Coccomycosis of Stone-Fruit Crops

a disease of amygdalaceous fruit trees, caused by the Ascomycete Coccomyces hiemalis (conidial stage, Cylindrosporium hiemale). It primarily affects the leaves; small reddish spots appear which subsequently enlarge and merge. In damp weather a pinkish film develops on the underside of the spots. A severe affection causes the leaves to turn brown and dry; the dead tissue often falls out, forming little holes. Coccomycosis of stone-fruit crops is widespread in the USA and Western Europe; it is found in the USSR in Latvia, Estonia, Byelorussia, Kaliningrad Oblast, and the Ukraine. Favorable factors for the disease are a rainy summer, abundant dew, severe fog, and temperatures around 21°C. Control measures call for removing and destroying fallen leaves and treating the plants with fungicides.