I have had leaf blight on my tomatoes and potatoes for several years, and I plan on moving my garden because of it. I have saved seed potatoes from the infected garden. Would I be transferring a problem being the seed potatoes were grown from the infected garden. I believe the blight is the early leaf blight where the tomato leaves turn yellow and fall off.
Stearns County Minnesota
Potato tubers usually become infected with the fungus when immature or wounded tubers are lifted from the ground through soil infested with fungal spores. Since you are planting potatoes in a fresh location and since you have no way of knowing if your seed potatoes are infected, I would recommend that you not use them. You may as well make a fresh start on new soil and seed.
Several foliar fungicides are registered for early blight. Mancozeb, chlorothalonil and copper are effective against early blight when applied at approximately 7-10 days intervals. Spraying should commence at the first sign of disease or immediately after bloom.
To read more about early blight on potatoes: http://www.extension.umn.edu/garden/yard-garden/vegetables/early-blight-of-tomatoes-and-potatoes/