据调查,冈山县因病毒而引起的果树病害,达果园总面积的35%。目前,在国际上已被确认的果树病毒病有30多种,在日本发生较多,分布较广的主要有卷叶病、扇叶病、斑点病、栓皮病4种.卷叶病的症状是在采前叶变为红色,只在叶脉的周围残留有绿色,叶的外缘卷曲。果实表现过度的成熟,含糖量低;扇叶病的主要症状是叶发生畸形;斑点病在一般 According to the survey, Okayama Prefecture due to the virus caused by fruit trees, up to 35% of the total area of ​​orchards. At present, there are more than 30 kinds of fruit tree virus diseases in the world, more than 30 kinds of fruit tree virus diseases occurring in Japan and widely distributed mainly including leaf roll disease, leaf disease, spot disease and cork skin disease. The leaves are red before the harvest, leaving only the green around the veins, the outer edge of the leaf curl. Fruit over-ripe, low sugar content; leaf blade is the main symptom? My leaf deformity; spot disease in general