IDAHO FALLS, Idaho (AP) — The University of Idaho is reviving a group to fight a cyclical bacterial invasion that's attacked the state's potato fields with a ferocity not seen in a decade. First the good news: Bacterial ring rot isn't a public health risk. But its potential to taint the appearance of Idaho's signature agricultural crop with an unappetizing, cheese-like decay of the ring surrounding a tuber's circulatory system makes it a feared arrival in any farmer's field. University of Idaho Extension seed potato specialist Phillip Nolte in Idaho Falls says growers contained outbreaks in 2002 and the 1990s by stepping up sanitation practices. He's looking for similar measures to control current infection rates that are heavy in some fields. The outbreak's full extent won't be known until this year's harvest later this fall.