Courtesy Texas A&M UniversityZebra chip causes potato tubers to store sugar rather than starch. When potatoes are cooked, as in potato chips, the sugar caramelizes, turning brown.Researchers have found a single potato plant with classic zebra chip symptoms at the University of Idaho's Kimberly Research and Extension Center.
Samples were sent to the university's main campus in Moscow for testing, but Erik Wenninger, an assistant entomology professor, writes in a PNW Pest Alert Network email that he's confident of the diagnosis.
Classic symptoms include aerial tubers, pink coloration of leaves, leaf curling and internal discoloration of tubers.
The plant was pulled from the field and destroyed.
This is the same field where an adult potato psyllid, which can vector zebra chip, was picked up on a trap earlier this month.
It also marks the first time this season that zebra chip has been confirmed in a Pacific Northwest potato planting.
Psyllid samples collected on July 3 from two fields in Twin Falls County tested positive for liberibacter, the causal agent of zebra chip.
In addition, two potato psyllids were collected from yellow stick traps in Elmore county July 15 and sent to the Parma Research and Extension Center.
Two additional adult potato psyllids were trapped in Minidoka County and taken to the Kimberly Center. They were sent to Moscow for further testing.
For more information on psyllid scouting, visit the Kimberly Center.
Zebra chip is harmless to humans but causes potato tubers to accumulate sugar rather than starches. When heated, such as during frying of potato chips, the sugar caramelizes, turning brown.