河南省新发杨树黄叶病害的发生特性研究

Studies on Yellow-leaf Disease of Populus in Henan Province

对河南省2005年以来新发生杨树黄叶病害的发生特性进行了研究。结果表明,2008年病害危害继续扩大,新发病地块出现50处,但老的发生区没有大面积扩散,枯死数量所占前年总病树的百分比从2007年的1%下降到了0.6%。黄叶病杨树存在侧芽萌发及顶芽小叶现象,但不属于植物病理学上的丛枝。病害在春秋两季发病明显,实验证明病害与越冬关系不大,7月份有隐症现象,该隐症为高温隐症。加强水肥管理及间伐对缓解症状有一定作用,但是不能彻底治愈,病因可能与苗木的来源有一定关系。病害的发生在立地条件上没有明显规律,养殖小区和菜地内的杨树明显发病较早、较重。未发现明显抗病的杨树品种,法桐等其它近10种树种亦有类似症状。

The imperlment of populus yellow-leaf disease in Henan province extended sequentially,including 50 new regions,but in the old regions the disease didn＇t diffused extensively.Relative to2007,the percentage of died populus is decreasing from 1% to 0.6%.The sprouts bourgeoned abnormality in part of the ill populus and its topmost leaves were morbidly small.However they were different from the pathologic witche＇s broom in the autumn and spring,this disease diffused evidently.This disease has no necessary connection with populus liveing through the winter.It Masked Symptom Under High Temperature Stress.Preferable management was usable on lightening the state of illness,but it couldn＇t be cured completely.There was no rules on planting situation.The states of illness were worse and earlier.By investigation,The pathogeny may be relatived to the populus origin.No Disease-Resistant populus breeds were discovered.In the other tree species（e.g.platanus orientalis）the similar yellow-leaf disease were existent.