Authors

Abstract

High breakage rate is the bottleneck that restricts corn grain mechanical harvesting in double-cropping area in China. The moisture content and compression resistance characteristics of corn grain have important effects on the breakage rate at threshing. In this paper, 5 corn varieties planted in double cropping area were selected and the effects of grain moisture content and compression resistance characteristics on threshed breakage rate were studied. Results showed that both the grains moisture content and the compression resistance characteristics had effects on the threshed breakage rate. The lower the moisture content, the greater the force required for breakage, and the more difficult it was to break. Meanwhile the breakage rate was also related to the displacement during pressing. The smaller the displacement, the lower the breakage rate, but if the displacement was too small, the corn was a silty variety and the breakage rate was still high. When the moisture content was 33%±1%, the threshing verification test showed that the average breakage rate of DH605, LY296 and KN21 was 5.39%, 5.02% and 7.13%, respectively, which was not suitable for grain mechanical harvesting under high moisture content (moisture content higher than 30%). However, the average breakage rate of LK868 and LD6018 was 4.76% and 4.25% respectively, which was suitable for grain mechanical harvesting under high moisture content. This research could provide a reference for corn varieties selection suitable for mechanical kernel harvesting in double cropping area.

Abstract in Chinese

脱粒破碎高是制约中国两熟区玉米机械粒收的瓶颈，玉米籽粒的含水率及抗压特性对脱粒破碎率有重要影响。本研究选取两熟区种植较多的5个夏玉米品种，研究籽粒含水率及抗压特性对脱粒破碎率的影响。结果表明，籽粒含水率及抗压特性均对脱粒破碎率产生影响，籽粒含水率越低，破碎时所需的力越大，越不易破碎;同时破碎率也与破碎时的位移有关，位移越稳定，破碎率越低，但位移太小时，玉米可能为粉质品种，破碎率仍较高。在含水率为33%±1%时，进行脱粒验证试验，得到DH605、LY296和KN21的平均破碎率分别为5.39%、5.02%和7.13%，不适宜高含水率（含水率大于30%）机械粒收；LK868与LD6018的平均破碎率分别为4.76%和4.25%，适宜高含水率机械粒收。本研究为两熟区筛选适宜机械粒收的玉米品种提供了参考。