Scurf of Sweet Potatoes
Dan Egel, Vegetable Disease Specialist, Purdue University
Gardeners may occasionally observe sweet potatoes with discolored areas such as seen here. These symptoms are of the disease known as scurf of sweet potatoes. Although the discoloration is superficial and seldom affects the interior of the tuber, infection allows excess moisture loss. Thus, affected tubers may shrivel and crack resulting in decay of tubers.
The fungus that causes scurf overwinters on diseased tubers and related plant debris. The use of healthy tubers or sprouts grown from healthy tubers is the most important control measure. Crop rotations of 2 to 3 years in light soil and 3 to 4 years in heavy soil will help to reduce the inoculum of the soil scurf pathogen.