Lawn treatment damage to young grapevines

[kwstone]

I have 2nd year grafted Petit Verdot and Cab Sauv vines in my backyard that were doing well until a recent treatment by my lawn company 48 hours ago on friday 4/30. The attached photos were just taken. I was not paying attention to their schedule and did not tell them to avoid the area. Last year all vines were in blue-x shelters and experienced no notable damage from the same lawn applications throughout the year. The vines pruned back to the trunk with 8-12" new shoots were hit hardest, drooping over away from the sun with leaves closed up. Initially I thought it was a foliar overspray issue because the vines pruned at the 30" fruiting wire showed no signs of stress until today where the shoot tips are beginning to wilt. This suggests possible root zone uptake? According to the company, the spray consisted of the ingredients below. I have contacted them asking for more specifics on the products and waiting for reply. I've attached 2 photos, one of a vine pruned back to the trunk past winter, and another pruned at the fruiting wire.
Assuming there was no post emergent product in their spray, could pre-emergent and fertilizer cause such a reaction, and is there anything I can do to help the vines recover? The soil is dense clay, so I'm hesitant to keep the root zone saturated due to very slow drainage at that depth. Would it help to shade the vines? I know it's probably wait and pray situation, but any guidance on path forward or thoughts on the mode of damage is much appreciated. Thanks.

Crabgrass Pre-emergent
30-0-0 Liquid Fertilizer
Custom Micro Nutrients Blend

 

[SheridanVines]

A closer picture would help but it definitely looks like herbicide damage. A crabgrass preventer is probably a group 3 herbicide. Some of them are labeled for grapes, but if it gets on green growth it will cause damage. It is possible some has been take up by the roots as well. The grapes probably won’t die and will grow out of it. You’ll just have to wait for them to metabolize the herbicide this year. Depending on how long that takes you may have to prune back to 3 buds and start over next year.

 

[Vern]

You have 24-d damage. This is the main herbicide in most lawn weed control products. Check all product labels and don't use any where near grapes. I have damage when neighbors sprayed 100 yards away. They should recover. Mine looked worse than yours and recovered.

 

[BigH]

Second pic shows some pretty clear 2,4-D damage. Leaf blistering, distorted veins, and deformed leaf edges are the giveaways.

This could be from your lawn company, or from a 2,4-D product being applied to a neighbors lawn. 2,4-D evaporates and can drift hundreds of yards. 2,4-D is a post emergent herbicide used for control of broad leaf weeds. I don't see it listed in your post, but it is present in nearly all weed-and-feed like products that control dandelions.

H

 

[SheridanVines]

Second pic shows some pretty clear 2,4-D damage. Leaf blistering, distorted veins, and deformed leaf edges are the giveaways.

This could be from your lawn company, or from a 2,4-D product being applied to a neighbors lawn. 2,4-D evaporates and can drift hundreds of yards. 2,4-D is a post emergent herbicide used for control of broad leaf weeds. I don't see it listed in your post, but it is present in nearly all weed-and-feed like products that control dandelions.

H

That’s true. It might not have been in their tank mix, but if they didn’t clean their tank really good (likely that they didn’t) from the last place the grapes probably got just enough of a whiff of 2-4D they showed injury. I had some drift over a half mile and get mine last summer.

 

[Snafflebit]

If it is specifically for crabgrass, I am guessing they sprayed Turflon ester. But the directions still say avoid grapes

Use Restrictions and Precautions Do not apply TURFLON ESTER directly to, or otherwise permit it to come into direct contact with cotton, grapes, peanuts, soybeans, tobacco, vegetable crops, flowers, citrus, fruit or orchard trees, shrubs or other desirable broadleaf plants. Do not permit spray mists containing TURFLON ESTER to drift onto such plants.

Edit, never mind I see your lawn company spread preemergent. turflon isn't preemergent

 

[kwstone]

Thanks everyone. My first thought would have been 2-4d as the most commonly used herbicide for broadleaf control in turfgrass, but I thought that was a post emergent herbicide, not pre-emergent? I also added closer up photos I think tell the same story. First 2 photos are the same vine with growth 30" off the ground, which has all the characteristics of 2-4d. The 3rd photo is a vine that was pruned back to trunk last winter with growth lower to the ground. It doesn't have the blistering, distorted edges, or deformed veins, the leaves are just curled up away from the sun.
At any rate, knowing I've got herbicide injury of some kind, should I continue my fungicide spray schedule as normal, at least for the lesser damaged, or would that further stress the vines? Thanks again.

 

[CTDrew]

Agree that you have herbicide damage. I would apply your fungicides as you normally would. Even on healthy vines, fungicides will not stress plants but only boost overall plant health, particularly systemic fungicides.

 

[balatonwine]

Even on healthy vines, fungicides will not stress plants but only boost overall plant health

Umm.... No.

The copper in Bordeaux mix can harm young vine leaves.

And sulfur sprays can damage vines in high temps.

Only to name two issues.

particularly systemic fungicides

And those are not an option for Organic farmers. So.... the world is far more complicated than you are suggesting. Just saying.

 

[kwstone]

Thanks, I sprayed a myclobutanil/mancozeb combo yesterday on schedule at mid range label rates with no issues despite temperature reaching 90. Growth has basically ceased on the lesser damaged vines, but I’m sure all new shoots on ground level vines are toast.
Lesson learned that will not be repeated!

 

[kwstone]

I’m in the Richmond VA area by the way. Brutal humidity 24/7 awaits!

 

[CTDrew]

I’m in the Richmond VA area by the way. Brutal humidity 24/7 awaits!

I would definitely apply your systemics as you usually would in rotation by FRAC number- manzate, forum, quadris, etc. whatever use spray normally. There are well documented plant health benefits to all these products. I am not organic but if you are using Coppers and Sulfurs they are preventatives only and to clarify they don’t aid plant health and weren’t what I was referring to. Actinovate does though and if you have access to that it can be added in as well. Keep us posted as the season goes on.

 

[kwstone]

Update from lawn company- they insist they never use 2-4d in any treatments, but that the last application contained triclopyr, so there it is.