不同收获期对玉米子粒机械收获质量及产量的影响

以山西子粒机收主推的4个品种金科玉3306、迪卡517、中地88、DF607为研究对象，生理成熟后设置不同收获期，研究玉米不同收获期对子粒机械收获质量(子粒破碎率、含杂率、落粒率、落穗率、总损失率)及产量的影响。结果表明，子粒收获质量中含杂率、总损失率分别为1.57%、1.75%，均满足《玉米收获机械(GB/T21962-2020)》标准要求；破碎率为5.46%，是子粒机械收获质量的主要问题，不同收获期对机收产量影响不显著。含水率随着收获期的推迟而降低，含水率高是导致破碎率高的主要因素。结合两年不同收获期，通过拟合方程可以得出，含水率与破碎率呈二次曲线关系，当含水率在19.0%～24.3%时，破碎率低于5%。根据不同收获期子粒含水率的变化规律，该区域子粒机械收获以10月15～20日为宜。供试玉米品种中迪卡517、金科玉3306表现较好。

Effects of Different Harvesting Time on the Mechanical Harvest Quality and Yield of Maize Grains

The study investigated the effects of different harvesting times on the mechanical harvest quality(kernel breakage rate, foreign matter rate, grain loss during harvest, residual grain loss rate, and total loss rate) and yield of maize grains. Four varieties of maize including Jinkeyu3306, Dika517, Zhongdi88, and DF607 were used as the research objects which are suitable for mechanical grain harvesting in Shanxi. After physiological maturity, different harvesting times were set to study the harvest quality and yield. The results showed that impurity rate and total loss rate which are parts of mechanical harvesting quality were 1.57% and 1.75%, respectively, up to standard of Corn Combine Harvester(GB/T21962-2020), but grain brokage rate was 5.46%, which is the key question in mechanical harvest quality. Meanwhile mechanical harvesting yield in different harvesting time has little difference. Grain moisture content decreased with the delay of harvesting time, and high moisture content was the main factor leading to high brokage rate. Combined with the two-year different harvesting time, it can be seen from the fitting equation that there is a quadratic relationship between moisture content and brokage rate. When the moisture content is between 19% and 24.3%, the brokage rate is less than 5%. According to the variation of grain moisture content at different harvest time, the best time for mechanical grain harvesting in this region was from October 15 to 20. The tested varieties Dika517 and Jinkeyu 3306 performed well.