grape leaves - Ask Extension
Hi,
I have a few grape vines up on arched wire trellises.
Many of the leaves of my Bluebell grapes have splotches (not spots and not powdery) of...
Knowledgebase
grape leaves #876728
Asked July 10, 2024, 5:16 PM EDT
Hi,
I have a few grape vines up on arched wire trellises.
Many of the leaves of my Bluebell grapes have splotches (not spots and not powdery) of light brown on the underside of the leaves and some morph so that the brown appears on the top of the leaves also.
We have had considerable rain in Rochester and it has been quite humid. I have been alternately spraying the grapes with Captan and Immunox for fungus.
The grape bunches and stems show no browning or deformity.
I have a St.Theresa grape adjacent to the Bluebell grape that does not appear to be affected by this browning of the leaves.
Any information would be appreciated. I will include a couple of pictures for you to view.
Greg
Olmsted County Minnesota
Expert Response
The following publication addresses your question:
https://extension.umd.edu/resource/red-leaves-vineyard-diagnosis-and-management/
We can't determine whether one of the causes noted in the publication is affecting your plant by viewing the photos.
For a reliable diagnosis, send samples of affected leaves to the University of Minnesota Plant Disease Clinic.
https://pdc.umn.edu/
https://extension.umd.edu/resource/red-leaves-vineyard-diagnosis-and-management/
We can't determine whether one of the causes noted in the publication is affecting your plant by viewing the photos.
For a reliable diagnosis, send samples of affected leaves to the University of Minnesota Plant Disease Clinic.
https://pdc.umn.edu/
