1历史变迁1 1949~1957年以户留种阶段这一时期,我国农业生产的基本特点是,家家种田,户户留种,玉米种子工作的基本任务是发动群众繁殖推广增产潜力较大的良种。1950年2月,在山西省农业技术工作会议,提出了推广优良品种的任务;同年雁北专区试验场成立,大部分县建立了县农场。专区试验场以繁育推广为主,兼顾必要的试验研究;县农场以示范繁育推广为中心任务。这一时期主要推广由试验评选出的金皇后和雁农2号。其中金皇后成为河北省乃至北方 1 Historical changes 1 From 1949 to 1957, the period of household reservation in this period, the basic feature of agricultural production in our country is that every household has to grow their own farmland and every household needs to keep their seed. The basic task of working with corn seed is to mobilize the masses to promote their production and increase the potential for production. Good seed. In February 1950, at the conference of agricultural technology in Shanxi Province, the task of popularizing fine varieties was put forward. In the same year, the experimental field of Yanbei Prefecture was established and most counties set up county farms. Special test area to promote the main breeding, taking into account the necessary experimental study; county farms to promote the demonstration of breeding as the central task. During this period, Golden Queen and Yannong No. 2, which were selected by the trial, were mainly promoted. Among them, the Golden Queen became Hebei Province and even the north