Plant Diseases

Bot Rot

White Rot

Bot Rot
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Bonide Solutions:
Bot rot is an important disease of apples but also impacts pears, crabapples, quince, chestnuts and grapes. The disease can produce distinct cankers on trunks and branches as well as two different types of fruit rot. Leaf infections do not take place with bot rot. An increase in infection of Bot Rot can be due to winter injury and drought stress.
Cankers can be seen in early summer as small circular spots or blisters. The blister as it grows becomes somewhat sunken in appearance. By late fall the cankers stop enlarging. Then in spring, small black structures containing spores form on the cankers. The outer bark of older cankers can be orange and papery with the tissue beneath being slimy brown.
Fruit rot can occur in two different ways, externally as lesions as the fruit is developing and internally during storage. The external rot is sunken, egg shaped and brown with often a red halo.
Applications of fungicides must be done in conjunction with sanitation. Good sanitation reduces inoculum levels in the orchard. Carefully prune out dead wood, cankers and other infected wood such as from fire blight in apples. Properly dispose of prunings and all mummified fruit by burial or burning.