# Unexplained sudden wilting 3 year old Merlot



## vtoddw (Apr 23, 2022)

Hello,

I have a 3rd year Merlot vine in a row of 6 Merlot vines that has sudden wilting on the cordon but the growth from the roots is fine and healthy. None of the other 24 vines have this problem, it was growing fine until last week all the shoots and leaves became limp and turned upside down. I've verified the irrigation is flowing fine on this vine, same as the rest. Only difference is there is a lot of Bermuda grass around the base. Is it possible this is all due to the nutrients / water the grass is stealing? Or could it be a disease, like verticillium wilt?

Here are some pics showing the wilting, the healthy growth at the base of the vine and the neighboring vines which look fine.









Thanks in advance,
Todd


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## balatonwine (Apr 25, 2022)

I had a vine do that once. Base had healthy shoots, but those at the wire were got limp in a week.

Found a big fat wood boring beetle grub in the main stem.

Not saying this is your exact issue, but if you have some healthy lower stems, may be wroth to just cut off the current main stem and try to retrain a new stem from the lower healthy ones. If those also die off, then the vine may simply die. They do that for many reasons. I have a few thousand vines, and every year a few simply die.


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## vtoddw (Apr 25, 2022)

balatonwine said:


> I had a vine do that once. Base had healthy shoots, but those at the wire were got limp in a week.
> 
> Found a big fat wood boring beetle grub in the main stem.
> 
> Not saying this is your exact issue, but if you have some healthy lower stems, may be wroth to just cut off the current main stem and try to retrain a new stem from the lower healthy ones. If those also die off, then the vine may simply die. They do that for many reasons. I have a few thousand vines, and every year a few simply die.



Thanks very much for the reply. Yeah this vine never had very good vigor and I don't much like the structure so I was planning on cutting off the trunk since I saw the wilting and letting both (or one) of those become the new trucks (I've had better production with vines that have dual trunks than a single trunk, not sure what that's called). Unfortunately since I only have 30 vines I fret at every single vine death, which has been about 1 per year for various reasons. 

I appreciate your suggestion, I'm wondering if you can advise whether or not I should cut the trunk this time of year or wait for dormancy in the winter. I've never actually cut any trunks or cordons during the growing season, only new shoots, so I just don't know if the bleeding will harm the vine.


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## balatonwine (Apr 27, 2022)

vtoddw said:


> Unfortunately since I only have 30 vines I fret at every single vine death, which has been about 1 per year for various reasons.



Understand. I have the same for my 30ish tomato and pepper seedlings I raise from seeds each year. I also fret over those I loose.



vtoddw said:


> I'm wondering if you can advise whether or not I should cut the trunk this time of year or wait for dormancy in the winter. I've never actually cut any trunks or cordons during the growing season, only new shoots, so I just don't know if the bleeding will harm the vine.



I can not advise. I do not have enough facts to advise to provide a complete cost benefit ratio.

But personally, simply if it were my vine, I would cut the vine now. For any of the following thoughts:

1) If a disease, it may have come in from a sap sucking insect. Thus maybe not fully worked its way down the stem. So major surgery now may be like cutting off a limb of a mammal affected from gangrene. Stops the spread of the infection. Lots of blood loss, a limb lost, but saves the body.

2) Plants deal with major injury better than we give credit to. While there are best practices for when and how to trim, they can be actually quite variable. Cutting late in the season often is frowned upon for some incorrect reasons. The main reason is that the plant will loose some vigor from some sap loss, and for commercial reasons such lost vigor is to be avoided. But sap loss is really not that big an issue for plant health as most suspect. It is more an issue for vigor. Plants have mechanisms to deal with damage. In fact, cutting too soon in the season may be worse than cutting too late. Sap bleed out is simply one method assisting the plant to avoid infection of the wound. To help the plant simply do not make major cuts if you expect rain within 10 days post cut. In that time frame the plant should have sealed the wound enough to get along without risks. But, yes, that sap loss does affect the vigor and strength of the plant. If I do major cuts on a spring plant, I nip off all fruit that year. Gives the extra energy lost from the cut to heal rather than trying to make fruit.

3) Better to find out now, this year, if the vine will make it or not. Let it tough it out now. And if it can not cope, you can replant this fall. If you try to baby it along all this year, and loose it next year, you actually loose a year or more of production of the eventual new vine you had to buy anyway.

Hope this helps


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## vtoddw (Apr 27, 2022)

That helps immensely. I was thinking along those lines as well, if I wait until dormancy then chances are the plant will die by next spring and set me back yet another year, so I might as well take the risk now.

I went ahead and cut it, first at about the middle of the trunk, then noticed there's no sap oozing so cut it progressively further down until I ended up reaching the base, and no sap. Seems like this plant isn't even pushing water up at the base of the vine.

Here's a pic before I cut it, as you can see all foliage on the cordon is dead and dried up completely, but the lower growth coming from the ground looks very healthy.

