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由于种子品质的不同及经营管理水平的影响,苗木个体均以其质量指标值的大小,表现出质量上的差别,从而可将它们划分成若干质量近似的群体。同一群体中苗木质量标志值最近似,不同群体其质量标志值相差较大. 世界各国为保证壮苗用于植树造林,一般将出圃苗分为四级或五级,我国将苗木分为三级:Ⅰ、Ⅱ级苗为合格苗,即可用于造
Due to the difference of seed quality and the impact of management level, individuals of seedlings show the difference in quality according to the value of quality index, so they can be divided into several groups with similar quality. In the same group, the seedling quality mark value is the most similar, and different groups have different quality mark values.In order to ensure the strong seedlings are used for afforestation in different countries, the nursery stock is generally divided into four or five levels, and the seedlings in our country are divided into three levels : Ⅰ, Ⅱ seedlings for qualified vaccine, can be used to make