Sweet potatoes looking spotty?

This sweet potato has scurf, a fungus that can be peeled off because it only affects the skin.

What you see: Dark patches on the skin of your sweet potato What it is: Scurf, a sweet potato fungus Eat or toss? Peel and eat! This fungus only grows on the surface of the potato, so once you’ve peeled it, you’ve eliminated the problem

The story:

Sweet potatoes looking a bit spotty? They may have something called “scurf.” This fungus manifests as dark brown to grayish patches on the skin of the sweet potato. It can look rather shadowy and foreboding, but there’s nothing to fear here. Simply peel the potato and, as long as everything looks normal beneath the skin, you’ve peeled off the problem.

But, once you spot some scurf, try to use up the sweet potatoes quickly. There are a couple of reasons for this, according to Brandon Parker, an agriculture agent with North Carolina State University's cooperative extension program. First, scurf-infected sweet potatoes could pass their condition along to other sweet potatoes. Second, even though scurf is only skin deep, if the sweet potatoes are stored for an extended period of time, say, several months, they could be more susceptible to other, less approachable invaders. Such decay organisms could cause rots that will make the potatoes unusable.