Grapevine trouble with Phomopsis disease

[Tril]

I just have 8 grapevines growing on a Arbor of a few different varieties. And I have had trouble with Phomopsis disease every year. Always black/brown lesions on the cane and shoots and leafs themselves infected.

I been using Neem Oil, but it does not seem to help much or else I am not using it often enough. I spray every 14 days 1oz per gallon of water, and just now started to try 7 days cycle.

I looked at several other sprays that supposedly work better for this, but at $200 a bottle for Abound that's to much just for a backyard grape operation.

Anyone have some ideas what I can use that might work that's affordable

Been trying to grow Grapes for 5 years and never once have I had a cluster grow, just a few grapes here and there cause usually some disease kills them, like Blackrot or whatever.

2 years ago something hit the vines hard and I had to cut them back to a few feet off the ground and let them grow back. So this is second year wood again and I finally have a bunch of clusters for first time forming and would like to see grapes before I die

[veggiechicken]

Hello and welcome.
It would help us if you could tell us where you live? I take it its not the UK where the majority of members of this forum are based.

[Tril]

Hello and welcome.
It would help us if you could tell us where you live? I take it its not the UK where the majority of members of this forum are based.

I live in PA.

lol, sorry I thought I said it in my post.

[Tril]

Hello and welcome.
It would help us if you could tell us where you live? I take it its not the UK where the majority of members of this forum are based.

Did not realize this is a UK site

[Tril]

If you know of a good forum in USA let me know please, maybe that would be better for me.

[veggiechicken]

We do have members in other countries but I couldn't find much advice on Phomopsis on UK sites so I thought it might not be a common problem here. We're not exactly noted for our wines

[Snoop Puss]

It's an everywhere site, though most members are in the UK.

I've never heard of Phomopsis. I've had a look about on the web, which I guess you've done too. It sounds like Phomopsis is extremely difficult to prevent and impossible to cure. There are lots of university sites in the States that recommend a few chemical treatments, but I've not seem neem mentioned. What do other people near you do?

[Jay-ell]

Hi Tril and welcome to the vine.

I havent heard of it before but a quick google brought up mentions of Lime Sulphur
UC IPM: UC Management Guidelines for Phomopsis Cane and Leafspot on Grape

Potassium Bicarbonate is often used to control fungal infections, as is sodium bicarbonate to a lesser extent. This product claims to tackle Phomopsis and appears to be potassium bicarbonate based.
What is GreenCure?

Of course as with any fungicide you'd need to check up on them and research any potential toxicity.

P.S. Everyone is welcome here no matter where you live - it's just that the majority (BUT NOT ALL) members are in the UK.

[Tril]

Thanks for the reply's.

I think I found what I need here in the USA, it's called Dithane and should take care of what I need, won't cure it, but stops it from spreading.

Have to put it on early next year so it does not take hold again according to what I read and yes the Sulfur thing might work to, this Dithane seems like it's easier to use.

[Deltawhiskey]

One of my books recommends a 2% tar oil winter wash which the author says will sort out many of the surface infections. One of the problems in the UK is that there are, according to the RHS, no fungicides available to the gardener for grape vines. You can buy small spray bottles but they are far too expensive to spray vines. I planted 60 vines this year and used only disease resistant hybrids. I am hoping that with regular sprays of seaweed extract to toughen the leaves and feed the vine with micronutrients the nasties will be kept at bay. I have heard that milk at 60% in water can kill certain fungus and is being trailed in New Zealand by organic growers.

David

[nickdub]

One old time fungicide is Bordeaux mixture, which is/was made from of copper sulphate crystals and slaked lime. Some of the gardening books of 50+ years ago used to describe how to make it up fresh yourself.

None too sure if you can still buy it in the UK - or what the legal position would be if you made it yourself. I have used it in the past, but would probably be too lazy to bother now. If you do mix it on your own, you need to use plastic or ceramic containers - it'll bugger up any galvanised ones.

[Deltawhiskey]

One of the drawbacks with Bordeaux mixture is that it delays ripening some say as much as 10 days per application. In our climate that can be a problem. This is obviously not a problem in warmer climates. The other problem is that the copper can build to a toxic level in the soil.

David

[nickdub]

Everyone has to make up their own mind when they are growing stuff re chemicals etc. Personally I wouldn't use it on fruit after the flowering stage, but I'd have no objection in principle to using it before that, on leaves or stems say.

I've no experience of ripening grapes in the open, so I can't comment on that (the few I grow are all under cover).

I suppose if its worth it to you, you could do a trial on just one vine next year to see what the effects are. My only observation from trying it on a peach tree yonks ago, was that you need to get the spray on long before any symptoms of fungus, ie as soon as the leaves started growing. I believe that if you wanted to limit the drip and splatter of spraying, you could use a brush to apply the mixture to the vine rods.