Description:A fungal disease that causes circular, black spots on leaves up to 12 mm diameter. The edges of the spots are irregular or fringed. Leaves turn yellow and fall as the disease progresses. Plants continually infected are weakened, have fewer and smaller flowers and may show die back of branches or succumb to other diseases. On very susceptible varieties young stems may also be affected.
Biology:Favoured by humid weather with temperatures between 13 and 240C.
Life Cycle:Origin and History:
Related and Similar Species:References: