See this link below

Here is a link that might be useful: Glenora

I grow Glenora here in the Idaho high desert. I have not had any problems with black rot or mildew on Glenora, in fact, I do not even spray them (except for dormant). Of the varieties I grow, it is one of the easiest. I just keep them trellised, pruned, and open up the canopy, Glenora is VERY vigorous.

To me the taste is very good, but for some reason, mine are quite tannic. They give my mouth a "dry" sensation if I eat too many. The tannins do decrease and sugar increases the longer I let them hang - but go too long and the berries get soft. We eat them over a long time period as they can hang for several weeks before getting soft. They reach 26 or so brix for me before softening, which is quite high for a table grape. Because of the sugar and tannin content, I've been tempted to try fermenting some... but to get enough to make it worth while I'd have to use my whole crop (no eating for a year).

Even though they are "seedless" I do get some seeds, but they are small and not really a problem.