Black root rot is caused by a soil-borne fungus. Uneven plant growth in a tobacco field can indicate the presence of this disease. Affected plants are stunted compared to neighboring healthy plants, and plants may turn yellow. (Photo: William Nesmith, UK)

The tell-tale symptoms of black root rot are the black lesions that develop on roots. These black lesions are in sharp contrast to the white color of healthy roots. (Photo: Cheryl Kaiser, UK)

As decay progresses, more and more roots become dark brown to black in color until the entire root system is affected. (Photo: University of Kentucky Plant Disease Diagnostic Lab)