用截头法栽植杨树防治溃疡病机理的研究

由Dothiorella gregaria Sacc.引起的杨树大斑型溃疡病在辽宁、河北和山西等省为害严重,它是影响造林成活率的主要因素之一。国内外许多学者一致肯定树皮含水量的增加能提高对皮部溃疡病的抗性。钟兆康曾认为,由Dothichiza populea Sacc.etBr.所致的杨树溃疡病的发生还与树干失水有关。我们的试验表明,由D.gregaria引起的大斑型溃疡病受木质部相对含水量的影响最大。因此使用截头法栽植杨树,对防治溃疡病、提高幼树成活率和生长量均有显著作用。这一结论已为大面积推广应用所证实。本文着重对这种栽植技术的防病机理是否与提高了树体含水量有关作进一步探讨。

A STUDY ON MECHANISM OF CONTROLLING CANKER DISEASE BY USING CUT TOP METHOD FOR PLANTING POPLAR TREES

When planting trees, all of branches and tip of trunk from 1/3 of top ofone year-old part were cut off. As a result of surface reducing of trunk,bran-ches and leaves, the water-consumption in the treatment was less than inthe contrast. Furthermore, the number and total length of roots were increa-sed. So that the relative water content in the treatment was higher than inthe contrast. The results reveal that the poplar trees canker disease caused byDothiorella gregaria was reduced with relative water content increased. Theeffect of controlling is about 60%.