EEUU: Zebra chip confirmed in four Idaho fields

Olsen said the most recent infected tubers were found during harvest in Twin Falls County on Sept. 25 and in Minidoka County on Sept. 28. The first confirmed infection was reported in Ada county on Aug. 13, followed by a confirmed infection in Power County on Sept. 10.

Olsen said each county’s case involved a couple of tubers, at most, from a single field. Olsen said the tubers were discovered either during test digs or random crop sampling.

Zebra chip, caused by the Liberibacter bacterium, first arrived in the Pacific Northwest in 2011 and is spread by tiny, winged potato psyllids. It’s characterized by patterns throughout tuber flesh that darken during frying. There were no confirmed cases in Idaho tubers last season.

“We have a very small smattering of it,” Olsen said. “I don’t think we have a lot out there. Otherwise, we would have a lot more people talking about it.”

Olsen said the Columbia Basin has also reported a “smattering” of zebra chip infections.

She advises growers to keep an eye out for zebra chip during harvest and while loading potatoes into storage. The disease isn’t known to spread from infected tubers to clean spuds in storage, but symptoms may develop in storage in infected tubers.

“You can possibly see a little bit show up in storage that you didn’t see at harvest, especially if the infection came in late season, but we’re not seeing significant increases in storage,” Olsen said.