中文摘要：

试验选用玉米杂交种郑单958（ZD958）和隆平206（LP206）为材料，分别于6月9日（PDⅠ）、6月17日（PDⅡ）和6月26日（PDⅢ）等3个时期播种，比较研究了玉米产量、籽粒灌浆特性及籽粒生长期间主要气象因子的变化。结果表明，中期播种的玉米籽粒产量最高，早播处理次之，晚播处理产量最低。PDⅡ籽粒启动势和灌浆持续期显著高于PDⅠ，同时PDⅡ籽粒平均灌浆速率和最大灌浆速率显著高于PDⅢ。可见，播期主要通过籽粒灌浆启动时间的早晚、灌浆速率的高低以及灌浆持续时间的长短影响籽粒生长。籽粒灌浆期间有效积温与平均灌浆速率呈显著正相关，而平均日温差与启动势呈显著正相关。说明玉米籽粒生长期间有效积温不足是晚播玉米减产的主要因素，而早播主要是灌浆期间平均日温差较低造成的。沿淮地区玉米生长的适宜播期在6月17日左右。

英文摘要：

In order to investigate grain yield, grain filling characteristics of summer maize, and main meteorologi- cal factors during grain filling under different planting date, two maize hybrids, Zhengdan 958 and Longpin 206, were planted in Fengyang （32°51′N, 117°33′E） with three planting date （9 （PDⅠ ）, 17 （PDⅡ ）, and 26 （PDⅢ） June in 2011 and 2012） in this study. The results showed that there was significant effect of planting date on grain yield. The grain yield had great difference in treatments, and the trend as was follows： PD 〉 PD 〉 PD Ⅲ. Simulating the process of the grain growth in different treatments with Logistic Equation showed that initia- ting accumulation and grain filling duration of PDⅡ were significantly higher than that of PDⅠ , and average and peak grain filling rate of PDⅡ were significantly higher than that of PD Ⅲ. It showed that it was mean filling rate, grain filling duration and initiating time that determined grain growth. Remarkable positive correlation was found between effective accumulated temperature and mean grain filling rate, and there was a significant positive correlation between mean diurnal temperature and initiating accumulation. It showed that the low grain yield of PDⅠ and PDⅢ was likely to prolong the low diurnal temperature （PDⅠ ）, and low effective accumulated tem- perature （PDⅢ ） was compared with PDⅡ treatment. The present study showed that the suitable sowing date was about 17 June in Huaihe River region.