Sooty blotch is a superficial disease of apple and other pome fruits.
It is common throughout the central and eastern apple-growing sections of the United States, but it is rare in the Northwest. The disease occurs in the orchard mainly on late-summer and winter varieties, blemishing the fruits and reducing their market value. Sooty blotch does not develop or spread in transit or in storage and is of minor importance on the market. The spots have irregular shapes and indefinite outlines. They vary greatly in size.