Sooty blotch
Disease
Sooty blotch
Peltaster fruticola (Johnson, Sutton, Hodges) Leptodontium elatius (G. Mangenot) De Hoog Geastrumia polystigmatis Batista & M. L. Farr, and other fungi
Distribution: Sooty blotch and flyspeck occur almost everywhere apples are grown and often occur together; more severe in humid and warmer climates.
Photos
Sooty blotch appears olive green on the fruit surface. Colony shape ranges from nearly circular with distinct margins to large and amorphous with diffuse margins.
Thomas Burr, Cornell Univ.
B
Sooty blotch and flyspeck are found together on the same fruit and affect only the epidermal layer of the fruit (A). Sooty blotch appears as various shades of olive-green on the surface of the fruit. Colonies range in shape from nearly circular colonies with distinct margins to large, amorphous colonies with diffuse margins (B). The variation in colony appearance can be attributed to the interaction among the different fungi causing the disease and environmental conditions, specifically temperature and relative humidity.