Fruitful Land

Sooty Blotch (Gloeodes pomigena) and Fly Speck (Schizothyrium pomi) are a group of similar fungi that cause discoloration on Apples during late summer. The disease severity is associated with wetter summers and/or several cool foggy mornings. The disease only effects the color of the Apple skin and can be removed by washing with a mild bleach solution. The internal quality of the fruit is not affected. These diseases can appear in early summer, but sprays to control Apple Scab usually also control Sooty Blotch and Fly Speck.

Sooty Blotch appears as a green to black smudgey discoloration on the fruit. Fly speck appears as clusters of black dots on the fruit. They usually appear at the same time and they are controlled by the same treatments. It may take several weeks for symptoms to appear.

CONTROL: Growth of these fungi requires extended wetting periods so regular pruning that keeps trees open allowing them to dry quickly helps to limit the degree of infections. Regular mowing of the grass and thinning of adjacent hedges and woods that slow natural air drying is also helpful. If possible avoid planting your trees on fog pockets and poorly drained locations.

Sooty Blotch and Fly speck can also be controlled through fungicides but the exact timing for control may vary from year to year.

Find more detailed information at the following sites and pages:

SOOTY BLOTCH and FLY SPECK from Cornell University

Discuss: Ask you questions, give us your solutions, send us your pictures on our forum.