播期对河套地区玉米灌浆进度的影响

旨在为玉米的高产栽培提供理论支撑。采用分期播种法,利用试验数据,建立28个生长模型（方程均通过0.01的极显著检验）,将玉米灌浆期百粒干重、百粒体积随灌浆日数增加的时段分为三阶段,即渐增期、快增期和缓增期。适时播种的玉米吐丝后百粒体积、百粒干重增加进入渐增期,终止日分别为吐丝后的6天和20天,此后进入快速增长期,时间分别为22天和18天;其后到籽粒体积和干重增加进入缓慢增长期。适时播种的玉米百粒干重增加逐渐增长期为吐丝后活动积温区间0~502.4℃·d,增幅0.014 g/℃·d;快速增长期为吐丝后活动积温区间502.4~938.4℃·d,增幅0.049 g/℃·d;缓慢增长期为吐丝后活动积温区间938.4~1355.1℃·d,增幅0.018 g/℃·d。

Sowing Date Affects Grain Filling Progress of Maize in Hetao Area

To cultivate high yield maize, based on the experimental data of sowing by stages, 28 growth models of maize were established (all Logistic equations passed the extremely significant test of 0.01). The growth periods of 100-kernel weight and 100-kernel volume increasing along with the grain filling days were divided into three stages, namely the gradual-increase period, the rapid-increase period and the slight-increase period. In the timely sowing maize, 100-kernel volume and 100-kernel weight entered gradual-increase period after silking, and the ending day was the 6th day and the 20th day, respectively; and then they entered the rapid-increase period, the ending day was the 22nd day and the 18th day, respectively; after that, the grain volume and weight entered the slight-increase period. The gradual-increase period of 100-kernel weight of timely sowing maize was in the active accumulated temperature interval of 0-502.4°C·d after silking, increased by 0.014 g/°C·d; the rapid-increase period was in the active accumulated temperature interval of 502.4- 938.4°C·d after silking, increased by 0.049 g/°C·d; slight-increase period was in the active accumulated temperature interval of 938.4-1355.1°C·d after silking, increased by 0.018 g/°C·d.