A disease in potatoes originally found in New Mexico has traveled to Idaho. The disease — “Zebra Chip” — has no known threat to humans, but this disease is an issue for the potato industry.
Zebra Chip begins with a bacteria carried by psyllids (tiny insects related to aphids).
“Essentially what’s happening here is that it can cause a very mild marking inside the flesh of the potato. So if you cut open a raw potato you might just see a slight little discoloration,” said Nora Olsen, an associate extension professor at the Idaho Center for Potato Research and Education. “You can still eat it — there are no human or health concerns at all.”
Some of the samples have gone unnoticed through the system, but scientists were not too surprised to see this disease in Idaho, Olsen said.
“We were on the watch for it in Idaho. So the system did work — we found it very early and so now we can get information out to everybody and education on what to look for and what we need to do differently next year possibly to not have some infection by these potato psyllids,” Olsen said.
Bill Loftus, science writer in the College of Agricultural and Life sciences, said this may be the only year Zebra Chip occurs in Idaho, but it’s still important for potato growers and processers to be aware that the disease is out there.
“Our researchers like Nora Olsen and Phil Nolte are some of the best in the business. Phil Nolte down in Idaho Falls wrote about this two years ago because he was already tracking it in Texas and Nebraska and Kansas and California,” Loftus said. “You know, they grow a lot of potatoes there too but they’re not as important as potatoes are to Idaho.”
Loftus said it’s important to find a balance when communicating information about a somewhat threatening disease. It’s important to relay the message to the potato industry without exaggerating it, he said.
“The Idaho Potato Commission wanted to make sure growers knew about it. They also wanted consumers to understand that it’s not a human health threat,” he said. “It’s basically a cosmetic issue because the sugar balance in these potatoes gets messed up according to the industry standards.”
When the potatoes with Zebra Chip are fried they develop dark zebra-like bands. The discoloration results from changes in stored sugars that caramelized when fried. Potato products that show signs of the disease are removed before being packaged because of the appearance.
“It’s just a little thing that we have to kind of deal with to make sure that we always maintain a high quality standard of potatoes coming out of Idaho,” Olsen said.