玉米生理成熟后田间脱水期间的籽粒重量与含水率变化

摘要

[目的]黄淮海夏播玉米区收获期偏早、籽粒含水率普遍偏高,制约了机械粒收的收获质量,延期收获能够降低收获期籽粒含水率,但是该过程是否因籽粒重量下降造成产量损失尚不明确.本文开展玉米生理成熟后田间站秆脱水期间籽粒含水率与粒重变化情况研究,为机械粒收技术的推广应用提供依据.[方法]本研究于2015年和2016年在河南新乡中国农业科学院综合试验站进行,选择22个当前主要种植品种为供试材料,采取统一授粉,连续测定籽粒重量与籽粒含水率变化.其中,2015年授粉后26 d开始测定,生理成熟后26-52 d结束;2016年授粉后11 d开始测定,生理成熟后16-35 d结束.分析生理成熟后田间脱水期间籽粒含水率与粒重变化.[结果]22个参试品种生理成熟期百粒干重为23.3-37.4 g,平均为30.8 g;籽粒含水率为21.5％-33.1％,平均为27.5％. 22个品种生理成熟后分别经过16-52 d田间站秆晾晒后,百粒干重为22.9-38.4 g,平均为32.0g;籽粒含水率为12.9％-24.4％,平均为17.3％.生理成熟前籽粒重量随着授粉后天数增加而逐渐增加,不同测试时期之间存在显著差异;生理成熟后随着田间站秆时间延长,籽粒含水率变化呈极显著下降趋势,而籽粒重量未表现出显著变化,不同熟期品种和不同年份结果表现一致;生理成熟后籽粒重量与籽粒含水率之间不存在显著相关关系.[结论]黄淮海夏玉米生理成熟后田间站秆晾晒脱水期间,籽粒含水率显著下降,而籽粒重量并未发生显著变化,延期收获降低了籽粒含水率,并且不会因粒重下降造成产量损失.%[Objective] In Huang-huai-hai Plain,the earlier harvesting date and the higher grain moisture content of summer maize reduces the harvest quality of mechanical grain harvest technology.The delayed harvest can reduce the grain moisture content.It remains unknown whether the grain weight and the yield will decrease or not during the field drying process.Clearing the changes of maize grain moisture and grain weight after physiological maturity is of benefit to promoting the application of grain mechanical harvesting technology.[Method] In 2015 and 2016,twenty two mainly planted cultivars were investigated in Comprehensive Experiment Stations of Chinese Academy of Agricultural Sciences located in Xinxiang,Henan.Controlled pollination was applied in every cultivar.In 2015,from the 26th day after pollination to the 26th-52th day after physiological maturity,the grain weight and grain moisture were measured to analyze their changes.In 2016,the same traits were measured from the 11th day after pollination to the 16th-35th day after physiological maturity.[Result] Results showed that the average 100-kernel dry weight was 30.8 g at physiological maturity ranging from 23.3 g to 37.4 g.The average kernel moisture content was 27.5％ at physiological maturity ranging from 21.5％ to 33.1％.When all cultivars were finally tested after the long drying-down in field,the average 100-kernel dry weight was 32.0 g ranging from 22.9 g to 38.4g and the average kernel moisture content was 17.3％ ranged from 12.9％ to 24.4％.Before physiological maturity,the kernel weight increased significantly with the days after pollination.After physiological maturity,the kernel moisture content reduced significantly while the kernel weight kept stable.There was no statistically significant correlation between the kernel moisture content and the kernel weight after physiological maturity.[Conclusion] In Huang-huai-hai Plain,during the drying-down in field,com kernel moisture content reduced significantly after physiological maturity while kernel dry weight was stable.The delayed harvest is of help for lower kernel moisture content and can't decrease the yield due to the loss of kernel weight.