中文摘要：

机械粒收是玉米收获技术发展的方向,是玉米实现全程机械化、转变生产方式的关键。当前,籽粒收获过程中破碎率高的问题不仅降低玉米等级和销售价格,而且导致收获产量下降,并增大烘干成本、增加安全贮藏的难度,是推广机械粒收技术面临的重要问题。玉米不同基因型间籽粒破碎率存在显著差异,抗破碎特性是可遗传的性状,可通过育种培育抗破碎率的品种;不同收获机械和作业参数对籽粒破碎率有显著影响,选择轴流式收获机,并根据玉米生长、成熟和籽粒含水率状况及时检查与调试收获机参数是保证低破碎率的有效措施;生态环境因素对破碎率也有显著的影响,籽粒形成、自然干燥和收获期的光照、温度、湿度等因素均会影响到籽粒硬度、容重、含水率和质地等与籽粒破碎相关的特性;种植密度、水肥管理、收获时期等栽培管理措施对籽粒破碎率也会产生明显的影响。因此,针对不同区域生态环境条件,应选择适宜生育期内能与当地光温资源匹配的品种以及确定品种适宜的种植区域。合理种植密度、优化氮肥管理和适量灌溉有利于降低破碎率,而选择在最佳收获期收获是降低籽粒破碎率的最有效措施。

英文摘要：

Mechanical grain harvesting is the developing direction of maize harvesting technology.It is the key technology to realize entire mechanization of maize production and change the mode of production.At present,the high kernel broken rate of maize harvesting not only lowers the grade of corn but also reduce corn sales price.Moreover,it leads to the decline of maize yield and increases the cost of grain artificial drying,and increases the difficulty of safe storage of maize.Therefore,high broken rate is the major problem that we are facing to popularize grain mechanical harvesting techniques.Kernel broken rates of different genotypes of maize differ significantly.As the resistance to kernel broken is a heritable trait,the anti-breaking maize varieties can be bred.Because of the significant influence that harvest machines and operational parameters have on kernel broken rates,it is also an effective measure to ensure low broken rate by choosing rotary（axial-flow） combines and adjusting its parameters according to the plants growth condition,maturity and moisture content of maize kernel.In addition,ecological environment also has significant influences on broken rates of grain.The factors of sunshine times,atmospheric temperature,relative humidity,and so on in the process of grain filling,natural drying,and harvesting period will affect the characters associated with kernel broken such as grain hardness,test weight and kernel moisture content.Hence,according to ecological conditions in different regions,it is necessary to choose maize varieties which can match the local light and temperature conditions in the suitable growth period of maize,and to determine the suitable planting area for those maize varieties.Cultivation managing measures such as planting density,management of irrigation and fertilizers,harvesting time have obvious influences on kernel broken rates.Reasonable planting density,optimized nitrogen fertilizers management and moderate irrigation make for the reduction of broken kernels,and the most eff