Its uses include control of downy mildews, rusts, and redfire disease. It is used to control almost all fungal diseases of plants except powdery mildews. In agriculture, downy mildews are a particular problem for potato, grape, tobacco and cucurbits farmers. Ampelomyces quisqualis is an anamorphic fungus that is a hyperparasite of powdery mildews. Powdery mildews are generally host-specific. In most powdery mildews only the epidermal cells are attacked. The signs of powdery mildews are widely recognizable and easily identifiable. Most of them are called downy mildews. It is tolerant to chalybeate (iron-enriched) water, but may succumb to powdery mildews. Chasmothecium are signature of all powdery mildews and can be identified by their appendages. Paper is a kind of material which mildews and rots easily. "Ampelomyces quisqualis" is an anamorphic fungus that is a hyperparasite of powdery mildews. "Peronospora" has far more species than any other genus of the downy mildews. It closely follows the standard life cycle of powdery mildews. Both of these mildews are obligate biotrophs, meaning that they can only infect living tissue.