In reference to wine, "peronospera" is a fungal disease that has the ability to cause severe damage to the vine. The mildew attacks multiple parts of the vine, including the flowers and the fruit. The leaves of the vine are covered with a white growth. This type of fungi is found in wet, humid areas. Also known as "downy mildew". Growers control mildew by applying copper sulfate sprays or various forms of sulfur.