Direct infection is primarily of the leaves and can lead to defoliation.
Defoliation, in turn, leads to a reduction in yield and may cause fruit to ripen prematurely. Fruit may also be damaged due to exposure to the sun and wind. Environmental Conditions Infection by A . Especially important are the periods of leaf wetness which allow spores time to germinate and penetrate the leaf cuticle. F are optimal along with 18 hours of high relative humidity.