And here's another pic showing the stump left after cutting it. I cut the trunk and cordon up into small pieces to see if there was any evidence of fungus ,worms or beetles but found nothing obvious, so this is still a mystery. I'll be sure to update this post when any noteworthy changes occur as it may help someone at some point, although all I have now are more questions than answers...

Thanks again for your help, I really appreciate it!


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## Fox Squirrel Vin (Apr 27, 2022)

vtoddw said:


> That helps immensely. I was thinking along those lines as well, if I wait until dormancy then chances are the plant will die by next spring and set me back yet another year, so I might as well take the risk now.
> 
> I went ahead and cut it, first at about the middle of the trunk, then noticed there's no sap oozing so cut it progressively further down until I ended up reaching the base, and no sap. Seems like this plant isn't even pushing water up at the base of the vine.
> 
> ...


That's really strange.


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## VinesnBines (Apr 28, 2022)

It looks like it has died back to the ground. These are on their own roots correct? Otherwise you have healthy rootstock.


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## vtoddw (Apr 28, 2022)

Yup, none of my vines are grafted, for whatever reason here in Temecula CA the nurseries don't sell grafted vines. It has dawned on me that this could be phyloxera, but the puzzling part is that there was no evidence of that above ground, the leaves looked normal until they went limp and started drying up, no bumps or anything. The other puzzling part is that the 3 shoots coming out or the ground are very healthy and growing vigorously. I've never encounter phyloxera before in the 8 years I've been growing grapes, so im not sure if this fits the pattern.


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## VinesnBines (Apr 28, 2022)

I thought of phyloxera but like you, I don't have any experience.


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## vtoddw (Apr 28, 2022)

I decided that salvaging one vine is not worth losing the whole vineyard, so the only way to be 100% sure was to dig it up. The good news, is that there is no sign of Phyloxera on the roots that I can tell. The bad news is that the Bermuda grass which has invaded my yard and was growing around the base of this particular vine appears to be weaving it's roots in between the vines. So my theory here is that the Bermuda grass was just stealing too much of the water and nutrients for the Merlot to support it's trunk. That still doesn't explain the healthy vine growth coming from the base, but I don't really know what else it would be at this point.

Here are some pictures showing my findings. As you can see the straw-colored Bermuda grass roots are weaving themselves right through the dark vine roots and there's no visible evidence of the beads that appear on the vine roots (at least form what I could find online).

Thanks to all for you help and feedback, I feel better now knowing that (as far as I can tell) I do not have a Phyloxera infestation.


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## VinesnBines (Apr 28, 2022)

According to my Vinesmith chart, Mad Dog Plus herbicide is best for Bermuda grass. The active ingredient is glyphosate but a more active formulation than Roundup. Since the vines are three years old there should not be a problem spraying around the trunks. Glyphosate won’t hurt the vine as long as you keep it off the leaves. I suggest killing out the grass ASAP.


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## vtoddw (Apr 28, 2022)

Thanks again, that's definitely the plan. I have actually been using Ornamec 170 this year, which has successfully killed it in many other spots in my vineyard, but I held off on treating this particular vine because that new growth coming from the ground was surrounded by the grass, so I was concerned about overspray. I actually just treated it last week with Ornamec 170 finally, since the growth at the base had reached a couple of feet above ground (I temporarily put a bag around the new shoots while spraying), so it's possible it would have been ok. 

If the Ornamec doesn't do the trick I'll definitely consider Glyphosate, although I'm admittedly apprehensive about using it ever since Roundup got linked to Cancer....but I imagine the Ornamec causes cancel as well and we just don't know it yet, what can ya do...


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## VinesnBines (Apr 28, 2022)

According to the chart Fluazifop-P-butyl the active ingredient in Ornamec is as good as glyphosate. And yes, they just haven’t been sued yet.
Paraquat is the newest evil. Oh well.
Good luck, wipe out the Bermuda grass and hope no other vines are affected.


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## Fox Squirrel Vin (Apr 28, 2022)

Dicamba is the one you really got to watch out for.


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## vtoddw (Apr 28, 2022)

VinesnBines said:


> According to the chart Fluazifop-P-butyl the active ingredient in Ornamec is as good as glyphosate. And yes, they just haven’t been sued yet.
> Paraquat is the newest evil. Oh well.
> Good luck, wipe out the Bermuda grass and hope no other vines are affected.



True true, thanks again, hopefully my learning experience here helps someone avoid the same setbacks in the future. In short, kill those dang weeds!


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## Fox Squirrel Vin (Apr 28, 2022)

Looking at your root pictures a bit closer.. there looks to be some nematode damage on the smaller roots. That 3201 photo, the lower roots near the bottom of your hand.. those yellowish bumps look like nematode damage to me...

I've edited my previous post, this is a product that works on them and is approved for grapes. Believe it or not but that's actually a good price for a product that is effective against nematodes.






