Cherry leaves atypical spot disease
Dear expert, On their website I read the description of cherry leaf spot disease, the disease caused by pathogens of Brumeriella jaapii. This pathogen develops whitish acervulus on the leaves back side and the spots are 1-2 mm small. This year, on the leaves of cherrytrees 2-4mm round (spherical) brown spots developed, conidia neither back nor other surface. Leaves fell. The symptoms were similar to your picture, but this is not typical symptoms. Can you tell me, which fungi cause this spot disease? Thanks
Outside United States
Diagnosing fungal diseases is quite complicated and rarely is it possible from leave forms alone. Even the cherry spot you suggest has effects on fruit and stems. For a diagnosis one needs to evaluate more fully the tree including bark, stems, fruit etc., as well as growing conditions and context. Additional images of the tree may help here, but if you need a definitive diagnosis you should contact a local agricultural office near where you live and have someone do a visual inspection.
The leaf spots would suggest some sort of fungal infection, so you can begin by doing the usual treatments... ensuring all leaf- and fruit-fall are removed and put in the garbage or buried deeply away from the orchard, practicing annual pruning to ensure good air circulation, using regular dormant spray, etc.