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河北杨,陕北又叫青杨、串杨、白杨树。其耐寒、耐旱、耐瘠薄、适应性和萌蘖力强,是干旱荒山造林的优良树种之一。在我区延安以北各县分布较多,多为散生或零星小片,也是群众喜爱的乡土树种之一。过去,河北杨利用根蘖进行繁殖,发展速度较慢,用插条繁殖,由于未掌握其规律,成活率不高,因而影响了河北杨的发展。为了大力发展河北杨,给大面积荒山造林提供苗木,我们从1977—1979年在延安市河庄坪苗圃,连续3年进行了河北杨扦插育苗试验,取得了较好的效果。1978年塑料薄
Hebei Yang, northern Shaanxi, also known as green, string Yang, poplar. Its cold, drought, barren, adaptability and strong sprouting, is one of the fine tree species afforested in arid barren hills. In our district, there are more counties in north of Yan’an, mostly scattered or sporadic patches, and also one of the native tree species favored by the masses. In the past, Hebei Yang breeding with root tillers, the development of slower, with cuttings propagation, because they did not grasp the law, the survival rate is not high, thus affecting the development of Hebei Yang. In order to vigorously develop Hebei Yang, large areas of barren hills afforestation to provide seedlings, we from 1977 to 1979 in Yanzhuang Hezhuangping nursery, Hebei poplar cuttings for 3 consecutive years, and achieved good results. Plastic thin 1978