Dynamic characteristics of leaf area index and their effects on yield in different density spring-maize

صينى. 研究了两个品种吉单209（JD209）、郑单958（ZD958）不同密度群体各生育期LAI动态变化特征，并分析了主要动态特征参数与产量及产量构成的关系，探讨春玉米高密度高产群体叶面积系数（Leaf area index，LAI）动态变化特征对产量的效应。结果表明：各密度群体LAI动态变化呈单峰曲线趋势，随密度增加峰值增大，相同密度下ZD958群体LAI大于JD209，表现较强的耐密性。两个品种高产的适宜密度范围是6万～9万株／hm. ，群体的最大LAI在5～7；各生育期的群体LAI与密度呈显著线性正相关，其中抽雄吐丝期LAI对密度的增长率最大，分别为0．583和0．679；灌浆期群体LAI对产量的影响最大，表明此时期是产量形成的关键期。大喇叭口期LAI对穗数、穗粒数影响最大。密度是通过调控群体的LAI和穗数来影响产量构成和最终产量。[著者文摘]

إنجليزي. Investigate the characteristics of dynamic development leaf area index（LAI） and analysis the relationship between the parameter exchange of LAI and yield and yield components used the two spring-maize（zea mays L.） varieties, Jidan209（JD209） and Zhendan958（ZD958）, in different density spring -maize populations, in order to understand the effect of the characteristics of dynamic development LAI on yield. The results indicated that the dynamic development leaf area index（LAI） showed the direction of single apex curve, and the peak value increased with the density increasing. The LAI of ZD958 was greater than JD209 in the same density that indicated ZD958 was stronger in the patience of dense. The density of 60 000 - 90 000 plants/ha was the range of optimum density to high yield. LAI of every growth duration density linear correlation, the highest value of increase ratios between LAI and density at reproductive growth stage were 0.538 and 0.679 respective in the two varieties. The most effect of LAI on yield at filling stage, on ears numbers and grain number per spike were at the full-grown stage, and that indicate filling stage was the key stage of yield formation. It was obvious that effect of density on yield and yield components by the way of controlling LAI of population and ears numbers.