I noticed this in the potato bed the other day. I've been trying, since then, to figure out what it is. Is this Late Blight? I'm not sure. The way I would describe this is different from the descriptions I've read. I'm growing three varieties. This showed up in the red variety (Red Norland? I forget...) first, but now I see one of the German Butterball plants is affected as well. The potatoes have grown robustly all season and are currently up to my waist and flowering. If this is something that will destroy the crop I may cry. But the sooner I know, the bestter. So I'm hoping that someone more experienced/knowledgeable than I can give me a yea or nay on this. What say you?