Grapevine red blotch virus found (and eliminated) in UC Davis Foundation Plant Services vineyard

According to the Foundation Plant Services (FPS),   Russell Ranch 2017 Virus Test Status:

On December 20, 2017, Foundation Plant Services (FPS) announced that Grapevine Red Blotch Disease, caused by Grapevine red blotch virus (GRBV), has been found in the Russell Ranch Vineyard (RRV).

All affected vines (only five of 4,132 vines in RRV tested positive for GRBV) have been removed and destroyed.

FPS is carefully monitoring the vineyard blocks in which GRBV has been found and additional testing has been implemented to ensure that any occurrence of disease is immediately detected and contained.

Russell Ranch vineyard has been tested for GRBV since 2013 and this is the first time it has been detected. While FPS is always committed to maintain foundation material at the highest standard, additional precautions are being implemented to prevent the spread of this disease.

To that end:

1. Every grapevine in RRV has been tested for GRBV.
2. The five GRBV positive vines have been removed and destroyed and are being monitored for regrowth.
3. All mother vines and vines related to GRBV positives tested negative in every case, indicating that this is a field transmission of GRBV.
4. Additional spray treatments specifically targeting the vector have been applied and a more comprehensive program for control of the vector is being developed.
5. Vitis spp. in proximity to RRV have been tested; positive vines have been removed and destroyed.
6. Material from these plants was distributed prior to the last negative test date, indicating that material was likely GRBV-free at the time of distribution. Nevertheless, the one customer who received material from these vines has been contacted by FPS.
7. The one vine that tested positive in the Classic Foundation was removed.
8. Preliminary sequence analysis showed high similarity (99% identity) to GRBV isolates from two different groups which indicates separate infection events.

Moving forward FPS will be even more vigilant. Visual inspections will be conducted more frequently.

All vines in RRV will be tested for GRBV annually by composite testing. Classic Foundation selections will be subject to regularly scheduled maintenance testing as well as testing as needed prior to distribution.

A collaborative approach from FPS, nurseries, and vineyards is our best defense to protect grapevine material from exposure to viruses. FPS is committed to maintaining the highest testing standard for our foundation vineyards and making every effort to keep you informed as new information becomes available.

Click here to read the official press release from Foundation Plant Services

According to: Foundation Plant Services, University of California, Davis:

Foundation Plant Services (FPS) is a self-supporting service department in the College of Agricultural & Environmental Sciences at the University of California, Davis. The FPS grape clean plant program was created in 1958 as a cooperative effort between the university, the USDA-ARS, and the wine and grape industry of California.

FPS plant material serves as primary source material for commercial increase of grapevines for the grape industry. The program is primarily geared toward the distribution of small quantities of commercially-important propagating stock to nurseries and others, who increase the stock for sale to commercial producers of grapes and grape products. The FPS collection currently contains over 750 grape varieties and 1200 clones (selections), which represent all regions of the United States and the world.

The Russell Ranch vineyard is 100-acres on the UC Davis campus. It set a national standard for grapevine foundation material in the United States at a rigorous new level. All vines planted at Russell Ranch must go through a testing scheme designated “PROTOCOL 2010”. To qualify as Protocol 2010 plant material, the vines must have been generated using microshoot tip culture and be tested for an extensive list of pathogens. The first vines to qualify as Protocol 2010 vines were rootstocks, and were planted in 2011. There are now over 1000 vines planted at Russell Ranch that are starting to produce plant material for grapevine nurseries for a new, clean source of planting material for growers nationwide.