意大利杨树繁殖培育

匈牙利的林业专家研究出一种用集装箱密集繁殖白杨树的方法，良种白杨树可以用无性繁殖的方法培育根系。放入集装箱的压条周围堆上泥炭和珠光石，集装箱周围开一些孔，从孔里可以看见压条。这种集装箱苗圃具有与温室一样的条件，营养期结束后，从箱里取出压条。采用这种方法一根压条能长100～150条树根，而传统方法只能长10～15条树根。

Based on the results of more than ten year's scientific research and practice, some key techniques for cultivating poplar veneer glued wood were summarized systematically. The results were as follows: (1)Selecting appropriate poplar clones for various cultivation zones according to their growth rate and wood quality. (2)Choosing good sites being suitable for poplar clone growing (at least SI≥18?m). (3)Adopting reasonable planting density which can produce more timbers to meet the need of plywood(the tree spacing should be more than 5?m×5?m). (4)Using correct planting methods for different soil conditions, however, large seedling with 2 year old root and 1 year old stem (seedling height>4?m)were advocated. (5)Taking effective measures to tend the stand, the most effective measure was interplanting with crops. (6)Pruning was neccessary to produce non node timber, but pruning method, pruning intensity and pruning season should be controlled properly. If the 6 measures mentioned above were carried out, the poplar forests with a high yield and high quality could be ensured. In order to provied some theoretical basis for cultivating poplar veneer glued wood, 4 optimum cultivation patterns were also established using the method of two dimensions system.