Sweet potatoes are susceptible to a variety of field and storage diseases. The most common diseases affecting sweet potato production in Alabama and the management practices required for their control are described in this publication. Black Rot Black rot is caused by the fungus Ceratocystis fimbriata. The disease can cause significant losses in storage, in the transplant bed, and in the field. The pathogen not only reduces yield and quality but also gives sweet potatoes a bitter taste.
Spots enlarge and appear greenish black to black when wet and grayish black when dry.
The rot usually remains firm and shallow. Tissue near the discolored area may have a bitter taste. Eventually, the entire root may rot. Roots may appear healthy at harvest but rot in storage, during transit, or in the market. Internal and external views of roots infected with black rot.