Sick grapevine. What's it suffering from and what's the cure?

[bacoms]

Hi, Am a complete newb to growing grapes. Planted 2 vines in the spring on a trellis with a view to using them to cover a pergola. All seemed well until I came back recently from a week away. One seemed decidedly sick.

The following photos show the front and back of an affected leaf.

;

Anyone know what's causing it and how best to cure it.

[rustylady]

Sorry, don't know what's causing it but I would just pick off and burn the affected leaves. It's getting on for Autumn now so you can expect to lose the leaves anyway.

[bacoms]

Sounds reasonable. I'll do as you suggest and see what happens.

Thanks.

[roitelet]

Looks like some sort of mildew to me. Mine have it too, sorry I don't know a treatment. I have just taken off the affected leaves and the grapes seem OK.

[bacoms]

It certainly looks like mildew. When removing the affected leaves I noticed that some of the stems were also covered in a white powder. However, unlike the leaves where whatever it is seems to have infected the fabric of the leaf, the powder on the stems could simply be wiped off.

Good luck with the harvest.