不同密度对复播青贮玉米光合特性和产量的影响

摘要

[ Objective ] The purpose of experiment was to provide scientific theoretical basis and technical guidance for the two multiple cropping silage corn varieties. [ Method ] The characteristics of dynamic development, leaf area index (LAI) and dry matter accumulation ( DMA) of two multiple cropping silage corn varieties, XINYU 15 and XINSIYU 10 were investigated, and the relationship between the parameter exchange and yield was analyzed, and yield components used in different density populations was explored in order to understand the effect of the characteristics of dynamic development of LAI on its yield. [Result] 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 XINSIYU 10 was greater than that of XINYU 15 in the same density. LAI of every growth duration density had linear correlation, and the highest value of increasing ratios was between LAI and density at tasseling stage and silking stage. The greatest effect of LAI on yield was shown at those stages, which was proven to be the key stage of yield formation. [ Conclusion] It is obvious that the effect of density on yield and yield components lies in the way of controlling LAI of populationand ears numbers. The optimum density of the two high -yield varieties is between 5 000 and 6,000 plants/ 667 m2.%[目的]为北疆地区复播青贮玉米栽培推广提供科学理论依据和技术指导.[方法]研究两个青贮玉米品种新玉15号(XINYU15)、新饲玉10号(XINSIYU10)在麦后复播条件下,不同密度群体各生育期叶面积指数(LAI)、干物质积累(DMA)动态变化特征,并分析主要动态特征参数与产量及产量构成的关系,探讨复播青贮玉米高密度高产群体叶面积系数动态变化特征对产量的效应.[结果]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,相同密度下新饲玉10号群体LAI大于新玉15号.群体的最大LAI在抽雄吐丝期、灌浆期.此阶段群体LAI对产量的影响最大,表明此时期是产量形成的关键期.[结论]密度是通过调控群体的LAI、穗数和穗重来影响产量构成和最终干物质产量,两个品种高产的适宜密度范围是5 000 ～6000株/667 m2.