播期对不同玉米品种生长发育及产量的影响

通过调整播期，研究影响玉米生长发育和产量形成的气候因素，尤其是高温条件。试验选取京农科728、登海618、郑单958和先玉335共4个主栽玉米品种为材料，分别在2019年6月5日（T1）、6月15日（T2）和6月25日（T3）3个播期处理种植。结果表明，4个玉米品种的生育期，随着播期的推迟均不同程度延长。成熟期干物质积累量，4个玉米品种的叶片和茎秆在不同的播期没有明显差别，但籽粒和穗4个品种干物质积累量早播处理比晚播处理积累量大，可能是因为早播处理比晚播处理时段的温度要高。在玉米穗粒数、百粒质量和产量上，品种和播期处理对其影响达极显著水平。品种和播期处理对穗粒数、百粒质量和产量表现出极显著的交互作用。京农科728、登海618、郑单958和先玉335品种的穗粒数、百粒质量和产量最大值均为T2处理，最低均为T1处理，在产量性状上可能是因为T1处理在开花授粉阶段正好遇到连续高温天气，导致T1处理结实性较差。由此可见，在玉米生长发育和产量形成时，高温对其影响较大，在没有遇到高温的情况下，适时早播对玉米产量的提高将更有利。 

Effect of Sowing Date on Growth，Development and Yield of Different Maize Varieties

Climatic factors，especially high temperature，affecting growth，development and yield formation of maize were studied by adjusting sowing date.In this experiment，four main planted maize varieties of Jingnongke 728，Denghai 618，Zhengdan 958 and Xianyu 335 were selected as materials and planted at three sowing dates of June 5（T1），June 15（T2）and June 25（T3）in 2019，respectively.Results showed that growth periods of four maize varieties were prolonged with postponement of sowing date.In terms of dry matter accumulation at maturity stage，there was no significant difference between leaves and stems of four maize varieties at different sowing dates，but dry matter accumulation of seeds and ears were higher in early sowing treatment than in late sowing treatment，possible reason was temperature in early sowing treatment was higher than that in late sowing treatment.In terms of kernel number per ear，weight per hundred grains and yield，variety and sowing date had a significant effect on yield.Variety and sowing date had significant interaction with grain number per ear，weight per hundred grains and yield.Jingnongke 728，Denghai 618，Zhengdan 958 and Xianyu 335 four varieties of spike grain number，hundred kernel weight and yield were T2 processing，maximum minimum were T1 treatment，possible reason was T1 treatment on yield traits in flowering pollination stage were confronted continuous high temperature weather，lead to T1 with strong sex was bad.So，in maize growth and yield formation，high temperature has a great influence on it.In absence of high temperatures，timely early sowing would be more beneficial to increase of corn yield.