Sooty blotch and flyspeck is considered a complex of several fungi that usually occur on the same fruit. Sooty blotch appears as superficial, dull black spots or blotches that may merge to cover most of an apple. Flyspeck appears as clusters of 6 to 50 or more slightly raised, black, shiny, round dots that resemble fly excreta (frass). Environmental conditions that favor disease development are moderate temperatures and extended wet periods in late summer/early fall.
Sooty blotch and flyspeck live on the surface of the fruit. Damage is mainly cosmetic. (The black discoloration can be removed by vigorous rubbing.) The skins on the apples can be eaten, they just don't look very appetizing.
Management
Several cultural practices aid in the control of sooty blotch and flyspeck. Pruning, which facilitates drying, has been shown to reduce disease incidence and severity. The value of pruning, however, is somewhat dependent on the season. It appears to help more in dry seasons than wet seasons. Proper thinning of fruit is also helpful. These tactics, combined with the use of protectant fungicide sprays, can help reduce the cosmetic damage on the fruit.
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