我国《农作物种子质量标准》规定:杂交玉米种子以品种纯度指标为划分种子质量级别的依据。主要的四项检测指标(水分、净度、发芽率、纯度)中,有一项指标达不到国家标准,即为不合格种子,禁止进入市场销售。2005年,农业部对杂交玉米种子的质量监督抽查结果显示,在抽查的85家企业的144个样品中,合格样品123个,合格率为85.4%。从抽查检测结果看,四项指标中的前三项种子净度、发芽率、水分合格率均在98%以上,远远高于纯度的合格率86.8%。由此可见,纯度是目前杂交玉米种子质量控制的关键。笔者认为,杂交玉米种子纯度的控制主要有以下几个重要技术环节: China’s “crop seed quality standards” provides: hybrid corn seed purity index to determine the basis of the quality level of the seed. The main four indicators (moisture, clarity, germination, purity), there is an indicator of less than the national standard, that is, non-qualified seeds, prohibit the entry into the market. In 2005, the quality supervision and spot check of hybrid corn seeds by the Ministry of Agriculture showed that of 144 samples sampled from 85 enterprises, there were 123 qualified samples with a pass rate of 85.4%. From the sampling test results, the first three indicators of the four indicators of clarity, germination rate, water pass rate of more than 98%, much higher than the purity of 86.8% pass rate. Thus, purity is the key to the quality control of hybrid corn seeds. The author believes that the control of hybrid corn seed purity mainly in the following several important technical aspects: