Cotton (Gossypium barbadense L.) is one of the strategic farm crops, which is widely cultivated and traded across the world and one of the most important export crops of Egypt. Cotton seedling diseases are a worldwide problem; they are caused by a complex of soil-borne organisms. These organisms are found in all cotton-producing areas in Egypt, including Rhizoctonia solani and Fusarium spp. (Asran-Amal et al., 2005). R. solani Kühn. the anamorphic of Thanatephorus cucumeris (Frank.) Donk, causes seedling blight, pre-or postemergence damping-off, sore shin and root rot of cotton seedlings. R. solani colonizes soft tissues and forms infection cushions. From these cushions, the fungus penetrates the epidermis and destroys plant cells (Watkins, 1981).