确定‘郑单958’玉米品种在晋南盆地夏播的合理种植密度，充分发挥该品种的增产效能，在山西临汾采用随机区组设计方法研究了种植密度对产量及其相关性状变异系数的影响。结果表明：在降雨正常年份，籽粒产量、千粒重、穗长、穗粗和单稳重在不同种植密度间存在差异，而出粒率、稳行数和收获指数不存在差异；种植密度对相关性状的变异系数影响序列为单稳重〉籽粒产量〉千粒重〉穗长〉穗粗〉穗行数〉出粒率〉收获指数；穗长、穗粗和穗轴重对单穗重（籽粒）的贡献大小为：穗长〉穗粗〉穗轴重。晋南盆地夏播玉米增加种植密度可显著提高籽粒产量，其籽粒产量是随干物质积累的增加而协同提高，对收获指数性状影响较小。该项研究为晋南盆地夏播玉米增加种植密度提供了理论和技术支撑。

Effect of planting Density of Summer Maize on Yield and Related Traits Variation Coefficients in the Southern Basin of Shanxi

In order to determine rational planting density of summer maize and to fully develop yield-increasing effect, a field trial with a summer maize variety ＇Zhengdan 958＇ was conducted in 2020 in Linfen, Shanxi Province, China to investigate the effects of different planting densities （ranging from 60000 to 90000 plants/hm2.） on kernel yield and on variation coefficients of related traits in a randomized block design. Significant differences in kernel yield, 1000-kernel weight, cob length, cob diameter and weight/cob were found among different planting densities in normal summer rainfall year, but insignificant differences in kernel weight percentage, rows/cob and harvest index were recorded. The influence of planting density on the variation coefficients of related traits was ranked as weight/cob〉kernel weight/cob〉1000-kernel weight〉cob length〉cob diameter〉rows/cob〉kernel weight percentage〉harvest index. The importance order of cob length, cob diameter and cob-stalk weight to kernel weight/cob was cob length〉cob diameter〉cob-stalk weight. It is concluded that increasing planting density could significantly enhance kernel yield, which had synergistic effect with dry matter accumulation, but no significant effect on harvest index.