My folks taught me this. Old timers knew this stuff. And you can research this. Nowadays, they have potatoes that are resistant, maybe? Why take a chance. Just do it right the first time.
Ever hear of potato scab?
Potato scab is an undetectable disease that most gardeners discover at harvest time. Depending on the extent of the damage, these potatoes may still be edible once the scab is removed, but they’re definitely not fit for the farmer’s market. Read on to learn more about potato scab disease and how to prevent it next season. What is Potato Scab? Once you’ve unearthed scabby potatoes, you may ask yourself, “What causes potato scab?” Unfortunately, the source of infection isn’t a rare, short-lived pathogen; it’s a soil bacteria that can remain in the ground indefinitely as long as decaying plant matter is left behind. The bacteria, Streptomyces scabies, thrives in soils with a pH above 5.5 and temperatures between 50 to 88 F. (10-31 C.). The growing conditions needed by potatoes are very close to the conditions that scab prefers. Potato tubers suffering from scab are covered in circular lesions that may appear dark and corky. When many lesions are present, they sometimes grow into one another, creating irregular patches of damage. Surface scabs are annoying, but are usually able to be cut away and part of the potato salvaged. More serious disease can develop, causing deep pitting and cracking that allows secondary pests and diseases to make their way into the tuber’s flesh. Treating Scab in Potatoes SKIP AD Potato scab control is targeted at preventing infection in potatoes; once your potatoes are covered in scab, it’s too late to treat. Future potato beds can be protected from scab by keeping the soil pH of beds around 5.2 with liberal applications of sulphur. Avoid the use of fresh manure where scab has been a problem; well-composted manure is generally free of pathogens due to the heat involved in the process. Always amend potato beds in the fall if scab is a perennial problem.
Read more at Gardening Know How: What Is Potato Scab Disease: Tips On Treating Scab In Potatoes
https://www.gardeningknowhow.com/edible/vegetables/potato/treating-scab-in-potatoes.htm