油橄榄干腐病的症状是树干和枝的韧皮部发生局部绛褐色坏死,开始发病时树皮产生小肿胞凸起,继而产生树皮的坏死开裂(见照片一、二),用刀将肿胞削开观察,韧皮部组织已经破坏,肿胞内变为绛褐色颗粒状物。这种局部坏死的症状会逐步蔓延扩大成块状,至整个树干或枝的韧皮部形成环状或大部分坏死时,就会造成一个树枝或整个植株的死亡。对于这种病症,我省引种以来一直未弄清病因。据原国家林业总局1977年编的《油橄榄栽培》第144页称:此病害究竟 The symptoms of dry rot of the olive tree are the local brown-brown necrosis of the phloem of the trunk and branches, the emergence of a small swelling of the bark at the onset of the disease and the consequent necrotic dehiscence of the bark (see photos I and II) Open observation, the phloem tissue has been destroyed, the cytoplasm into brown particles. The symptoms of this localized necrosis will gradually spread and expand into lumps, which will cause the death of one branch or whole plant when the phloem of the entire trunk or branch forms a ring or is mostly necrotic. For this disease, the province has been introduced since the etiology. According to the original State Forestry Administration in 1977, edited “olive cultivation” page 144, said: This disease exactly