Movento Insecticide - 1 Quart [264-1050] - $284.95 : Keystone Pest Solutions, Low price herbicides and pesticides


Keystone Pest Solutions Movento Insecticide - 1 Quart [264-1050] - Movento Insecticide (1 Quart) Movento Insecticide is a systemic insecticide that moves within plants to protect them from a broad range of insects, mites and nematodes above and below the ground, creating highly pest-resistant...



www.keystonepestsolutions.com


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## vtoddw (Apr 28, 2022)

Fox Squirrel Vin said:


> Looking at your root pictures a bit closer.. there looks to be some nematode damage on the older roots. That 3201 photo, the lower roots near the bottom of your hand.. those yellowish bumps look like nematode damage to me...
> 
> Bad thing about those guys is there are very few treatments for them and the one there is that seems to work is $1,300 a GALLON. I don't believe it comes in a smaller quantity.
> 
> ...



Wow, I hope not, that's extremely steep. I'm hoping that was just an optical illusion. Here's some cleaner pics without the dirt and Bermuda grass roots.


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## Fox Squirrel Vin (Apr 28, 2022)

image 5102.. Nematodes usually affect the smaller roots and the cause those segmented bumps. I can't tell 100% without them in front of me but something seems a bit off on those roots. There also seems to be little root growth for a vine that size but that can be due to soil fertility, available water, and fertilizer use.

I edited my previous post with a different product that is cheaper but may not be approved in your state. It is however approved for use on grapes. I completely forgot about it and it is a product I have used before mainly as a systemic insectacide on potatoes. It's a great product and works on phylloxera as well. Not saying you should use it, but this summer, if you have more issues, it might be worth looking into and if you do have another vine die, send it to your local ag extension office for testing. FYI, the OMRI approved products for controlling nematodes don't work. Maybe in a lab in a dish but I've never had any luck with them.


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## vtoddw (Apr 29, 2022)

Fox Squirrel Vin said:


> image 5102.. Nematodes usually affect the smaller roots and the cause those segmented bumps. I can't tell 100% without them in front of me but something seems a bit off on those roots. There also seems to be little root growth for a vine that size but that can be due to soil fertility, available water, and fertilizer use.
> 
> I edited my previous post with a different product that is cheaper but may not be approved in your state. It is however approved for use on grapes. I completely forgot about it and it is a product I have used before mainly as a systemic insectacide on potatoes. It's a great product and works on phylloxera as well. Not saying you should use it, but this summer, if you have more issues, it might be worth looking into and if you do have another vine die, send it to your local ag extension office for testing. FYI, the OMRI approved products for controlling nematodes don't work. Maybe in a lab in a dish but I've never had any luck with them.



That's a much more feasible price, I'll give it a shot because at this point it's really a guessing game. I looked up the various nematodes that affect grapes and it looks like there's 7 different species, not all of which would cause the Galls I was expecting to see: https://www2.ipm.ucanr.edu/agriculture/grape/nematodes/

The scary part is that it says on that site "Every precaution should be taken to exclude plant-parasitic nematodes if the area is free of them; once established, nematode infestations are permanent". I'm hoping Movento will prove that to be untrue.

I see what you mean by the banding in that photo. I have actually had about 1 unexplained vine death per year over the last 3 years, although about 20 ft away from this vine. I've also had a lot of stunted shoots on my zinfandel vines, plus leaf burning in September and October. 2020 was actually my first harvest I used for making wine, then 2021 my harvest was half the yield of 2020. I had previously chalked up the vine deaths, leaf burning, stunted shoots and lack of yield to mistakes I'd made with watering. Now I've got my watering down and I'm inspecting the vines daily to look for hanging or burned tendrils to ensure I don't underwater on the really hot days we get out here. The last two Labor days it hit 112 and 115 respectively.

I started thinking this year that the leaf burning may be more possibly due to Pierce's disease as I did see a sharp shooter in my vines in the last month. I've only seen one or two of them, they are very fast and hard to get a close up picture of them, so I can't really tell if it's a Smoke Tree or Glassy Winged sharpshooter based on it's head pattern. It doesn't help that my neighbor has a massive lemon tree and apparently those things love to overwinter in Citrus. 

Here are some pictures of 3 of my Zinfandel vines last year, not sure if this is Pierce's disease, vine stress due to lack of appropriate watering / nutrients or if it's possible due to Nematodes all along. I did lose one of these that looked very healthy last year, it went into dormancy winter of 2020 looking fine and then when I pruned it during the spring of 2021 the entire vine was hard wood all the way tot he ground. I feel like this leaf burning didn't start happening until Summer of 2021 but I only started taking pictures last year. Oddly enough the only vines I've seen with the leaf burning have been the Zinfandel and Thompson seedless (I have for eating- definitely not trying to make wine with those). The Merlot and Cabernet Sauvignon have not had this leaf burning, so I assumed it's just something Zinfandel are prone to. In the first picture that shows the whole vine you can see there are several stunted shoots, only the middle and ends of the vines actually grew and produced any fruit. In the last pic you can see the sharp shooter I saw earlier this month, but I couldn't get a closer shot.


