Strange growth on Marquette vine

[Cynewulf]

I found this on one of my Marquette vines today. Does anybody recognize this and know what it is?

 

[VinesnBines]

Someone else on this site has something similar and said crown gall. Contact Mizuho Nita at the VA Tech Ag Research Center. He is the expert on plant pathology.

 

[treesaver]

If you do contact that person, please post up what he says. I did some research on crown gall and found they mentioned an areal manfistation, and I believe that is what we have. The vine that had the growth pictured in my thread, is about twelve years old with no sign of crown gall on the trunk. I took another off of a young vine yesterday that had a simalar growth, and that vine is only about three or four years old, and once again, no sign of CG on the trunk. The vines I have found them on are frontenac, and have never seen them in the past.

 

[Cynewulf]

Someone else on this site has something similar and said crown gall. Contact Mizuho Nita at the VA Tech Ag Research Center. He is the expert on plant pathology.

That’s a good idea. I follow Mizuho’s grape pathology blog and have been meaning to reach out to him with some other questions so this will be a good excuse to finally do it.

 

[VinesnBines]

Please post the answers. Crown gall is troubling.

 

[Cynewulf]

I’ve written to Mizuho and will let y’all know what he says if/when he writes back. I’m optimistic that it’s not crown gall based on pictures I’ve seen and that it’s showing up on a shoot when it’s 90 degrees here in Virginia but I have no idea what else it might be so we’ll see.

 

[treesaver]

Only difference in our year, is that we have had a cool spring and when it turned hot this summer, it has been interspersed with cool and rainey spells. I'm in Ks, and it is usually 100+ this time of the year, and we just had a week of low humidity and 75 degree days, very unusual for this time of year!

Thank you for the replys, No one wanted to comment on my thread!

 

[Cynewulf]

I just heard back from Mizuho and he nailed it (also a huge relief):

It looks like grape tumid gallmaker. Often time, it is not a big deal. I believe it becomes an issue when the infestation happens earlier in the season.

https://www.virginiafruit.ento.vt.edu/grapegalls.html
https://psuwineandgrapes.wordpress.com/tag/grape-tumid-gallmaker/
Best,
Mizuho

I also looked up this interesting article: Grape tumid gall maker- curiosity and management. Before he responded I cut open a couple of the galls and saw what looked kind of like seeds. Now I realize they were the maggots. Now I can go back to worrying about a surprise downy mildew outbreak on my Cabernet Franc!

 

[VinesnBines]

Great news! Thanks. I have a little downy mildew on my hybrids. Not much so hope my spray helps.

 

[treesaver]

Well, that is not anything like what is in my frontenacs. See the pic in my post, "What the hell is this?" Does not look anything like the pics in the attatchment. Also, they state it is in the NE section of the country. Crap!

 

[Cynewulf]

Perhaps not the two links that Mizuho shared, but I’d say your photo looks a lot like the first photo in the third link, this one: Grape tumid gall maker- curiosity and management.

 

[treesaver]

Thanks for that link, Cynewulf. That is indeed what mine look like, and makes me feel much better! I appreciate the help on the matter, thank you!