FarmI wrote:
Does anyone know how long Bordeaux or Burgundy spray has to be on
peaches to give protection? I made up the copper sulphate segment of
the Burgundy spray yesterday, mixed the full recipe this morning and
sprayed but we have rain forcast in about 3 days time and I wondered
if 3 days on the plants will be enough time to work. Anyone know?

I think you are sweet. If it hasn't done the fungi present in 3 days it
won't. As for those that blow in on the wind next week that's another
matter. I do all the stone fruit at this time with copper oxychloride (very
similar, works the same way) and I only do it once. Seems to work against
peach leaf curl which is a fungus regardless of dew or rain a few days
later.

David