In article , "David Hill" writes:
| ".........So it's back to things like Bordeaux Mixture (Lime and Sulphur)
| Copper Etc
| Will have to dig out my old books... .........."
|
| "........They are one hell of a lot safer for humans. ........"
|
| Are they????????
| Very intensively used as an insecticide around 1900's,1910's, 1920's,
| 1930's, was Paris Green
| This was an Arsenic based compound.
| Then we had DDT........
|
| Yes lets bring back the old remedies

Clot. It is 40 years since I did chemistry, but I am aware that
arsenic and copper are different elements. Perhaps you have
forgotten. And DDT is a recent (mid-20th century) organochloride,
not a metal-based pesticide.

Furthermore, I should appreciate not quoting me out of context.
Here is the real context:

So it's back to things like Bordeaux Mixture (Lime and Sulphur)
Copper Etc Will have to dig out my old books...

They are one hell of a lot safer for humans. The lethal dose of
copper is something over a gram, and a minor overdose will rarely
cause long term damage. Copper is an essential trace element,
after all.

The simple fact is that the copper-based fungicides are one hell of
a lot safer for humans than any of the effective organic systemic
fungicides.


Regards,
Nick Maclaren.