Vine disease

Our vineyard is in Ventura county, CA, which is ground zero for Pierce’s disease. After harvest I noticed one of the Grenache died suddenly, without showing typical leaf burn (which is hard to distinguish from vines going dormant in the fall). I cut some cordon off to send for Xylella testing and noticed a wedge-shaped canker in the wood.

The lab doesn’t test for wood canker diseases, such as eutypa, phomopsis, esca, etc, but looks like it to me. What do you guys think?

The image shows sections of cordon starting near the trunk on the left and moving out. The first section is normal, but starting with the arrowed section there is a dark streak extending from the bark to the pith that becomes larger and wedge-shaped progressing right to the end of the cordon. (The image is upside down - the dark streak faced upward on the vine)
canker.JPG
I cut and sealed the trunk two nodes above the graft union. It looked normal there and if shoots form in the spring hopefully a new vine can be trained.

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Have you ever noticed sharpshooters in the vineyard? Are you near any citrus? Near a riparian areas? If not, I would be less worried. You might want to reach out to Adam at Ojai Vineyard - he might be able to offer some good insights.

Cheers

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Yes we have glassy-winged sharpshooters here! Adam’s vineyard guy does our heavy work and is very knowledgeable, but so far PD is an insoluble issue*.

The sharpshooters are invasive - originally from the South East. Evidently they don’t colonize areas with colder winters, but do very well in S. California up to Southern Santa Barbara county.

So far only one vine has been lost to lab confirmed PD. As far as I can tell PD doesn’t cause a wood canker as shown here.

*There is now a product to treat and/or prevent PD: an injectable phage virus that targets xylella bacteria. However running the numbers it is very expensive and may not be practical. Andy Walker at UCD bread PD-resistant vines that are ~95% vinifera. These aren’t available yet but Adam has a test vineyard with these hybrids in Ojai.

Sure looks like eutypa.

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Thanks Casey - I was hoping you would respond!