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“河北杨”又名串根杨,其树干通直,树型优美,适应性强,生长迅速,材质良好,抗病虫害能力强,深受群众喜爱,是我区较好的先锋速生用材树种。在条件较好的地方,五年成椽,十年即可成檩。如我县北山林场有两株十八年生河北杨,高32米,胸径36厘米,而本地同龄青杨高为27米,胸径29厘米。更重要的是:青杨病虫危害严重,95％以上枝干多为天牛钻透,不能成材,但河北杨迄今未发现任何病虫害。河北杨虽具很多优点,但其繁殖却受限甚大。在有性杂交中,它的雄株难寻,和其他杨树杂交时,不孕性强。我们搞了二年有性杂交,没有进展。在无性繁殖的七年试验中,虽然数量不多,但已具有一定的发根力。截至今年,成活率达80.9％。现将试验初报如下。
“Hebei Yang,” also known as the string root Yang, the trunk straight, beautiful trees, adaptability, rapid growth, good material, pest-resistant ability, loved by the masses, is our region a good pioneer in growing timber species. In better conditions, five years into rafters, ten years can be successful. For example, there are two eighteen-year-old Hebei poplars in Beishan Forest Farm in our county, with a height of 32 meters and a breast diameter of 36 centimeters. The young Populus euphratica with the same age is 27 meters high and the diameter at breast height is 29 centimeters. More important is: Qingyang pests and diseases endanger the serious, more than 95% of the branches and more for the daydragon drilled, can not be turned into a timber, but Yang Yang, Hebei Province so far found no pests and diseases. Although Hebei Yang has many advantages, but its reproduction is limited. Sexual hybrids, its male hard to find, and other poplar hybridization, strong infertility. We did sexual intercourse for two years and did not make any progress. In a seven-year trial of asexual reproduction, although a small number, it has had some hair rooting power. As of this year, the survival rate of 80.9%. Now the first report is as follows.