Kitchen Garden Forum

I haven't had time to pop by for a while, but I have a problem with my grapevine.

back story:
the grapevine is over 20 years old, as it was at the allotment when we took it on in 1993. it grows against a south-east facing wall, and 2 years ago, we constructed a pergola to train it on. we have never really bothered with it, as it always gets powdery mildew, so we just chop it and ignore it. But I decided a few years ago to try and get it to fruit. this is the 3rd year of pruning and it looks fabulous.

so, this year, it has produce over 30 lovely bunches of teeny grapes that were growing and looking good. I was cutting back all extra growth to keep the air moving and there was no PM visible on the foliage. until a couple of weeks ago, when all but one bunch of fruits started to show signs of PM. they are now mummified, hard and cracked and revolting.

there is one bunch which seems ok which is turning a nice shade of metallic pink/purple.

what can I do for next year? I have heard of copper soap. does that still exist?
I'd really like to get a crop, as I make wine, and am determined to make some from this vine!

Wasn't Bordeaux mixture discovered to protect against this very ailment of the grape?

Cheers, Tony.

i think bordeaux is being withdrawn pretty soon, might try and get some before they remove it from the shelves.

I think it's just been one of those years. I've seen more fungal diseases than ever before so I'd be inclined to hope for better things next year. If you're a belt and braces man you could opt for chemical weapons just in case.

The only legal remedies tor potato blight are now copper based, do could probably substitute.

I believe the way these copper based products work is by the solution residue or the powder left on the plant preventing the mould spores from germinating. Hence the need for reapplication after rain.

Repeated use in the wine industry, possibly over-application, made soil copper toxic.