基于分期播种试验夏玉米延迟收获促进子粒灌浆和粒重增益效应

基于2019-2022年夏玉米播期试验资料，分析夏玉米生理成熟后延迟收获对子粒农艺性状改善、增产效应。结果表明，早播10 d至晚播20 d处理的有效灌浆结束日均比生理成熟期延后，子粒有效灌浆持续日数依次比其花后10 d至生理成熟期日数延长28～9 d，播期每推迟10 d延长日数减少6.3 d。子粒农艺性状有明显的改善，百粒重、穗粒重提高，子粒增产效应明显，理论产量增产率16.95%～7.66%，增产量1 960.36～681.51 kg/hm²，对照增产最多，比晚播10、20 d增产粮食多2.4～2.9倍。为华北地区提高气候资源利用效率和粮食生产提质增效提供参考。

Delayed Harvest of Summer Maize Promoted Grain Filling and Yield Gain Based on Different Sowing Date Experiments

Based on the different sowing date experiments data of summer maize from 2019 to 2022, the effects of delayed harvest after physiological maturity of summer maize at different sowing dates on grain agronomic traits improvement and yield increase were analyzed. The results showed that the effective grain filling end date of 10 d early sowing to 20 d late sowing is delayed than the physiological maturity, the duration of effective grain filling days is 28~9 d longer than that from 10 d after flowering to physiological maturity, the number of extended days decreased by 6.3 d for every 10 d delay in sowing date,the agronomic characters of grain were improved obviously, 100-grain weight and grain weight per spike were increased. The theoretical yield increased rate by 16.95%-7.66%, yield increased by 1 960.36-681.51 kg/ha, the control yield increased the most, and the grain yield increased by 2.4-2.9 times than that of late sowing 10 d and 20 d. The results provide a reference for improve the efficiency of climate resource utilization, and enhance the quality and efficiency of food production in North China.