Photos of Grapevine Red Blotch Disease

Trial Sites

All images in the following table are of specific vines in locations which are under evaluation with grant funding provided by the American Vineyard Foundation. Vines in the photos tested positive for grapevine red blotch associated virus (GRBaV) by PCR-assay. They also tested negative for 20 other grapevine viruses and the bacterium that causes Pierce's disease.

To insure foliar symptoms of grapevine red blotch disease can be associated with a single virus - GRBaV - UC Foundation Plant Services tested all vines using the current "full panel" of PCR assays. As stated above, each vine tested negative for 20 grapevine viruses (including all grapevine leafroll roll associated viruses). Fewer than half the vines tested positive for grapevine rupestris stem-pitting associated virus; a virus that has not been shown to cause significant disease in grapevines.

Photos from Grower Sites are located below the Trial Sites pictures.

Click on the photos to enlarge. Information about each image is included in its file name under the photo.

Grower Sites
All images in the following table are of vines observed in different vineyards and are not under evaluation for the project. Vines in the photos tested positive for grapevine red blotch associated virus (GRBaV) by PCR-assay.  Unless otherwise indicated, vines have not been tested for the presence of other grapevine viruses, thus foliar symptoms of grapevine red blotch disease may be affected by co-infections.

Click on the photos to enlarge. Information about each image is included in its file name under the photo.