dark brown spots on sweet potatoes

Scurf on sweet potatoes. Charles Averre, North Carolina State University, Bugwood.org

Updated: April 21, 2021

Dark spots on sweet potatoes

Sweet potatoes that develop dark spots may be infected with a fungal disease that may cover the entire skin surface. The injury is superficial, however, and does not affect eating quality. Prevent the problem by buying disease-free slips for planting. Scurf can persist for several years in garden soils that receive yearly manure applications.