梨干枯病的发生与防治梨干枯病主要发生在１－２年生幼龄梨树的主干上，个别出现在４－５年生树上的１－２年生枝条基部。此病１９８８年在本地区普遍发生，在基地调查表明，病株率达１６．９％。现将其在延边苹果梨树上的发生情况与防治方法介绍如下。一、病原及症状梨干... Pear Blight Occurrence and Control Pear blight mainly occurs on the trunk of young perennial 1-2 year old perennial trees, and individual perennial 1-2 year old branches occur on the 4-5 year old tree. The disease occurred in 1988 in the region generally, the base survey showed that the diseased rate of 16.9%. Now its occurrence in Yanbian apple pear tree and prevention methods are as follows. First, the pathogen and symptoms of pear dry ...