Blueberry scorch virus, a pathogen that can weaken or kill plants, has been confirmed in two Central Washington fields.
More common in Northwestern Washington and British Columbia, Canada, the virus has no cure and is spread by a specific breed of aphid or by infected nursery stock, according to a news release from Washington State University Extension.
Symptoms, such as shoot tip dieback on isolated branches followed by blossom blight, usually take one or two years to manifest and sometimes resemble blueberry shock virus or even frost damage, according to the release.
Scientists urge growers to keep an eye out for the disease, manage aphids diligently and have their plants tested.
The Washington Blueberry Commission is offering free testing for blueberry scorch virus and blueberry shock virus — up to 30 samples for each farm paying assessments. Phyto Diagnostics Co. of British Columbia will conduct the testing. All results will be kept confidential, the release said.
Growers should sample symptomatic plants and a few nearby with the following protocol:
—Collect five leaves close to the symptoms, pat them dry with a paper towel and place them in a sealable plastic bag.
—Label the plant and the bag on the bottom right corner.
—Keep samples cool, but don’t freeze them.
—Fill out a Phyto Diagnostics sample submission form, found here: phytodiagnostics.com/Guides.html.
—Ship samples and submission form to Phyto Diagnostics, 9381 Ardmore Dr., North Saanich, Britisth Columbia, V8L 5G4, Canada.
—Include two copies of the required import permit, available from the Washington Blueberry Commission or Walters Ag Research.
—Expect results in about two weeks.
Growers are advised to quickly remove plants that test positive and to monitor the field closely for at least three years.
Researchers expect to soon publish instructions for vector monitoring and management, the release said.
For more information, contact Walters Ag Research by phone at: 360-420-2776 or by email at: waltersagresearch@frontier.com.
Benton County, Washington, growers may contact Gwen Hoheisel, WSU Extension regional specialist, by phone at: 509-786-5609 or by email at: ghoheisel@wsu.edu. •
