Bill, my experience is usually the same as yours. However, this year just the opposite is true. My Chambourcin and Chancellor are doing great but the berries (not leaves) of the vinifera got hit pretty hard. This year I have been using JMS oil. I don't know if that is the difference or not. This year in Central Maryland has been the "Perfect Storm" for fungal attack. We had 13 inches of rain in about 5 days (right after fruit set) and it was impossible to keep a spray down without washing off. Usually this time of year my Chambourcin are getting ragged with a speckle on the leaves and some defoliation - not so this year. It is good that I will at least have some good hybrid grapes but Chambourcin is not my favorite. I know that with the right amount of oak and several years of aging it does come around though.
"William Frazier" > wrote in message ...
wrote "I have tried to grow organically. It worked
extremely well on
chamboucin and not so well on vinifera."

Bob - I don't attempt to grow grapes here in the Kansas City area without a
multiple fungicide spray schedule. Dithane/Nova alternated with
Dithane/Quintec early season. Sub. Captan later. Insecticide infrequently.
Your comment about Chambourcin is interesting. I have more problem with
Chambourcin and Vignoles than other grapes in the vineyard. C. Franc, C.
Sauvignon and Chardonnay leaves show no sign of disease at this time while
the leaves of the two hybrids look pretty rough. Where do you grow your
Chambourcin? BTW, Baco Noir and NY73 started veraison this week.

Bill Frazier
Olathe, Kansas USA