掌握杨梅根腐病早期症状是取得既经济又有效的防治效果的基础。在调查该病害发生情况的基础上 ,采用断根和接致病菌等方法模拟其早期症状。发现单株早期症状主要是 :盲芽增多 ,叶色变淡 ,非正常落叶增加 ,部分枯梢 ,老干上抽生细小新梢复又枯死。根系的早期症状表现为部分细根和根瘤先枯死 ;多数树体的坡下侧根系先发病枯死。在诊断中还要区分枝叶病虫害和生理病害引起的症状。在群体 (成片 )发病的早期诊断中 ,宜把成片的杨梅林看作是一棵“大杨梅树”。单株发病死亡 ,就是群体早期症状的开始。表 2参 1 To grasp the early symptoms of Myrica rubra root rot is to achieve both economic and effective basis for the prevention and treatment. On the basis of investigating the occurrence of the disease, the methods of root-breaking and pathogenic bacteria were used to simulate the early symptoms. Found that early symptoms of individual plants are: increased blind, leaf color fades, non-normal deciduous increase, some of the shoots, dried up on the small fresh shoot complex and dead. Early symptoms of the root system showed partial fine roots and nodules to die first; most of the tree understory roots first died. In the diagnosis but also to distinguish between leaf disease and pests and diseases caused by physiological symptoms. In the group (into pieces) the incidence of early diagnosis, it should be as a piece of Yang Meilin as a “big bayberry tree.” The death of a single plant is the beginning of a group of early symptoms. Table 2 Reference 1