玉米是我省主要粮食作物之一,山区是玉米的重要产区。全省2,400多万亩玉米,盆周山区和川西南山区约占1,000万亩,其中,分布在海拔1,000米以上约400万亩。由于这些地区春迟秋早气温低,玉米生产常遭受四、九两月的低温冷害,往往是“种得早不出,种得迟不熟”。高产的杂交玉米良种也因生育期长,积温不足,上不了高山,至今仍是老品种当家,产量低而不稳。近年来,部分 Corn is one of the main grain crops in our province, and the mountainous area is an important producing area for corn. More than 2,400 mu of corn in the province, about 10 million mu of the mountainous area in the basin and the mountains in the southwest of Sichuan Province, of which about 4 million mu are above 1,000 meters above sea level. Due to the low temperature in late spring, autumn and early autumn in these areas, corn production often suffers from cold chilling injury in April and September, often resulting in “no early planting or late ripening.” High-yielding hybrid corn seed because of long growth period, lack of accumulated temperature, can not get on the mountain, is still the old breed, low yield and instability. In recent years, some