Rhizoctonia violacea is a pathogenic fungus that causes serious diseases in various plants, including beets. This fungus is characterized by the formation of resistance structures called sclerotia, which are compact masses of purple or violet mycelium, capable of surviving in the soil for several years in the absence of a host. When environmental conditions are favorable, especially moist soils and moderate temperatures, sclerotia germinate and produce infectious hyphae. These hyphae grow and penetrate the roots and the base of the stem of the plants, causing necrosis and deterioration of the plant tissue. As the fungus develops, a visible cottony mycelium forms around the infected areas, making it easier to identify.