Re: dormant oil
Jerry Heverly wrote:
> I looked up the US law on organics and found that dormant oils and
> lime-sulfur are both permissible.
Hi Jerry
This is my understanding too, with the proviso that they should only be
used when strictly necessary and not for routine application.
>
> Re arsenic: Early in the 20th century the first real insecticides and
> herbicides were all arsenicals. They were used most notably to kill
> homopterans, sucking insects. Apple growers in the state of Washington
> used copious amounts against wooly apple aphid and other insects. As
> production increased they reached out for export markets and found willing
> buyers in Great Britain. Unfortunately arsenic accumulates in soil and
> plant tissues. In the early 30's a few people in England dropped dead from
> eating US apples. Oops, sorry, Luv.
Well, there's a real horror story in the best tradition!!!
I know there were some NZ orchards of similar vintage which had to be
abandoned when the trees began to die from the excess arsenic, but I
haven't heard we ever managed to actually KILL anyone. (mind, you we
have also always exported a lot of our crop to Britain, so one does
wonder!!)
Arsenicals and botanicals (pyrethrum, nicotine, ryania, et.al.)
remained the only mass-produced pesticides until German and US research
on gas warfare and chemical weaponry generated the synthetic materials
(most notably the herbicide 2-4-D) of the 50's.
And they have been unloading these further "nasties" on us ever since.
Interesting to talk to you anyway.
Moira
--
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata, New Zealand
