Botrytis bunch rot and blight of leaves, shoots and blossom clusters, also called gray mold, occurs throughout the viticultural world. The fungus causing the disease grows and reproduces on senescent or dead plant tissue. As a disease-causing organism, it is responsible for crop loss in a wide variety of unrelated crops. Botrytis bunch rot is especially severe in grape cultivars with tight, closely packed clusters of fruit. Botrytis is also responsible for storage losses of grapes picked for fresh market. In addition to its crop loss potential, Botrytis infection of ripe fruit of certain cultivars, combined with precise climatic conditions, results in a condition called “noble rot” and is the prized ingredient in the Auslese, Beerenauslese, and Trockenbeerenauslese wines of Germany, the Sauternes wines of France, and the Tokay wines of Hungary.