On Sat, 20 Aug 2011, Nick Maclaren wrote:

Thirdly, removing blighted material is of marginal benefit, anyway,
as it overwinters in a large number of common plants and weeds, and
transfers by the wind. Yes, it's worth doing, but it won't make
much difference; spraying with Bordeaux mixture at the right time
will.

Humph! I've just suffered a total loss of my tomato crop as a result of
two days very humid weather at the beginning of this week. At least, it
took the humid weather to bring it out. First time I'd grown tomatoes
for many years and someone gave me the plants otherwise I wouldn't have
bothered. They came on beautifully and, a week ago they were looking
fine. Then came the humid weather and within a day they were looking
sick.

Not being in the habit of growing tomatoes I didn't realise that a dose
of Bordeaux mixture before the event would have helped, of which I have
plenty (I buy a kilo at a time for regular treatment of my vines). I
tried spraying as soon as the blight appeared but, as most of you would
have told me, by then it was too late. At least with vines, if you spray
*immediately* any sign of mildew is apparent, then you can just about
get away with it. Not so with tomatoes/potatoes, it seems.

Ironically I have had no sign whatsoever of vine mildew this year!

David

--
David Rance
writing from Le Mesnil Villement, Calvados, France