Idaho Potato Cyst Nematode Questions and Answers

Q: What is Potato Cyst Nematode (PCN)?
A: PCN is a major pest of potato crops in cool-temperate areas, and is recognized as one of the most difficult potato pests to control.

Q: What does PCN do?
A: The symptoms that potatoes show when attacked by potato cyst nematodes are not specific. Patches of poor growth generally occur in the crop, sometimes with yellowing, wilting or death of foliage. Even with minor symptoms on the foliage, potato size can be affected.

Q: Have any of the symptoms associated with PCN been seen in Idaho?
A: No

Q: Where in Idaho was PCN found?
A: A sample comprised of tare dirt from a grading station in Blackfoot, Idaho was determined on April 13, 2006 to contain PCN. That discovery prompted the Idaho State Department of Agriculture and the U.S. Department of Agriculture's Animal and Plant Health Inspection Service to launch an immediate investigation to determine the source of PCN.

Q: Did PCN originate in an Idaho potato field?
A: We don't know. We do know that the tare dirt from the grading station may have originated in an Idaho potato field, but we don't know that for sure, and there are other possibilities, too.

Q: What other possible sources are you exploring?
A: PCN may have come to Idaho on machinery, clothing, wind, wildlife or other means. We are exploring each of those possibilites. We are also looking at seed sources as a possible factor. None of the possibilities we are exploring has yielded additional PCN samples.

Q: How many positive PCN samples have you collected?
A: Only one -- the original sample of tare dirt -- has tested positive for PCN. None of the other more than 2,000 soil samples tested since the original PCN discovery has yielded new positive cases.