1 玉米杂交种应用主要问题 1·1 选育推广速度滞后。玉米杂交新品种的选育主要由农业科研育种单位承担。由于三江平原应用的杂交种活动积温多在2300～2600℃,属中熟品种,多数杂交种由当地的科研单位育成,血缘比较单一,适应性差;加之区域封闭,障碍了其它适宜杂交种在该区的推广,造成同一生产水平的杂交种的推广速度滞后2～3年,进而影响玉米产量水平的提高。 1·2 品种数量多、质量差。近几年来玉米价格高,市场看好,农民种植玉米的积极性高涨,玉米杂交种的繁 1 maize hybrids main problems 1.1 The speed of breeding promotion lag. Breeding of new varieties of hybrid corn is mainly undertaken by agricultural research and breeding units. As the active accumulated temperature of the hybrids used in the Sanjiang Plain is mostly between 2300 and 2600 ℃, most of the hybrids are matured from local research institutes. The blood relatives are single and have poor adaptability. In addition, the closed area hinders other suitable hybrids in this area The popularization of the region, resulting in the same level of production of hybrid promotion speed lag 2-3 years, thereby affecting the improvement of corn production levels. 1.2 Variety, poor quality. In recent years, corn prices are high, the market is optimistic, the enthusiasm of farmers planting corn is high, and the complexity of corn hybrids