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## vtoddw (Apr 29, 2022)

Correction, I was indeed taking pictures in 2020, here's the Zinfandel vine that was dead by spring of 2021 which I mentioned in the last post. I figured that it was because I got greedy and over cropped it, which I assumed is why I ended up with all that uneven berry ripening you see in the picture here. I have a new vine in it's place this year which is doing well, so assuming this was killed by Nematodes I'm guessing they may kill this one by next year too unless I can turn it around with Movento.


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## Fox Squirrel Vin (Apr 29, 2022)

Heat stress can cause uneven ripening. 115 degrees is HOT and hard on wine grapes. One way to manage heat stress is with water. Making sure they never dry out during the hottest periods is really really helpful. If you are waiting to see drooping tendrils, you are already stressing the plant and it will shut down parts of itself to save other parts. Get a cheap moisture meter rather than waiting to see signs from the plant that it needs water.

Fruit management- Limit the fruit production on young vines to vines closest to the basil wood of the spur, no more than one bunch per vine/spur and no more than 1 linear foot of fruit per 1/4 inch of trunk diameter till the vine is 4-5 years old. Green prune excessive unproductive vines to two buds from the spur or at least down to a 3-4 leaves if your grape producing vines do not have adequate growth (4-5') you can adjust this pruning when the plant is dormant. Excessive growth puts a lot of demand on the plant for sap and in high heat, the plant will struggle with the demand until the trunks are firmly established and are of significant diameter.

Give your vines some triple superphosphate. Phosphorus is involved in several key plant functions, including energy transfer, photosynthesis, transformation of sugars and stimulates root growth. Don't add any nitrogen unless you are seeing vigor issues.

That vine that died really didn't have a robust root structure so factor that with some pest related stress on top of heat related stress on top of a tired vine from producing too much fruit the previous year... You get the picture. Too much environmental stress.

If you are using a backpack sprayer you want to use 1 oz of movento to 4 gallons of water and you need to mix a tablespoon of a non ionic surfactant with it. Dawn dish detergent works in a pinch, I like to use Tween 20 (Polysorbate 20) try to keep it off the fruit, Movento warns about fruit damage from surfactants but focus on spraying the leaves and not the fruit. I like to spray in the evenings before sunset so the evaporation of the water is slower.


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## balatonwine (Apr 29, 2022)

vtoddw said:


> I decided that salvaging one vine is not worth losing the whole vineyard, so the only way to be 100% sure was to dig it up. The good news, is that there is no sign of Phyloxera on the roots that I can tell. The bad news is that the Bermuda grass which has invaded my yard and was growing around the base of this particular vine appears to be weaving it's roots in between the vines. So my theory here is that the Bermuda grass was just stealing too much of the water and nutrients for the Merlot to support it's trunk. That still doesn't explain the healthy vine growth coming from the base, but I don't really know what else it would be at this point.



This and other post comments are interesting, but sadly provide little value. Mainly because this is one plant. Thus one data point. And little to nothing can be extrapolated from one data point.

For example,

1) Bermuda grass: To start off, vines do not like competition in their under canopy root zone. Removing such competition is good practice to help with vine vigor. That being said, I did a multi year trial on a "no till" vineyard, with plenty of Bermuda grass and no vines died. They did have reduced vigor, but no deaths. So solely blaming Bermuda grass may not be accurate. But, again, removing under canopy weeds is a good idea. Many people today reach for some chemical spray. The "better live via chemistry" idea. Great idea in the 1950's for anyone, and still an excuse for Big Ag today. But growing issues are arising. You can decide what is best for you (I will not judge here). But, if you only have 30 vines, after you clear out the Bermuda grass, I might suggest to consider some simple, routine and free of cost mechanical soil tilling is all you need to do to keep your vines weed free and healthier. See video below.

2) Nematodes, etc.... : If you dig up any vine in your vineyard, you may find some root damage. Any wild critter has some disease load. Seeing root damage alone does not prove anything. Some plants may have more root damage than others. But... that maybe simply due to the fact the plant was already weekend for other reasons and can not fend of disease. Thus disease load may be a symptom of other issues that are causing illness, not a direct cause of the illness. Thus the presence or extent of nematodes really can have multiple causes. So is ambiguous.

3) Weak roots: The vine may have started off with a week root system. I have bought many commercial vines and some had very weak roots. I flagged them. And trimmed them to two buds for many years, beyond the trimming what "healthy" plants received. Plants with weak root systems to start need special attention to become healthy adult plants.

Above are just some issues to consider.

Hope this helps.

Weed free vine rows with a wheel hoe:


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## balatonwine (Apr 29, 2022)

vtoddw said:


> I decided that salvaging one vine is not worth losing the whole vineyard, so the only way to be 100% sure was to dig it up. The good news, is that there is no sign of Phyloxera on the roots that I can tell.



