研究证明,苹果果实轮纹病最初侵染菌源来自于枝干上的轮纹病斑。但对枝干上轮纹病的侵染及发病时期和孢子释放期等仍不清楚。因此针对这方面的问题继续作了调查和试验。一、枝干上病症及活动情况 Studies have shown that the initial source of apple fruit ring rot infection from the rotten lesions on the branches. However, it is unclear on the infection of rotundrides on the stems, the period of onset and the period of spore release. Therefore, investigations and experiments on this issue continue to be conducted. First, the symptoms and activities of the branches