不同株高玉米品种部分群体质量指标对种植密度的反应

Responses of Some Population Quality Indices of Corn Hybrids Differing in Plant Height to Planting Density

试验采用双因素裂区设计,主处理选先玉335、郑单958和高优1号3个不同株高品种,副处理设45000,53250,61500,69750和78000株/hm25个密度,从产量及其结构、叶面积动态、干物质积累与分配、库源关系和群体整齐度等方面研究阐述了不同株高紧凑型玉米品种群体质量指标在密度影响下的变化特点。结果显示,穗粒数、株高整齐度、单株干重、结实率、籽粒库充实度、粒叶比和产叶比等指标因密度处理的变异系数均呈现高秆品种大于中秆、中秆大于矮秆的规律性变化;生育后期叶面积衰减速率,源与库的相对地位、其平衡关系因密度处理的变化趋势也以品种株高不同而不同。高秆品种适宜密度和经济系数低,群体质量易受增密的负作用影响;矮秆品种对密度反应相对迟钝,但单株生产力有限;中等株高品种合理密植,花后干物质积累量大、理论产量高,对密度反应适中,是夏玉米理想的品种类型。

An experiment was carried out by a split block design with two factors of compact corn hybrids of XY335 （high-plant）, ZD958 （medium-plant）and GY1 （short-plant）as main plot and planting densities of 45 000,53 250, 61 500,69 750 and 78 000 plant/hm^2 as sub-plot to describe the variation of population quality indices, such as yield and yield components, leaf area changes, dry matter accumulation and partitioning, sink-source relation, and population uniformity, as affected by hybrid and planting density. It was shown that grain number per ear, uniformity of plant height, dry matter per plant, ratio of seed-set, full degree of sink, grain-leaf ratio and yield-leaf ratio arisen from variable coefficient of planting density treatments regularly declined with hybrid plant height reduction. During late growing stage, change trends of reduction rate of leaf area, relative status and balance relation of source and sink induced by planting density treatments were also varied with the variation of hybrid plant height. High-plant hybrid was shown low for suitable planting density and harvest index, and its population quality was susceptible to planting density increase, however, short-plant hybrid was relatively un-suseeptible to planting density with limited individual productivity. Medium-plant hybrid was ideal hybrid type for more post-silking dry matter accumulation when reasonable planting density sown, high in theoretical yield and adaptation to optimal planting density.