种子质量对中国玉米产出的影响

推动玉米持续增产的核心是主攻单产，而影响单产的诸多因素中，种子质量的提升至关重要。采用玉米主产区20个省（市）2002—2012年的分省数据，实证评估了种子质量改进对中国玉米单位产出的影响。采用两种种子质量评估指标的估计结果均表明，种子质量水平的提升显著地促进玉米单位产出的增加，但是品种质量改善的促进作用近年有所弱化。因此，应大力支持优良新品种选育，健全生产质量标准体系，提高种子品种和生产质量，并通过健全社会化技术服务体系，加快农户品种选用的更新换代。

The Effect of Seeds Quality Improvement on Maize Yield

The core of the continuous increase of output lies on yield which is essentially affected by seed quality among many factors. This paper, using the data covering 20 key maize-producing provinces in China, empirically investigates the impact of seed quality improvement on maize yield. It is revealed, by using two measurements on seed quality, that maize yield is significantly positively affected by seed quality, but the positive effect of varieties improvement has weakened in more recent years. Therefore, some measures, including promoting the breed of new fine varieties, improving the system of seed production quality standard and strengthening the agricultural technology services system, should be taken to improve the varietal and production quality of maize seeds as well accelerate the update and replacement of varieties adopted by farmers.