In article ,
Pam Moore writes:
| I have just picked my first tomatoes for 5 years, having lost all to
| blight for the last 4 years.
| This year for the first time I have used Bordeaux Mixture which is
| suggested as the nearest organic control.
| Now I am concerned about the white copper sulphate deposits on the
| fruit.
| Is copper sulphate toxic?

Yes, but not catastrophically so. You need micrograms of copper
a day, the odd few milligrams on occasional will almost certainly
do no harm, and the lowest lethal dose recorded is of the order
of a gram.

| Does anyone know how thoroughly I need to wash them?

Moderately. No need to panic, but do wash them.

| Has anyone else used BM? Advice is to spray weekly.

Yes, on potatoes, where the problem doesn't arise. Weekly seems
a bit excessive, but the issue for tomatoes is whether there has
been heavy rain since you last sprayed.


Regards,
Nick Maclaren.