播期与密度对玉米物质生产及产量形成的影响

以郑单958为试验材料,研究播期与密度对玉米物质生产及产量形成的影响。结果表明,播期与密度和玉米群体干物质积累关系紧密,早播密植、晚播稀植有利于群体干物质积累;随播期推迟,产量呈下降趋势,且播期越晚,产量下降越显著。产量构成因素对产量的贡献率因气象条件而异,穗数和千粒重对产量贡献率较大,且随播期推迟均有所降低;花前充足的光辐射、花期适量的降水及花后适宜的有效积温对玉米产量有明显促进作用。苗后50~60 d的光辐射对穗数影响极显著,光辐射及降雨量与穗粒数也呈显著正相关;苗后70 d至成熟期的有效积温对千粒重影响显著。因此,适当调节播期,使玉米生长发育的关键时期处于最适的气象条件有利于发挥玉米高产潜力。

Effect of Matter Production and Yield Formation on Sowing Date and Density in Maize

ZD958 was used as the experimental material,the effects of matter production and yield formation on sowing date and density in maize were studied.The results showed that sowing date and density had a tightness relationship with group dry matter accumulation in maize,and early sowing with thick planting,late sowing with thin planting were beneficial to group dry matter accumulation.Yield was decreased with sowing date delayed,and the later the sowing,the significant the yield decreased.The difference of contribution rate for yield on yield composition was due to meteorological condition.Ear number and thousand kernel weight had a greater contribution rate on yield,and both reduced with sowing date delayed.Adequate light radiation before anthesis,timely rainfall in anthesis,suitable effective accumulated temperature after anthesis had an obvious auxo-action on maize yield.Light radiation had an extreme effect on ear numbers after emergence 50-60 days.Light radiation and rainfall had a positive correlation with kernels per ear during this period,and effective accumulated temperature had a significant effect on a thousand kernel weight between days after emergence 70 days and maturity.Therefore,taking full advantage of climatic resources,fair adjustment of sowing dates,making the critical period of maize growth and development in optimal meteorological condition,were beneficial to develop high yield potential of maize.