Sclerotium rolfsii, is a soil-inhabiting fungus that causes Southern stem rot of peanuts from the mid- to late-part of the growing season. The fungus may become seedborne by infecting developing and/or mature seed in pods at this time. Frequently, infected seed will have skins with bluish-gray or bluish-black patches of discoloration. Evidence of the fungus in seed will become apparent in germination tests, wherein the fungus produces a dense mold growth over the surface of seeds. In most instances, the white mold will rapidly decay germlings and result in disqualification of affected seed for certification.