连续２ａ 对玉米夏播制种籽粒灌浆速度和收获期进行了研究，结果表明：淮北地区玉米夏播制种无论播期早晚，均表现授粉后１０ 天左右籽粒开始形成。快速增重的时间随播期推迟而延长，灌浆持续时间表现相同趋势。授粉后５５～６０ 天，即籽粒乳线消失达完全成熟时收获产量最高，比传统的苞叶变黄时收获推迟１２～１７ｄ，可增产１７．７％ ～２４．１％ 。 The results showed that in summer, the seeds of maize were planted in summer in Huaibei area, no matter the sowing date or not, the grains began to form about 10 days after pollination. The time of rapid weight gain was prolonged with the delay of sowing date, and the duration of filling showed the same tendency. 55 ~ 60 days after pollination, that is, when the grain milk disappeared completely ripe, the harvest yield was the highest, which was 12 ~ 17d later than the traditional bract yellowing, which increased by 17.7% ~ 24.1%.