在夏直播地区配制玉米杂交种，由于受到许多不利因素的影响，往往产量低，质量差。１９９３～１９９８年，我们通过连续六年大面积集中连片杂交玉米制种，摸索出一套切实可行的高产量高质量制种技术。１　选用有增产潜力的“双高”紧凑型品种制种。“双高”是指制种产量高和大 The preparation of maize hybrids in summer seeding areas is often characterized by low yields and poor quality due to many unfavorable factors. From 1993 to 1998, we explored a set of feasible high-yielding and high-quality seed production techniques by concentrating large-area contiguous hybrid corn seed production for six consecutive years. 1 Selection of production potential with the “double high” compact varieties of seed. “Double high” means seed production is high and large