Do I have Eutypa? or something else?

[mbrssmd]

This week while trying to catch up on shoot positioning and tying, I came upon the sudden appearance of this blight-ish appearance in around six of my 50 Cab Franc vines – lower leaves on shoots are fine, but leaves above first catch wire are spindly, yellowish, and cupping.

Another 3 or 4 CF vines show lesser/spotty signs, and I noticed a touch of it on one or two of my 50 Barbera vines. Nothing on my 35 petit verdot.

Based on reading I am assuming this is Eutypa – would the good folks on this forum agree? That said, I spent some time yesterday hunting for cankers (or wounds) on the double trunks, and have not yet located any.

The vines are 4 years old, VSP, cane pruning. I understand that Eutypa usually starts in a pruning wound? Does it then spread?

Some of these same vines were the ones hardest hit (i.e., somewhat spindly) in last year’s wicked Mother’s Day frost – coincidence? Last summer seemed disease free with basic 7-10 day basic Mancozeb/captan+sulfer spray regime along with focus on keeping good air flow in fruiting zone. Harvest was limited last year, both because of frost damage, and because it was year 3 for the vines.

I'm trying to read anything I can find, but I would welcome input from anyone with experience with Eutypa, or whatever they think this blight is.

As someone born in the first Eisenhower administration the prospect of simply pulling and starting over with replacement vines is, to say the least, rather disheartening, so I would also welcome thoughts on any other options. Many thanks.

 

[Rice_Guy]

I have not dealt with Eutypa

from the Midwest perspective I assume that yellowing with spindly growth is a viral infection, ,, which is spread by insects and or pruning tools that have been used on an infected plant. The treatment is to burn the plant, ,,, however I would look for local grape knowledge to find out if it is endemic where you live (ex county extension/ university disease lab/ larger vineyard)

A fungal infection is easier to deal with by spraying with a fungicide.

 

[wood1954]

I use two fungicides that are systemic that might help. Phostrol and tebuconazole , they both get into the plant tissue and will kill an infection, if it’s a virus you’re screwed, I think my plum trees had a viral infection and after 5 years two out of three seem to have defeated it

 

[Johnact]

Some pictures look like possible herbicide damage.

 

[balatonwine]

Suggest first reviewing this site, as it gives a very detailed description of symptoms and possible other similar issues (for example, you may simply have water logged soil such as I am having this year and can give similar early season symptoms) that may rather be the issue:

http://www.omafra.gov.on.ca/IPM/english/grapes/diseases-and-disorders/eutypa.html
In the end, if the issue does not self correct, and you should first wait to see if it self corrects, you may need a local professional to ***** your vines to determine the actual issue. Hope this helps.

Side note: Even if eutypa, such infected vines can take years to die. And can still create wine. In some cases, they can create very unique and interesting wines. So even if eutypa, I would not rush to tear them out.

 

[mbrssmd]

Thanks for all the thoughts. I found each one of them helpful. Just heard from our extension guy that he too thinks it's likely 2,4-D damage rather than eutypa. I had not thought of that, but it reminded me that a few weeks ago I was struck how the hayfield in the farm next-door was unusually weed-free, almost pristine, like I had never seen it in the last ten years...

So one sigh of relief while contemplating a future uncomfortable conversation.

 

[balatonwine]

I was struck how the hayfield in the farm next-door was unusually weed-free, almost pristine, like I had never seen it in the last ten years...

So one sigh of relief while contemplating a future uncomfortable conversation.

Oh.... dear.

I actually have had Eutypa. I removed it as an issue by changing my behavior. Such as changing when I trimmed my vines and other vineyard management practices.

Changing (and improving) my own behavior was actually very easy.

But asking someone else to change their behavior..... Oh.... dear.... ☹

 

[Snafflebit]

All of the Cabernet are highly susceptible to Eutypa. It looks suspicious but Eutypa usually appears in older vines. I have attached some examples from the vineyards I work with. If you are willing to cut into a damaged cordon. Look for the telltale wedge shaped darkened cross section.
The way to “treat” eutypa is to cut 6” past the damaged wood and retrain your cordon. It is a slow disease so you could manage this over a few years. I seal big pruning wounds with Doc Farwell’s seal and heal mixed with 5% by weight boric acid powder. i.e. roach poison

 

[TomC]

Thanks for all the thoughts. I found each one of them helpful. Just heard from our extension guy that he too thinks it's likely 2,4-D damage rather than eutypa. I had not thought of that, but it reminded me that a few weeks ago I was struck how the hayfield in the farm next-door was unusually weed-free, almost pristine, like I had never seen it in the last ten years...

So one sigh of relief while contemplating a future uncomfortable conversation.

I hope that you have a cooperative neighbor. I have been dealing with the same issue; e.g. pesticide drift into my vineyard from the farm next to me. It has been an ongoing problem for the last ten years. I informed him of the issue and provided various literature outlining the sensitivity of grapes to herbicides and his responsibility. This year, he planted soybean and burned down the fields with a herbicide (suspected 24D based). My small vineyard (100+vines) was damaged severly from what I think was a heat inversion drift of the herbicide. I filed a formal complaint with the Pa. Dept. of Ag.. They responded promptly, collected samples, took pictures of the damage, and surveyed his fields relative to my vineyard. I was advised that they will examine his spray records and submit my vine samples to their lab for analysis. If they determine that his spray is responsible for the damage, they will take appropriate action. I will be advised of the lab results; but NOT any actions against him. My only recourse is civil litagation!
About the Eutypa dieback, it is a real threat. Especially, to vines that have been weakened from herbicides. As Snafflebit pointed out, prune as late in the season as possible. On two year or older wood, seal the cuts to prevent infection. And, once the disease is evident, prune back to good wood. I have had to cut my Chambourcin vines almost to the ground in an attempt to regrow.