树木的溃疡病

树木溃疡病是指枝干皮层局部坏死的病害,在针阔叶树上常有发生,为害严重的常环切枝干,引起树木死亡。侵染性树木溃疡病主要由兼性寄生真菌侵染所致,也有个别是由细菌引起的。本文根据作者多年的观察和部分文献对树木溃疡病的症状、病原、侵入途径、侵染时期、侵染发生的条件,寄主的抗病性和防治方法作了一般性的讨论。树木通常只有在栽培不当或受不良环境条件的影响而致生长削弱时,才会发病。病害防治首重分析发病的诱因,采取合理的造林技术措施,消除各种削弱树木活力的因素。在有条件的地方可以考虑化学防治。

The Tree Cankers

Tree cankers are defined as localized rigions of necrosis in the bark of stems or branchs. The infectious diseases are mainly caused by facultative fungi, occassionally by bacteria, and usually found in conifers and hard woods. Damages from small depressions in the outer bark to a rapid girdding of the branchs and stems with high mortality occur consequently. On the basis of authors’ recent investigations the symtoms, pathogens, paths and seasons of infection, host resistance, environmental conditions affecting disease development and control of the tree cankers were generally discussed. The symptom of the tree cankers developed usually in the early spring when host plants were weakened by adverse enviromantal factors such as drought, frost, unfavorable soil conditions, mismanagement,insect damage etc. Intensively silviculture managements can promote the growth vigor of trees that is commonly known as an economic and effective measure to prevent the infection of tree cankers. In the cases of trees infected with various initial lesions, treatments with fungicides are advisable.