云龙县杂交玉米推广一步到位云龙县农业局６７２７００杨勤１９９６年云龙县大力推广杂交玉米，推广面积由１９９５年的５．２８万亩扩大到１４．２８万亩，实现全县玉米生产基本杂交种化。全县玉米平均亩产由１４３．２千克提高到２３４．２千克，提高９１千克；玉米总产... Yunlong County, one step to promote hybrid corn Yunlong County Bureau of Agriculture 672700 Yang Qin Yunlong County in 1996 to promote hybrid corn, the promotion of the area from 52,800 acres in 1995 expanded to 142,800 acres, the county achieved basic hybrid corn production The The county’s average yield per mu from 143.2 kg to 234.2 kg, an increase of 91 kg;