girasol plants affected by powdery mildew

girasol plants affected powdery mildew sunflower tuberiferous earth pear longterm grassy plant cultural flora fodder technical food family struck infected disease mealy dew bel fungal muchnistorosyany mushrooms parasite white raid nature ecology ecological problem crop production agriculture summer helianthus tuberosus asteraceae erysiphales perisporiales erysiphe cichoracearum dc helianthi jacz