Unless infected fruit is placed in cold storage immediately after harvest, the spots increase in size and become more sunken, thus more visible. The disease cycle is much like that of apple scab, except it begins later in the spring. About the time of petal fall, ascospores are discharged from fallen leaves. Just how the fungus gets on the leaves is not known, as there is no evidence of the disease on leaves while they remain on the trees. Rain and high humidity favor spore discharge and infection of fruit.
Infections continue until midsummer, although they decrease as the season progresses.
Disease management Routine fungicide applications normally control this disease in Pennsylvania. Summer fungicide applications should not be extended beyond 14-day intervals.