种植密度对夏玉米产量及其性状的影响研究

以郑单958为试验材料，采用单因素随机区组设计，在田间种植条件下，研究了夏播玉米种植密度对其产量及相关性状的影响。结果表明：在天津地区，夏玉米的单位面积产量先随种植密度的增大而增高，当密度达到一定程度之后，随着种植密度的增加，产量下降，即随密度的增加呈二次曲线模式变化。种植密度对千粒重和穗粒数的影响较为明显，呈一次线性模式下降；对亩穗数、空秆率、穗位高和穗行数影响也较大，呈一次线性模式升高。种植密度对株高的影响不明显。

Effects of Planting Density on Yield and Traits of Summer Maize

Selecting Zhengdan958 as the test materials, an experiment with a single factor and randomized blocks was designed to study the effects of planting density on yield and related traits of summer maize under the field planting conditions. The results indicate that the yield per unit area of summer maize in Tianjin increased firstly with planting density increase, but then decreased when the planting density reached a certain level. In a word, the yield showed quadratic curve changes with the planting density increase. Planting density influenced obviously on 1 000-kernel weight and grain number per ear and showed decrease by linear model. Planting density also influenced obviously on spike numbers, empty stalk rate, ear height and row number per ear and showed increase by linear model. Planting density had no notable effects on height of plant.