ng stocks, either nursery materials or from top-working plants with wood from field sources. Education on how to stop the spread of the disease will be a key component of red blotch outreach efforts.
The movement of vines and the ODA plant quarantine system, which states that it is illegal to move known infected plant materials into or within the state is an important component in stopping the spread of infected vines. 95% of Oregon grapevine nursery stock comes from California, therefore potentially infected plants may have arrived prior to the testing for GRBaV. Nursery managers from Sunridge and Duarte noted that the new Grapevine Foundation Block at Russell Ranch (where all material has been tested using the 2010 protocol for grapevine disease testing) will become the primary source of wood for certified nurseries. All material at the Russell Ranch tested negative for GRBaV in 2013. This part of the discussion generated two practical recommendations to grape growers:
- Plant only certified grapevine materials. Vines from Russell Ranch and Clean Plant Center Northwest (Washington State University-Prosser, WA) are certified free of GRBaV, Grapevine leafroll associated viruses and viruses causing trunk diseases.
- Unless individual vines are tested for known viruses, do NOT propagate from any vines in your vineyard. The risk of spread of viruses, even from asymptomatic vines, is too great.
Geoff Hall, viticulturist from Ste. Michelle Wine Estates stated that WSU faculty and industry associations consistently reinforce the need to exercise caution and utilize proper practices when managing the spread of viruses in vineyards, which applies to Oregon growers as well.
Outcomes from this important meeting include:
- A letter has been drafted to Oregon Department of Agriculture Director Katy Coba requesting that grapevine red blotch associated viruses be added to Oregon’s plant quarantine list
- ODA plant pathologists together with the Oregon Wine Board will apply for an ODA specialty crop block grant to do a survey of red blotch in Oregon vineyards
- OSU will continue to provide extension resources on grapevine viruses
- This group will serve as a vine improvement committee for the Oregon wine industry
- There is a need to enhance grower outreach and education on grapevine viruses
- Identify resources to increase virus testing capacity in Oregon
This group has agreed to meet again in December 2015.
- ODA’s grapevine quarantine regulations can be found at http://arcweb.sos.state.or.us/pages/rules/oars_600/oar_603/603_052.html
- National Clean Plant Network Red Blotch Fact Sheet: http://cemendocino.ucanr.edu/files/165430.pdf