Nina Zidack, director of the Montana Seed Potato Certification program, and her crew of seed potato inspectors walk the walk across the Big Sky Country of Montana every summer.

The teams patiently and meticulously traipse across more than 10,000 acres of Montana farmland, taking leaf samples and visually inspecting the seed potato plots for any signs of distress or disease. Tubers harvested from a nuclear plant the previous year are planted as a family unit in a seed plot the following year, Zidack said.

"Ten leaves are picked per family unit and brought back to the lab and tested for Potato Viruses X, Y and A," Zidack said. "If any family unit is positive for those viruses, then we give that information back to the grower, the location of that family unit and they will go and rogue it out."

The seed potato crop is visually scanned three times in the course of the growing season. Almost all of Montana's potato crop is produced for seed, and, as such, it is imperative for the fiscal health of Montana's seed potato industry that any plants showing signs of bacterial or viral infections be eliminated.

"Our most important market is recertification," Zidack said. "We really specialize in early generation, low-disease seed and so a lot of the seed we sell to Idaho, Columbia Basin, North Dakota, Wisconsin and Colorado is actually recertified, (and) grown for another one to three years in those states."

As if this year’s threat of potato psyllids, liberibacter and zebra chip disease were not enough for Pacific Northwest (PNW) potato growers, now comes a ban on PNW potatoes in South Korea.

The ban went into effect Aug. 17. South Korea expressed concerns about the potential introduction of psyllids and liberibacter, the bacteria that causes zebra chip, with the importation of potatoes from Oregon, Washington and Idaho.

According to a government spokesperson, recent bilateral plant health negotiations in San Francisco between a South Korea delegation and the USDA’s Animal and Plant, Health Inspection Service (APHIS) produced no agreement and the ban remains in place pending future negotiations.

In 2011, Korea imported 90,000 tons of fresh and frozen potato products with fresh potatoes comprising 30 percent of the total. Imported fresh potatoes are used primarily in snack food manufacturing, according to a report released by the USDA’s Foreign Agricultural Service.

The United States imported 16,645 tons of fresh potatoes in 2011 to South Korea, according to the Korea International Trade Association (KITA).

Previous quarantine regulations concerning pest control imposed by South Korea prohibit 27 states, including Idaho’s Bingham and Bonneville counties, from exporting fresh potatoes to South Korea.

National Potato Council president John Keeling said that U.S. exporters to South Korea could provide additional short-term actions in terms of testing and oversight to alleviate concerns about psyllid transmission to South Korea and open the market in the short term.

“In the long run, they’re going to have to open the market based on the fact that science would say this (zebra chip) can’t be vectored to their potato crops,” Keeling said.

“The good news in all this is that I think the Koreans, in the long-term, need and want American potatoes — particularly chipping potatoes because they actually have to close plants over there. So you have, at some level, the interest or goodwill of the Koreans as a part of this and that makes it different from some of these other trade disputes,” Keeling said.