温光生态效应对春玉米物质生产的影响

为进一步优化北京地区的春玉米生产,通过设计不同的播期,研究了不同温光生态条件与玉米物质生产的关系。结果表明,当播期从4月底推迟至5月底时:春玉米平均增产17.6%,穗粒数增加了15.4%,而千粒重增加4.3%;玉米灌浆中期(吐丝后16—45 d)和后期(吐丝后46 d—成熟)的光温状况得到明显的改善,主要表现在日均光辐射强度得到一定程度的提高(3.6%和10%),日均温明显下降(1.7和4.3℃),日均温差则明显增加(4.3和3.1℃)。相关分析表明,灌浆中后期日辐射量以及日温差的增大是推迟播期后春玉米增产的主要气候因素。灌浆中后期日均温的降低和日温差的增大,在一定程度上延长了春玉米的绿叶持续期,同时有利于加强后期的光合势,主要表现在成熟期LAI的增大。另外,推迟播期后,大喇叭口期至乳熟期干物质积累速率的增加与穗粒数有着密切的关系,而前者的增加主要得益于营养生长期相对较高的日均温。

Effect of temperature and solar ecological factors on spring maize production

The relationship between temperature-solar condition and maize growth was studied by designing different sowing dates.Results showed that the grain yield of spring maize could be enhanced 17.6% by delaying sowing date from the end of April to the end of May.For the yield components,the advantage of sowing at the end of May was mainly observed for kernel number,which increased about 15.4%.Improvement of temperature and solar condition during middle-late grain-filling period is the main reason for yield incre...