Knowledgebase
What’s on my grapevine #878903
Asked July 26, 2024, 1:06 PM EDT
Dakota County Minnesota
Expert Response
Thanks for the question.
I think that the structure on your grape vine is a crown gall. This is an enlargement attributable to a bacterial infection by Agrobacterium vitis. However, I do have some reservations as to the accuracy of my diagnosis. If I am correct, this is a serious condition for which control is difficult. Because of my uncertainty and the possible severity to the vine if I am correct, I believe that you need to have a licensed, professional arborist make an on-site inspection and assessment. Here is some more information about these and other points:
https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional
https://grapes.extension.org/crown-gall-of-grapes/
https://www.canr.msu.edu/grapes/uploads/files/GrapeFacts-CrownGall-web.pdf
https://ecommons.cornell.edu/server/api/core/bitstreams/8a294d77-1eb5-4260-ab6d-b452da4782a1/content
Again, I apologize for the uncertainty in my answer. Consultation between you and arborist should be done. Thanks for using our forum