1因地制宜,合理安排制种品种在玉米杂交制种生产中,首先要根据当地的气侯条件、有效积温的高低以及历年早霜来临的时间、霜冻时间,确定安排合理生育期的品种。通过合理安排制种品种,使该制种品种能在早霜之前完全成熟,在霜冻之前 1, according to local conditions, a reasonable arrangement of seed varieties in the production of hybrid corn, first of all according to the local climate conditions, the effective level of accumulated temperature and early frost coming over the calendar year, frost time to determine the reasonable breeding period varieties. By reasonably arranging seed production, the seed can be fully matured before the early frost and before the frost