University of Forestry, Dep. of Plant Pathology and Protection, BG - 1756 Sofia, Bulgaria
RADILOVA, I, 2004. Identification of races of rose powdery mildew pathogen Sphaerotheca pannosa var. rosae in Bulgaria. Bulg. J. Agric. Sci., 10: 323-327
Twelve monoconidial isolates of Sphaerotheca pannosa var. rosae (Wallr.) Lev., the pathogen that causes powdery mildew of roses, was obtained from infections on twelve rose cultivars from six locations in Bulgaria. Isolates were initiated on detached leaves, increased on host plants, and inoculated to six rose cultivars to test for differential reactions. Virulence was evaluated by assessing the infection type of individual lesions. Four races of Sph. pannosa var. rosae were identified, and virulence formulae were developed to describe them on five differential rose cultivars.