播期对夏玉米叶片生长发育特性的影响

Effects of Sowing Dates on Leaf Development Characteristics of Summer Maize(Zea mays L.)

[目的]探究播期影响玉米(Zea mays L.)产量形成的物质基础。[方法]在6.0万、7.5万株/hm2播种密度下探讨播期对玉米叶片生长发育特性的影响。[结果]随着播期的推迟,穗位叶及其以上叶片的展开速度加快,13叶期以后各阶段的叶面积指数显著减小,吐丝期及以后各时期叶片中叶绿素含量显著降低。[结论]播期调整导致的叶片发育程度的差异是播期影响玉米产量形成的关键原因之一,可以通过农事活动的适时调整,降低夏玉米晚播引起的产量损失。

[ Objective ] The aim was to explore the material basis of sowing date on influencing maize yield formation. [ Method ] The effects of sowing dates on maize leaf development characteristics under two densities（60000 and 75000 plants/hm2） were discussed. [ Result~ With delaying of sowing date, the developing rate of the ear-leaf and the leaf above it were accelerated, their leaf area index decreased significantly after 13-leaf stage, their chlorophyll content reduced at the silking stage and all the later stages. [ Conclusion ] The changes of leaf develop- ment due to sowing dates adjustment is one of the key reason that sowing date influences the maize yield formation, the yield loss of summer maize due to the late sowing reduces by farming activities adjusting timely.