Grapevine leaves wilting... ideas for treatment?

[jgroebuck]

Hi,

I bought a grapevine last month and the leaves are beginning to wilt and become brittle especially around the leaf blades. There are some discoloured patches on the leaves and they lack any vitality.

I had a look around the internet for a diagnosis but I cannot be sure what it is. The disease I think it may have is Bois Noir caused by phytoplasmas, however I could be wrong and unfortunatley there is no evident treatment for this.

If the viewers of this post have any idea what it is and how I could treat this I would greatly appreciate any info. Pictures of my grapevine are shown below.

Thanks!

[FB.]

Looks like irregular water supply.
This year has been incredibly dry - even the weeds are dying round here.

[FB.]

If it's not irregular water supply, then the other dry-weather-enemy may be the cause; powdery mildew.
Good water and nutrition help reduce powdery mildew, while drought-stressed or starved plants are very prone to mildew.
Last year, we had a low-rainfall growing season and my grape almost died from drought and mildew. It lost all fruit and leaves and I thought it was dead. During the winter, I scraped off some bark and found it was still alve in places, so I cut it back to live stems and it is growing happily again.
But drought and poor soil is something I have to live with almost every season, so after a couple of years of establishment, the plants must fend for themselves and they either live or die.

[jgroebuck]

Hi FB,

Thanks very much for your reply, it was very informative.

However, it may not be irregular water supply. I water my grape every morning and feed it miracle grow and bone meal. I have lots of other plants and veg around my garden. A tomato plant withered and died but I think it was because of the cold start to the summer. Do you think the wind could have transferred harmful spores from other plants to my grapevine?

I will continue to water and nourish my plant. Thanks again FB.

[FB.]

Most diseases are specific to a particular plant family, so I doubt that your grape has caught anything from your otehr plants.
But maybe someone nearby has a neglected grape that has become chronically infected with diseases - and those diseases get blown by the wind.
I'm frustrated at the moment because the weather has given so little rain for months and there are several neglected old apple trees nearby that are thick with powdery mildew - and it is spreading onto mine in the last week or two (although mine are fairly resistant, but under extreme disease attack, even resistant varieties will succumb).

[jgroebuck]

Ah ok. That comforts me a bit. I was worried it may have been a terrible disease. I don't think any of my neighbours have grapevines. Like you said I will water it regularly and hope for the best.

Sorry to hear about your apple trees. It has been very dry recently, even in Scotland where I live.

Thanks

[jpdw]

Out of interest "how much" water does a vine require? (roughly -- I'm not expecting X/litres per day). We've got 4 vines - 3 in pots and 1 we planted out from a pot earlier this year -- I think all 4 suffered from underwatering last year, but I dont want to overdo it this year.

[FB.]

Anything in pots needs a lot of water, since pots drain and quickly dry out.

A grapevine planted in the ground should eventually root itself very deep and after that, it won't need watering unless there is a severe drought. Grapes are renowned for their deep roots that just keeping growing straight down, until they hit the water table.
My Black Hamburg grows in a poor/shallow/dry spot where even the weeds can't establish.