Leaf spot of roses.
In early summer, especially the cool and rainy, on the leaves of roses may appear brown spots, which gradually merge and blacken. Black spots appear on the swelling round or oblong. The causative agent of black spot fungus is Marssonina rosae.
The affected leaves turn yellow and fall off roses, shrubs laid bare - immunity decreases roses, plants wilt and in the future do not grow and bloom. In addition to black leaf spots on the leaves of roses may be brown spotting (brown spots with a black border) and white spotting (white spots with dark red rim) - these diseases provokes high temperature and humidity.
Rinse the affected spots, fallen leaves roses to collect and burn, and then take the same measure that against powdery mildew. Against the blights on the leaves of roses are also Benlatom, Zineb. Mulching the soil in the rose garden sloped crushed grass stops the spotting the leaves of roses. Rose with glossy leaves are less susceptible to spotting.