苹果落花后到套袋前,需要防治的主要病害有:苹果斑点落叶病、轮纹烂果病、苹果炭疽病三种。一、发病规律 1.斑点落叶病 苹果斑点落叶病主要为害春梢期的幼嫩叶片,形成病斑,严重时造成落叶。另外,斑点落叶病还可侵染幼果,在果面上形成小红点,导致果面不洁净,降低套袋果等级。 2.轮纹烂果病 Apple bagging before falling after the need to prevent the main diseases are: apple spot deciduous disease, rotten rotten wheel pattern, apple anthracnose three. First, the incidence of law 1 spotted leaves Apple spotted leaves of the main damage to young shoots of young leaves, the formation of lesions, causing severe deciduous leaves. In addition, spotted leaf deciduous disease can also invade young fruit, forming a small red dot on the fruit surface, resulting in the fruit surface is not clean, reduce the bagged fruit grade. 2 rotten rot rot pattern