Researchers say populations of potato psyllids-vectors of a new crop disease to the region called zebra chip-are growing dramatically in the Columbia Basin.
"The psyllid is showing up in a lot of places in the Columbia Basin, and in some traps in very high numbers," said Andy Jensen, an entomologist who coordinates research for the Oregon, Washington and Idaho potato commissions.
Zebra chip, which arrived for the first time in the Pacific Northwest last season, is caused by the Liberibacter bacterium. It reduces potato yields and renders tubers unmarketable with bands that darken when fried.
Despite the increasing psyllid pressure during the past couple of weeks, Phil Hamm, an Oregon State University plant pathologist, believes the disease shouldn't cause major problems for growers who stick with insecticide programs.
"You cannot stop them from coming in your field, but you better not let them colonize," Hamm said. "I expect we'll see additional numbers of psyllids in the next three weeks."
SOURCE: John O'Connell, Capital Press
http://www.capitalpress.com/newsletter/JO-PsyllidUpdate-082712