Hello, novice grower and winemaker here, with Marquette vines in their third year in Ohio. Did not spray fungicide, being a tree-hugging wannabe, and no signs of disease first 2 years. Black rot got about 1/2 my 3rd year crop, but I still have a lot left that look nice. Next year the spray tanks will be primed and ready. It was actually a pretty full crop for year 3, more than I expected, anyway, so I guess I'm prob. still where I thought I would be in terms of yield this year. 18 vines. Bought some "practice" Marquette grapes last fall from Michigan, and the carboy is about ready to bottle, and I'm optimistic about the potential! I do have one vine showing colors, but when I looked closely, I see the vine is stressed. Funny little spongy "fingers" coming out of slightly swollen area around the base, picture included. Crown gall?View attachment 49839 View attachment 49840
Hmmm, well Marquette is winter hardy, so it probably isn't winter damage. As for galling, it looks like an interesting abnormality. If it's the crown gall bacterium, then I don't know what to tell you. If you want to stay organic, the try Serenade and Neem oil. Use often and regularly to help your vines fight the fungi. They are not as effective as some of the chemical fungicides, but they are considered safe . I've read that people drink Neem oil for it's health benefits(not me cause it stinks), so it can't be that dangerous. If you start with a dormant oil early, that will help too. I'd contact your local extension office to see if they can direct you to someone that could evaluate the issue. I'm not sure what part of Ohio you are in, but OSU has a research center at Piketon with a viticulturist handy.