clusters and leaves of white grapes, affected by powdery mildew or oidium, with berries and branches covered with a white powdery

agriculture branch bunch closeup disease diseased downy fertilizer food freshness fruit fungal fungicide fungus garden grape grapevine green growing harvest hazardous healthy infection leaf like mildew mold mushroom natural nature oidium organic outdoor pathogen plant powdery rotten sick spore spot spray spread summer uncinula vine vineyard viticulture white wine