Authors

Abstract

This study addressed the issue of high grain breakage rates during mechanical maize harvesting, which significantly compromise grain quality and subsequent storage performance. A comparison was conducted between maize subjected to natural dehydration (CK) and maize treated with a desiccant (SY). The research analysed the moisture content of various plant organs, grain starch composition, and puncture resistance characteristics across three kernel regions during maturation. The results revealed a strong positive correlation between the grain dehydration rate and moisture loss in both the stalk and cob. Desiccant application accelerated grain dehydration and promoted the conversion of branched-chain starch. In both treatments, decreasing kernel moisture content led to the development of a thicker and denser internal cuticle layer, which increased the yield load and elastic modulus in the lateral and apical kernel regions. When kernel moisture content dropped below 25%, the SY group exhibited significantly higher yield load and elastic modulus than the CK group. These findings provide a theoretical foundation for improving kernel impact resistance and reducing grain breakage during mechanical harvesting.

Abstract in Chinese

针对玉米机械粒收中籽粒高破碎率问题，本研究以东单808为对象，监测自然脱水（CK）与脱水剂施用(SY)下玉米植株各器官水分、籽粒淀粉含量、籽粒三个部位的膜穿刺变化。结果表明，籽粒脱水速率与穗杆、穗轴同步。施用脱水剂缩短了玉米籽粒含水率降至25%的时间（3.09 d），加快支链淀粉的转化过程。当籽粒含水率降至25%以下时，屈服载荷与弹性模量SY组>CK组。同组之间，随着籽粒含水率的减少，内部角质层、致密性增加，三个部位弹性模量增大，侧部和顶部的屈服载荷增加。综上，脱水剂可加快生理成熟后期玉米籽粒的脱水，提高机械收获时的抗打击性能。