I hope you did not dig up your vine simply due to fears of Phyloxera that others may have made here. Because Phyloxera is endemic to the USA and exists pretty much anywhere there are vines. If you have Phyloxera on one vine you have them on all of your vines. Soil types and other mitigating factors allow some areas to remain functionally Phyloxera "free" structurally, and allow native rooted vines to grow mostly healthy (even if some succumb to the louse). So removing and killing one vine out of fear it will "infect others" from Phyloxera will have mostly zero benefit for your vineyard. If the vine was sick due to other issues, especially virus or bacterial disease, then removing it may have been a good idea. But to know that, for certain, you need to send the plant to a lab for analysis. To say otherwise, no amount of forum "_experts_" pontificating what _*they*_ think is the problem, or what you should do, based on their pontificates, is not worth a brass farthing.... or the Yankee equivalent: is not worth a damn.... (what is appropriate is depending on which side of the pond one is, and what is the level of censor at forums such as this as to what is appropriate language...  ).


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## Fox Squirrel Vin (Apr 29, 2022)

balatonwine said:


> I hope you did not dig up your vine simply due to fears of Phyloxera that others may have made here. Because Phyloxera is endemic to the USA and exists pretty much anywhere there are vines. If you have Phyloxera on one vine you have them on all of your vines. Soil types and other mitigating factors allow some areas to remain functionally Phyloxera "free" structurally, and allow native rooted vines to grow mostly healthy (even if some succumb to the louse). So removing and killing one vine out of fear it will "infect others" from Phyloxera will have mostly zero benefit for your vineyard. If the vine was sick due to other issues, especially virus or bacterial disease, then removing it may have been a good idea. But to know that, for certain, you need to send the plant to a lab for analysis. To say otherwise, no amount of forum "_experts_" pontificating what _*they*_ think is the problem, or what you should do, based on their pontificates, is not worth a brass farthing.... or the Yankee equivalent: is not worth a damn.... (what is appropriate is depending on which side of the pond one is, and what is the level of censor at forums such as this as to what is appropriate language...  ).


Trying to rejuvenate a vine that has issues when it is so much easier to replace it with a healthy one is not worth the effort, it wasn't a 20 year old plant. He can make plenty of new plants from the plants he has now without worrying about introducing anything from a commercial supplier. 

Removing the vine allows you to see into it's past and why it died and what you can improve on. He learned 2 things, the roots were less than sufficient so he needs to focus on methods to improve the root system, and, there looks to be some nematode damage. There is somthing causing his vines to brown and die so these learning experiences can be helpful to keep the rest of his vines thriving and improve on what he is doing. Nematodes are better to be controlled rather than wait until you are infested with them. Then they are much harder to deal with especially in a hot climate and sandy soil where they thrive. Trying to save plants after they have a severe infestation is much more difficult than preventing one. 

Improving 2 issues when you may have 5 is a 40% improvement that gives the plant more strength to deal with the other issues it may have and sometimes that is enough. If a plant is healthy below ground it is going to be much healthier above it, Above ground issues are easier to deal with because you can see them.

I do agree with what you are saying but, when a plant has stress from may issues, one single issue may not be enough to kill an otherwise healthy plant but it's enough to kill THAT plant because it is severely stressed due to roots, hot climate, soil pests, too much fruit for its age...


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## vtoddw (Apr 29, 2022)

Fox Squirrel Vin said:


> Heat stress can cause uneven ripening. 115 degrees is HOT and hard on wine grapes. One way to manage heat stress is with water. Making sure they never dry out during the hottest periods is really really helpful. If you are waiting to see drooping tendrils, you are already stressing the plant and it will shut down parts of itself to save other parts. Get a cheap moisture meter rather than waiting to see signs from the plant that it needs water.
> 
> Fruit management- Limit the fruit production on young vines to vines closest to the basil wood of the spur, no more than one bunch per vine/spur and no more than 1 linear foot of fruit per 1/4 inch of trunk diameter till the vine is 4-5 years old. Green prune excessive unproductive vines to two buds from the spur or at least down to a 3-4 leaves if your grape producing vines do not have adequate growth (4-5') you can adjust this pruning when the plant is dormant. Excessive growth puts a lot of demand on the plant for sap and in high heat, the plant will struggle with the demand until the trunks are firmly established and are of significant diameter.
> 
> ...



Thank you again for your invaluable feedback, I'm learning a ton here!

Fortunately 115 is not the average, it's usually between 90 and 104 here during any given summer day, but coincidentally the last two Labor Days were record breakers, not exactly trending in a good direction. 

Right now I'm deep watering my vines 2 gallons of water per vine twice a week via a slow drip line on a regular timer. I'm watching the tendrils and the color of the leaves to ensure I'm not over or under watering and they seem to be doing well at the moment. When it gets hotter, in May or June I'll likely increase that to 4 gallons per vine twice a week. My biggest takeaway from last year, during which I was initially watering once a week with 2 gallons per vine, was that although they may look fine in the spring on the average days, the vines will need extra water on the above average hot days, so it's not a just a passive process where I set the timer and wait for harvest. 

