[关键词]
[摘要]
玉米收获期籽粒含水量普遍偏高,制约着当前机械粒收技术的应用。本研究选择7个不同类型春玉米品种,通过对灌浆期籽粒乳线和含水量、籽粒重量的连续测定,明确乳线与籽粒水分、籽粒水分与授粉后积温的关系,为适宜机械粒收品种筛选提供依据。研究结果表明,7个参试品种授粉至生理成熟天数、积温需求和百粒重差异明显,灌浆后45d乳线下移到籽粒62.4~76.2%处,62~70d乳线先后消失。随着乳线下移籽粒含水率呈明显的直线下降趋势,生理成熟前、后品种之间籽粒脱水速率差异显著,乳线比例可以预测籽粒水分和灌浆天数变化,生理成熟后达到低水分粒收要求所需天数在品种间均可相差1倍。参试品种籽粒含水率与授粉后积温均符合 Logistic Power 非线性增长模型。授粉后,7个品种籽粒含水率降低到机械收获籽粒含水率25%时,各品种所需授粉后积温1298.6~1463.2℃.d,平均1375.7℃.d,品种间相差164.6℃.d;达到22%~18%籽粒含水率时,授粉后积温品种之间为1414.8~1827.9℃.d,相差413.1℃.d。综合考虑品种熟期、籽粒乳线和水分变化、灌浆期脱水进程及对应热量匹配,MC703、先玉335和陕单650是适宜机械粒收的中晚熟品种,可推迟到10月上旬收获,九圣禾2468、联创825、瑞普909等是适宜机械粒收的晚熟品种,可推迟到10月中下旬收获。因此,选择生理成熟后脱水快和收获期籽粒水分低的品种,延期收获降低水分含量是提高西北春玉米粒收质量的关键。
[Key word]
[Abstract]
The moisture content of grains during corn harvest period is generally high, which restricts the application of current mechanical grain harvesting technology. The experiment was carried out with seven corn varieties selected by continuously measurement of grain milk line, water content and grain weight during filling period, to clarify the relationship between milk line and grain moisture, grain moisture and accumulated temperature after pollination. Provide a basis for the selection of suitable mechanical grain harvest varieties for selecting varieties suitable for mechanical harvesting of grains.The results showed that the days from pollination to physiological maturity, accumulated temperature requirements, and 100-kernel weights of the seven varieties tested were significantly different. The milk lines moved down to 62.4 ~ 76.2% at 45d after grouting, and disappeared at 62-70d after grouting. The grain moisture content showed a clear linear downward trend, while the milk line moving downward. There was a significant difference in grain dehydration rate among varieties before and after physiological maturity. The ratio of the milk line can predict the changes of grain moisture and filling days. The difference of the time it took that grain moisture content of the tested varieties reduced the requirements of mechanical grain harvesting since physiological was doubled. The grain moisture content of the tested cultivars and the accumulated temperature after pollination are consistent with the Logistic Power nonlinear growth model. The grain moisture dropped to 25% , 22% and 18% when the accumulated temperature after pollination reached average 1375.7°C?d, 1493.2°C?d and 1687.3°C?d , changing from 1298.6 °C?d to 1463.2 °C?d, 1414.8°C?d to 1600°C?d and 1594.8°C?d to 1827.9°C?d between cultivars. Comprehensively considering the maturity time, change of grain milk line and moisture, dehydration process and accumulated temperature after pollination required, MC703, XY335 and SD650 are suitable mid- late-maturing cultivars and JSH2468,LC825 and RP909 are suitable late-maturing cultivars for mechanical grain harvesting, that the harvesting time can be delayed until early October and mid-late October respectively. Therefore, selecting varieties with fast dehydration after physiological maturity and low grain moisture during the harvest period, delaying harvest and reducing moisture content are the key to improving the quality of spring corn harvest in Northwest China.
[中图分类号]
S513
[基金项目]
西北玉米新品种配套技术集成与示范(2018YFD0100206)、农业部玉米产业技术体系(CARS-02-66)