for the first time ever, I had a problem with potatoes last year. I grow about 4 varieties, and I've been replanting from potatoes saved from seed for 3 years in this garden. I grow fingerlings, russet, yukon gold, kanabec, and a variety of purple, plus whatever sprouting potatoes family give me. Last year, I had small black or darkened centers in about 1/4 of the potatoes, mostly in the whites. Not worms, as there was no worm trail. The reds had red stippling in the center. It was an extraordinarily dry and cool summer. I rotate crops, and grow some potatoes under hay, and some under dirt. I have a big family harvest day, so have no idea of whether the problem potatoes came from one patch or another as I also had kids up helping to plant last spring and totally lost track of what was what. Any ideas what this was about? would like to avoid it this year!