What you see: Peaches with black spots.
What it is: Peach scab, a disease that tends to stay on the surface.
Eat or toss: Peel. If the flesh below looks fine, eat!
Peaches with black spots like these are safe to eat – just peel first
Known as peach freckles, peach scab, or, in more formal circles, cladosporium carpophilum, the little black dots on this peach are the signature of a certain kind of fungal disease. It’s certainly not appetizing, but don’t toss that peach just yet.
Peach scab’s saving grace is that it tends to stay on the surface. So, if you peel off the skin, the rest is probably fine.
Inspect a scabby peach before eating it
While the little black dots themselves don’t pose an immediate risk, infected peaches are more likely to crack open. That’s because the “scabs” don’t expand as the peach grows, creating a tension that can bust open the skin. Cracks in the skin create inviting entry ramps for microbes that could rot the peach. A fruit infection called “brown rot” often follows a serious case of peach scab.
Wet conditions make scab more likely
Spores of the fungus that causes peach scab tend to overwinter on twigs in peach trees. When it rains, the spores hitch rides on water droplets, which deliver them to the fruit. The spots are usually most dense around the stem because that’s where water from those spore-spreading splashes tends to accumulate.
The “scabs” start out as small, round, greenish spots. They eventually enlarge and darken to an olive green or black, as you see in the images above. While the flesh below the scabbing is usually fine, the Ohio State University Extension reports that scabby peaches don’t store well. Eat spotted peaches first!
Given the fungus’s spread via damp conditions, orchard managers try to keep trees pruned and locate them in sunny, open areas where they’ll dry quickly. Peaches grown in home orchards, which may not be designed for good air circulation and where fungicides aren’t sprayed, are more likely to develop peach scab.
While peaches are especially susceptible to scab, its fellow stone fruit, like nectarines, apricots and plums, can also develop the disease.
Beauty is in the eye of the peach holder
Phillip M. Brannen, a University of Georgia professor and plant pathologist, said grocery stores usually reject very scabby peaches.
But, he wrote in an email, the disorder is so common that the USDA allows up to five scab spots before downgrading a peach. Indeed, in my deliveries from Imperfect Foods, I’ve gotten some scab-sprinkled peaches, likely because retailers with stricter aesthetic standards rejected them.
Brannen said that scab has long been a common affliction of peaches.
“In fact,” he said, “USDA paintings of the perfect peach from over a hundred years ago had some scab.”
- Phillip M. Brannen. Professor and Fruit Extension Plant Pathologist. Plant Pathology Department. University of Georgia
- Scab of Peach, Nectarine, Plum and Apricot. University of Illinois Extension. College of Agricultural, Consumer and Environmental Sciences. September 1998.
- Peach Scab. Daniel Mancero-Castillo, Ali Sarkhosh, Mercy Olmstead, Phillip Harmon. University of Florida Institute of Food and Agricultural Sciences.
- Disease Profile: Peach Scab on Stone Fruit. Cornell University. College of Agricultural and Life Sciences. New York State Agricultural Experiment Station.
- Peach Scab. Kevin Ong, associate professor and extension plant pathologist; Corinne Rhodes, extension assistant. Texas A&M Agrilife Extension.
- Peach Disease – Scab. Kari A. Peter. PennState Extension. Updated: Oct. 18, 2017.
- Scab of Peace, Nectarine, Plum and Apricot. Michael A. Ellis, Department of Plant Pathology. Ohioline. Ohio State University Extension. Originally published 2008.
- Peach Scab. Ontario Tender Fruit IPM. Ministry of Agriculture, Food and Rural Affairs.
Images in this post are courtesy of Phillip M. Brannen of the University of Georgia.
If you’re thinking, “Same old scab story,” you’re right! We previously wrote about a similar affliction that strikes apples.