In Oregon’s Columbia River Gorge, the biggest disease in the sweet cherry crop is tomato ringspot.
The viral infection, transmitted by nematodes, causes leaf rosettes, lower production and, eventually, dead trees.
“You’ve all probably got this,” said Ashley Thompson, Oregon State University Extension specialist, to the 100 or so growers attending the annual preharvest cherry field day tour in The Dalles. The tour also covered management of challenging varieties, shifting housing regulations and other topics.
The orchards in the hills surrounding The Dalles — Oregon’s sweet cherry hotbed — have other tree illness, too, such as X-disease, prune dwarf virus and cherry leaf virus, but tomato ringspot is the most prevalent.
Symptoms of tomato ringspot virus include rosettes — small leaves growing in tight clusters — and enations — darkened scaly splotches on the underside of leaf spines. The pathogen can cause smaller and later-ripening cherries, and it can eventually kill the tree.
“It makes deciding when to pick … more difficult than it needs to be,” Scott Harper, a Washington State University virologist, told the group.
As with many viruses, the slow-spreading pathogen can remain in the plant for many years before causing symptoms, and it has no cure, Thompson and Harper said. Treatments include removing trees and controlling nearby weeds that could harbor the dagger nematode, the species that transmits tomato ringspot.
The tour group also visited blocks of Regina, Kordia and Coral Champagne. Warehouses like the three varieties because they pack and market well, but they pose grower challenges.
Orchardist Ian Chandler aims for 6–8 tons per acre for Regina and Kordia but struggles to balance production and fruit size with both, especially on precocious Gisela 6 and Gisela 12 rootstocks. His supervisor, Artemio Barreja, said he prunes aggressively to encourage second- and third-year wood, and he uses Retain to extend the bloom window for better fruit set.
However, Regina picks late and hits a relatively profitable market window, which lets him extend his season to entice workers.
Elsewhere, growers discussed a host of changes to Oregon’s labor housing laws.
Columbia Gorge Fruit Growers reminded employers that labor camps now require nitrate testing for private wells, mattress covers and carbon monoxide sensors. Starting in 2027, they will have minimum ambient temperature restrictions that in almost all cases require air-conditioner units during cherry season and at least one toilet for every 10 occupants, down from 15 currently.
More than 80 percent of the state’s ag labor housing is located between Hood River and The Dalles in the Columbia River Gorge. •