I also learned last year by researching the leaf burning and discoloration on my Zinfandel that they appeared to be lacking in Phosphorus, so now that you corroborated that I feel much better (as I was thinking it was Pierce's disease - which it still could be, we'll see) so back in late February just before bud break I gave the 5 mature Zinfandel vines (excluding the newly planted vine) 2 tbsp of "Easy Peasy Super Phosphate" 60% 0-46-0 Phosphorus and worked it into the soil and soaked for a while. Unfortunately the bag doesn't have explicit instructions for Grapes so I had to guess how much based on it's broad recommendation and stayed on the low side as I don't want to kill the vines. I also gave all mature vines (none of the 1st years) 1/2 to 1 cup (depending on trunk diameter) of Dr Earth 5-5-2 the start of April. I also read that I should limit the nitrogen unless the vine is low vigor, whereas the last several years I just gave all mature vines a shot of the 5-5-2 every 2 months during the growing season as the directions on the bag say, which once again I found to be counter to conventional wisdom. So my plan now is to watch the vines and only give them more fertilizer as needed, although given some of the stunted shoots on a few of the Zinfandel vines maybe that time is now.

Yeah that makes a lot of sense, too many factors just overworked the vine and killed it. For reference, here's how the row of Zinfandel looked at the end Labor Day weekend 2020. The closest to the camera is still alive and producing, but it does have stunted shoots and several buds that never broke this year. The second from the camera is the one that was fully dead by spring 2021. I harvested everything that weekend prematurely because the heat basically destroyed the vines and much of the grapes. Here's a picture of what it did to some of the grapes that we're a nice dark purple just days before.


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## vtoddw (Apr 29, 2022)

balatonwine said:


> This and other post comments are interesting, but sadly provide little value. Mainly because this is one plant. Thus one data point. And little to nothing can be extrapolated from one data point.
> 
> For example,
> 
> ...





Given your experiment that certainly implies that the Bermuda grass is a problem, but not the singular cause. Good to know and I'm glad you clarified that especially for anyone reading this thread as it's important that writing this off as a Bermuda Grass problem is not how we left it given that per your experience it's likely not the only factor. 

In hind sight, I think the weak roots is likely a big issue for me, as I really have been progressively learning over the years from books and google searches, but I've never taken the time to seek assistance until now. When it comes to the information I've read, it's often incomplete leaving gaps or it's too circumstantial. For example, I've read that vines need deep watering and should dry out, so should only be watered once a week. Then in practice, as indicated in my prior post, that was not sufficient for every day. I've also read that once a vine is established, it doesn't need any water at all as it's roots will get it from ground water, but based on past experiences I'm fairly confident that if I turn off my irrigation for the next two weeks all of my 6 and 7 year old vines will die. It really is hard to know who and what to believe, because the fast is it all depends on a lot of environmental factors. 

So the way I imagine that translates to weak roots is that I've been underwatering the vines for years and possibly not giving them the right nutrients (I know that for sure with the Zinfandel at least). Also in regards to the weeds, I do use a cultivator in the late winter around pruning time, although I'm admittedly timid with it as I don't want to go to deep and damage the vine roots, but maybe I'm too timid as the vine roots do tend to grow downward as I've discovered from the one I pulled.

The other piece of info of note here is that when you look at the 3 vines in the same row on either side of the one I pulled, they are (for now) doing great. This vine I dug up has always been low vigor but was planted the same year (spring of 2018) as the other 3, all from the same nursery. Come to think of it there is another vine in that row which also has had consistently low vigor, shown in picture 154114 here.


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## vtoddw (Apr 29, 2022)

balatonwine said:


> I hope you did not dig up your vine simply due to fears of Phyloxera that others may have made here. Because Phyloxera is endemic to the USA and exists pretty much anywhere there are vines. If you have Phyloxera on one vine you have them on all of your vines. Soil types and other mitigating factors allow some areas to remain functionally Phyloxera "free" structurally, and allow native rooted vines to grow mostly healthy (even if some succumb to the louse). So removing and killing one vine out of fear it will "infect others" from Phyloxera will have mostly zero benefit for your vineyard. If the vine was sick due to other issues, especially virus or bacterial disease, then removing it may have been a good idea. But to know that, for certain, you need to send the plant to a lab for analysis. To say otherwise, no amount of forum "_experts_" pontificating what _*they*_ think is the problem, or what you should do, based on their pontificates, is not worth a brass farthing.... or the Yankee equivalent: is not worth a damn.... (what is appropriate is depending on which side of the pond one is, and what is the level of censor at forums such as this as to what is appropriate language...  ).



