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二白杨(Populus nigra var thevestina×P.Simonii)是我省选出的优良天然杂种。在河西走廊一带栽培历史较久,是这里的主要造林树种。它干形高大,树形美观,生长较快,耐寒耐旱,也较耐盐碱。发芽早,落叶迟,生长期较长。因此,研究迅速发展二白杨,对于各场农田防保林的建设和加快三北防护林步伐具有重要意义。杨树育苗,一般来说,插条比较容易。但用插条苗所培育的树木,具有树干容易发生心腐、寿命缩短等不良现象。因此,我们在大面积培育杨树插条苗的同时,培育了杨树实生苗,并取得了较好的效果。二白杨种子来自酒泉,当年9月调查,苗高18厘米,地径0.3厘米,每亩有苗4—7万株。
Populus nigra var thevestina × P.Simonii is a fine natural hybrid selected by our province. Hexi Corridor in the vicinity of a long history of cultivation, is the main afforestation species. It is tall dry, beautiful tree, fast growth, cold and drought, but also more saline-alkali. Germination early, late leaves, longer growing season. Therefore, the rapid development of Populus tomentosa is of great significance to the construction of forest protection forest in all fields and the acceleration of the pace of forest protection in the Three North. Poplar seedlings, in general, cuttings easier. However, the cuttings nurtured by the trees, with heart-trunk prone to heart, shortened life expectancy and other undesirable phenomena. Therefore, we cultivate poplar seedlings at the same time we cultivate the poplar seedlings on a large scale and achieved good results. Poplar seeds from Jiuquan, then survey in September that year, height 18 cm, diameter 0.3 cm, seedlings per acre 4-7 million.