豫玉 12 (新黄单 90 4 )由河南省新乡市农科所 1989年育成 ,组合 4 78×京 7黄。该品种属中熟品种 ,需≥ 10℃积温 2 50 0℃左右。 1990～ 1993年在各级产量试验中表现高产、稳产、优质、多抗 ,在省、国家区试及生产示范中 ,产量获三个第一名。适宜在我国各主要玉米产区种植。种植密度一般以每公顷 6万株为宜 ,高产攻关田公顷 6 75～ 7 5万株为宜。制种时 ,母本早播 4～ 5天 ,父母本行比以 1:4～ 6为宜。已采用不育系改良配套模式制种 ,效果明显 Yu Yu 12 (Xin Huang Dan 90 4) by the Henan Province Xinxiang City Institute of Agriculture bred in 1989, a combination of 4 78 × Beijing 7 yellow. The variety is a medium-maturing varieties, need ≥ 10 ℃ accumulated temperature 2 50 0 ℃. From 1990 to 1993, it showed high yield, stable yield, high quality and multi-resistance at all levels of yield test. In the provincial and national district test and production demonstration, the output was ranked first in three categories. Suitable for planting in all major maize producing areas in China. Planting density is generally 60,000 per hectare is appropriate, high-yielding fields Tian He 6 675 ~ 75 000 is appropriate. Seed production, the mother of the early sowing 4 to 5 days, the parents than the line 1: 4 ~ 6 is appropriate. Sterile lines have been used to improve matching seed production, the effect is obvious