Well yes and no, the feedback I received did encourage me to pull the vine but I came to the conclusion on my own based on the cost vs benefit of keeping it or removing it. From what I've been reading you do have a point that it was likely too late if it was Phyloxera, but I also needed to know if it was something else that posed an avoidable risk to the rest of the vines. Some of these vines are actually 6 and 7 years old, so I'd rather not lose them too for the sake of one low-vigor vine that may or may not die by the end of the summer anyway. I have yet to take the step of actually sending my soil or vines to a lab for analysis, but if things continue to worsen this season then maybe that's my next move. In the grand scheme of things, I'll still make wine this year by buying grapes from local growers, but I've put a lot of time, money and effort into my little vineyard so ideally I'd like to get a meaningful return out of it.


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## Fox Squirrel Vin (Apr 30, 2022)

vtoddw said:


> Thank you again for your invaluable feedback, I'm learning a ton here!
> 
> Fortunately 115 is not the average, it's usually between 90 and 104 here during any given summer day, but coincidentally the last two Labor Days were record breakers, not exactly trending in a good direction.
> 
> ...


When it starts warming up for you, try keeping the soil damp at all times and do light cultivation where you think the roots end. That will help keep the soil soft and the phosphate will encourage growth. It's ok if you cut some of the small roots in tilling because that encourages more root growth.

It's really not true that the soil should dry or it isn't good for the plant, I live in Florida and all growing season when the plants have fruit, my soil is moist and in August the water table is 18 inches below the surface and there are periods where it is saturated and they do fine. A lot of grape regions in France have substantial rains during the fruit ripening stage. When I water during a dry spell I have my drip set to deliver 2 gallons every 2 days. You don't need to increase how much water you are giving them when it's hot, you need to increase the frequency. 4 gallons accomplishes the same as two because that excess water just seeps deep into the soil where there are no roots and isn't available to the plant. 

If I am going to give them nitrogen, I do it in spring at bud formation, If the plant looks light on buds or they seem to be growing slow I give them nitrogen because I want good, excessive fruit bearing shoots that I can prune back after I see the quality of the fruit bunches/clusters that form on them rather than shoots with no fruit. This method lets me choose the best vines with the best fruit and I can prune the clusters that are sparse and poor quality. All they do is increase the demand on the plant and steal from the clusters that I want to perform the best. A good 10-10-10 fertilizer is ideal at this stage. Get your fertilizer from a good garden center, fertilizer from big box stores is usually crap. I will also do a micro nutrient foliar spray just after fruit set, I use a product the citrus growers use, this just helps to make sure the plans have everything they need to get off to a good start before the heat of summer sets in. 

You look like you are in an arid climate so I'm not sure what your fungus pressure is like but I spray 7 different fugicide groups alternating every 14 days. I have no choice, It's Florida. I spend thousands of dollars on fungicides every year, not just on the grapes but all the crops. The fungus pressure here is intense.


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## vtoddw (May 1, 2022)

Fox Squirrel Vin said:


> When it starts warming up for you, try keeping the soil damp at all times and do light cultivation where you think the roots end. That will help keep the soil soft and the phosphate will encourage growth. It's ok if you cut some of the small roots in tilling because that encourages more root growth.
> 
> It's really not true that the soil should dry or it isn't good for the plant, I live in Florida and all growing season when the plants have fruit, my soil is moist and in August the water table is 18 inches below the surface and there are periods where it is saturated and they do fine. A lot of grape regions in France have substantial rains during the fruit ripening stage. When I water during a dry spell I have my drip set to deliver 2 gallons every 2 days. You don't need to increase how much water you are giving them when it's hot, you need to increase the frequency. 4 gallons accomplishes the same as two because that excess water just seeps deep into the soil where there are no roots and isn't available to the plant.
> 
> ...



Yeah it's very arid here, we don't get much rain at all so irrigation is always necessary. Right now my watering is every Monday and Friday so I really never let them dry out much, except maybe by Thursday, but that makes sense that doubling the water per day doesn't necessarily mean the plant can actually absorb it all before it dissipates in the soil, so maybe I'll try out every 2 days when it starts getting hotter and watch the leaves for signs of overwatering. I'll also take you advise and do some extra cultivation, that's a good idea. The fertilizer I've been using it from Armstrong nursery, so I'm not sure where it lays on the spectrum, but it's definitely not Home depot / Lowes so maybe it's decent stuff. But again it's 5-5-2 fruit / vine fertilizer, not really specified for grape growing so I'll seek out some 10-10-10 and give that a shot. I also only gave the Zinfandel row the extra Potassium, but I'm thinkin maybe I should have done that for the whole vineyard as I imagine they are all depleting their nutrients at a fairly relative rate.

I actually just went up there today and cluster thinned everything down to the one cluster closest to the basil per spur because most of the grapes are flowering right now and I've read that you want to do your cluster thinning before fruit set to get the best quality (no clue if that's true). I also broke off several of the shoots that were stunted and didn't offer a good bud position for next year or that were vigorous but blocked the sunlight on the clusters excessively. 

