With Thanksgiving on the way, we decided to highlight a common disease of sweetpotatoes, but don’t worry, it wont affect the taste of your sweetpotato casserole! Scurf is caused by the fungus Monilochaetes infuscans. The fungus only grows in the sweetpotato skin and produces spores on the surface of the skin. As shown in the photos, the dark splotches on the skin are areas infected with the fungus. The fungus does not penetrate below the skin, so the sweetpotatoes are still edible, but because of the dark discoloration that results, diseased sweetpotatoes have lower market values.
Healthy sweetpotatoes are infected by spores present in the soil. The disease can also spread through contaminated crates, baskets, and storage houses. The fungus does not attack the above-ground portion of sweetpotato plants, and does not attack other hosts so rotation is an effective way to prevent scurf problems. Scurf is usually worse during rainy seasons.
For more information and control recommendations, click here