Controlling Black Rot in Concord grapes

Asked July 30, 2018, 8:29 AM EDT

I think my Concord grapes have black rot. It doesn't appear to be widespread. I have 4 vines about 10 years old with about 50 ft. of vines loaded. From what I could find out I think it's too late for fungicide. If not, what should I use? If so, what I do? Cut everything back and dispose of it? Thank you.

Midland County Michigan

3 Responses

Sorry this took so long. I had the answer typed up yesterday and my machine hiccuped and I lost the answer but have to leave for a grower appointment.
Yes that is black rot of grapes. The Concord berries are very susceptible after bloom for 4 to 6 weeks. Now the period of berry susceptibility is over so the disease should not spread any further this season. You do not need to cut out and destroy the diseased berries. They will dry up into hard black raisins.
Next year you need to apply fungicides after bloom on a 7 to 10 day schedule to protect the grapes. Start right after bloom and apply the fungicides more often if it is rainy and wet and less often if the weather is dry.
When you prune the grapes in the early spring be sure that all the old mummies from this years infection or removed from the vine.
Here is a link to more information.

First, thank you! So, it looks like I can still make some jam and juice which makes me happy.
Secondly, when you have time, can you advise on specific fungicide and where I can find good info on how to prune Concord grapes. Thanks, again. This AAE prorgram is awesome.

Please send me an email and I will send you that information