根据我场9年来毛白杨的育苗经验和近两年来的试验研究材料,我们认为提高毛白杨育苗(埋条和插条育苗)成活率的基本因素有三个。一、选择座地条不同枝条来源与育苗成活率和产苗量有显著的关系。例如,1964年用树头条埋条育苗,亩产仅810株,而用座地条埋条育苗则亩产达3950株;又如1965年用 According to the field poplar breeding experiences in the past nine years and the experimental research materials in the past two years, we think there are three basic factors to improve the survival rate of poplar seedlings (buried strips and cuttings). First, the choice of different branches of the ground source of seedling survival rate and seedling production have a significant relationship. For example, in 1964, tree nurseries were planted with trees, with a yield of 810 plants per mu, while 3950 plants were nurtured with strips of strips. In 1965,