Hi,
Is this Botrytis Bunch Rot? How do I prevent it? Is it too late for this season? Any organic option? Thank you
MUSCAT OTTONEL on 101-14 rootstock planted last year (Zone 7b, New York metro)
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Yes, that looks like rot. Like most other grapevine fungus, once it appears it is too late for the infected grapes. However, you should destroy the rotten grapes. Then spraying with Captan will help protect the uninfected grapes. Don’t allow mummified grapes to over winter.
Proper pruning in late winter will open the grapevine canopy and allow better sunlight penetration and improve air circulation while also aiding in spray penetration and coverage of fruit. At bud break spray with sulfur (lime-sulfur if you can find it) and then with Captan in subsequent sprays.
Here is the spray guide that I generally follow for my stuff:
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I have a grape leaf curl situation:
Need help - what is cause and how to treat leaf curl on fredonia grape leaves-young vines.
Almost all leaves are infected in one vine and half on another vine
No bugs insects, aphids visible.
Several others ok.
thanks
That’s probably herbicide injury. Grapes are very sensitive to some herbicides, like 2,4-D types, and it shows up as small deformed leaves. The herbicide can blow in from a long distance but more likely close by. Did you use any herbicide?
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I did use Sevin" in the area, and Ortho fruit tree spray nearby.
Very interesting.
Will grape recover?
Just from the looks of it I’d say yes. But it can take a year or two if severe. Yours doesn’t look too severe.
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Thanks Steve!!
If you spray before the clusters close up
you may save some fruit
but once the tight clusters close it’s too late.