In terms of fungus, even as hot and dry as it is out here, I've had Powdery Mildew on a 2 of my oldest vines the last 2 years, plus what I believe is Grapevine Leaf Rust on some of the older one's as well but I'm not 100% sure about the latter. My planned spraying schedule is using "Bonide Sulfur Fungicide Dust" every 2 weeks for the first 10 weeks of the growing season. That said, I've skipped the last spray (which would have been last weekend) because I released a bunch of Green Lacewing larva on the grapes in order to eat any of the possible sharpshooter eggs last Wednesday, so I didn't want to kill them with the Sulfur just incase they are sensitive to it. I also spray the fungicide at night because it's just way too hot during the day and as I understand it will damage the plants if sprayed during heat above 85F, not to mention it's easier on me as well, but I really need to get back out there and spray next week as I'm definitely overdue.

I was using an oil based fungicide in prior years but purchased the Sulfur Dust last year in response to the fact that although the Powdery mildew stayed in check, I started seeing what appears to be grape leaf rust show up, which the oil based fungicide did not say it was effective against.

Here's a pic of what I believe is likely Grape Leaf Rust.


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## Fox Squirrel Vin (May 1, 2022)

From today


vtoddw said:


> Yeah it's very arid here, we don't get much rain at all so irrigation is always necessary. Right now my watering is every Monday and Friday so I really never let them dry out much, except maybe by Thursday, but that makes sense that doubling the water per day doesn't necessarily mean the plant can actually absorb it all before it dissipates in the soil, so maybe I'll try out every 2 days when it starts getting hotter and watch the leaves for signs of overwatering. I'll also take you advise and do some extra cultivation, that's a good idea. The fertilizer I've been using it from Armstrong nursery, so I'm not sure where it lays on the spectrum, but it's definitely not Home depot / Lowes so maybe it's decent stuff. But again it's 5-5-2 fruit / vine fertilizer, not really specified for grape growing so I'll seek out some 10-10-10 and give that a shot. I also only gave the Zinfandel row the extra Potassium, but I'm thinkin maybe I should have done that for the whole vineyard as I imagine they are all depleting their nutrients at a fairly relative rate.
> 
> I actually just went up there today and cluster thinned everything down to the one cluster closest to the basil per spur because most of the grapes are flowering right now and I've read that you want to do your cluster thinning before fruit set to get the best quality (no clue if that's true). I also broke off several of the shoots that were stunted and didn't offer a good bud position for next year or that were vigorous but blocked the sunlight on the clusters excessively.
> 
> ...


Don't use the oils, they harm the plants at temps above 85 degrees, sulfur can also cause injury at temps over 85.









Sulfur Injury on Grapevines - News


Rick Dunst, Viticulturist, Double A Vineyards, Inc. Powdery mildew (PM) is an important vineyard disease worldwide. As pointed out by Cornell University grape plant pathologist Wayne Wilcox, Eastern North America is the origin of powdery mildew, and we cannot grow grapes here without...




doubleavineyards.com


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## balatonwine (May 1, 2022)

Fox Squirrel Vin said:


> Trying to rejuvenate a vine that has issues when it is so much easier to replace it with a healthy one is not worth the effort, it wasn't a 20 year old plant. He can make plenty of new plants from the plants he has now without worrying about introducing anything from a commercial supplier.



I agree. But....



Fox Squirrel Vin said:


> Removing the vine allows you to see into it's past and why it died and what you can improve on.



This is one data point. Nearly impossible to learn much from one event.



Fox Squirrel Vin said:


> He learned 2 things, the roots were less than sufficient so he needs to focus on methods to improve the root system, and, there looks to be some nematode damage.



I do agree there are indicators to improve the root system, but is far more complicated than only "2 things". As I already stated, presence of nematode damage is inconclusive. Such damage maybe causal causing the vine's decline, or relative and simply a symptom of damage to a weekend vine. To confirm one or the other, we need to ask the OP to pull up many healthy vines and compare nematode loads. Healthy vines can actually sustain quite a lot of root damage. So we would need to compare. I doubt he will do that. Even so... it is still an issue of maybe confusing correlation and cause and effect.

And do not get me started on my opinions of the issues root quality of irrigated versus not irrigated vineyards.....




Fox Squirrel Vin said:


> Improving 2 issues when you may have 5 is a 40% improvement



Where did you pull those numbers from? 40%???

It sounds like the saying, 90% of comments here are false. And the rest are simply wrong. (i.e. if you use %, be prepared to quote authoritarian sources, or willing to admit your % is made up....)

*Note*: Made a few edits to my post. The one at 17:45 my time (CET) is my last edit and the one to reply to.


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## vtoddw (May 1, 2022)

Fox Squirrel Vin said:


> From today
> 
> Don't use the oils, they harm the plants at temps above 85 degrees, sulfur can also cause injury at temps over 85.
> 
> ...



Great article, nice to see an explanation as to why the bag says not to apply above 85F. Yeah I've stopped using the oil because it said it was only effective against powdery mildew, hence the grape leaf rust. It was effective on powdery mildew as a corrective measure, rather than just preventive, which was nice, but as long as I'm staying on top of the Sulphur spraying I should be good.


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