[goodier]

Hello, I have been growing a grape vine(black hamburg) in my green house for five years. It is rooted through an open bottom tub into the soil. Last year the leaves and grapes became covered in a grey powdery mildew. I put this down high humidity through por ventilation. I cut and burnt all the shoots leaves and grapes. Was meticulus with the winter cleaning, Jeyes fluid etc. Have ventilated properly this year but the mildew has reapeared.
Is there a safe fungicide I can spray, bearing in mind i want to eat the grapes. How do i prevent a reacurrance?

Many thanks

John

[Biscombe]

I spray my vines here in Spain with organic copper sulphate once every 2 weeks when the grapes are pea size.

[goodier]

Many thanks, will follow suit next season , for the moment i have cut off all the grapes then sprayed the leaves with a systemic fungicde. Hoping that this way some curative action will take place during the rest of this season.

John

[Biscombe]

If you get can't get hold of copper sulphate let me know and I'll send you some xx

[goodier]

That's so kind. Many thanks

John

PS we are frequent visitors to Spain are your grapes at all close to Calpe?

[NigelB]

Sorry to bring an old topic up, but it seems to be the right place to ask if anyone can explain, (In simple, easy to understand figures  ) the dilution rates of Copper Sulphate for spraying on grapes?
I bought some (Half-a-flippin Kilo  ) on-line, but although it comes with more safety warnings than you could poke a very pokey stick at, no instructions for agricultural use...
Can anyone help? I have a 1.5Litre spray-gun and would like to mix it in that, if that helps...  :blink:... probably not.

Thanks!

Nig

[tode]

Normally its Bordeux mixture thats used in French vineyards (& on tomatoes, etc). The application rate for vines is 20 gm/litre.
Im not at all sure about using straight copper sulphate: I would imagine that its more acidic. 
The Bordeaux mixture is made by mixing slaked quicklime with copper sulphate (about half and half, I think) - you should be able to find the recipe on the web.