Weez wrote "Are you sure about the black spot? I was hoping I beat it this
year! I've
> been using fruit plus (ferbam and something else) every 7-10 days. The
vines
> are Marechal Foch. Weather has been cool and humidity has been staying
> mostly under 50%, rain once or twice a week mostly at night...
> Louise)"

Louise - I'm not sure it's black rot but it sure looks like what I have in
the vineyard. The other grape growers in our Cellarmaster club say it's
black rot. Also, it looks like the black rot picture #21 in the Compendium
of Grape Diseases. And from the 2004 Missouri Commercial Grape Pest
Management Guide..."Leaves: tan spots develop with small black pustules,
concentric with the lesion margin..." Here, in the Kansas City area, we've
had lots of rain and black rot is showing up in vineyards. I have some in
most of the varieties I grow and I follow a rigorous spray program.

The Missouri literature says ferbam will not prevent disease development if
applied after the fungus has infected the fruit or leaves. If you don't
have any grape infection yet sounds like your spray program is pretty
effective even though you see some leaf involvement.

I use Nova in combination with Mancozeb and will shift to Nova/Captan
starting this week. You might consider Nova if you problem gets worse.
Nova offers some protection that Ferban, Mancozeb and Captan can not offer.
Also, it is said to have some curative action if applied within three days
of infection.

I used to grow Leon Millot (cousin of Foch) and always had a good crop so
the small amount of black rot you have probably won't kill your crop. Your
grapes should turn red any time now and then black rot will no longer be a
propblem.

Bill Frazier
Olathe, Kansas USA