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用优树后代苗木造林,是使树木生长快、材质好、成材早的重要措施。超级苗木具有早期优势遗传的表现,因此,选择超级苗木是研究早期选种的一个有效途径,对于林木良种选育有很重要意义。根据外地经验,结合我圃实际情况,1973年我们从杨树中选择了部分超级苗,其主要做法简介如下: 一、样地苗木生长调查由于苗木立地条件和密度等环境因子的差异,生长量不一。为选择准确,我们采取了机械抽样调查法,即每10行抽1调查样行,每样行两头5株不调查,地块两边的3畦不调查。每样行3株中调查1株,实测高与根径(南北、东西取平均值)。共调查加杨1,710株,沂南杨1,451株,毛白杨466株。
Afforestation with excellent trees offspring seedlings, is an important measure to make the trees grow fast, the material is good, and the timber is early. Super seedlings have the early superiority of genetic performance, therefore, the choice of super seedlings is an effective way to study the early selection of trees for seed selection is very important. According to the field experience, combined with the actual situation in our garden, in 1973 we selected some super seedlings from poplar, the main practices are as follows: First, the sample seedling growth survey site conditions and density of seedlings and other environmental factors, the growth of different . To choose accurately, we adopted a mechanical sampling survey method, that is, every 10 rows of 1 sample survey line, each sample line 5 does not investigate two sides, 3 plots on both sides of the survey does not. One sample of 3 strains was investigated in each sample. The measured height and root diameter (North-South, East-West, average). A total of 1,710 Populus euphratica, 1,451 Populus euphratica and 466 Populus tomentosa were investigated.