Re: dormant oil
- To: t*@xtra.co.nz, m*@ucdavis.edu
- Subject: Re: dormant oil
- From: h*@ccnet.com (Jerry Heverly)
- Date: Tue, 9 Feb 1999 20:10:05 -0800 (PST)
I can also remember being able to buy arsenical
>weedkiller freely, which was a favourite poison with thriller writers
>was it not?
>
>
>Tony & Moira Ryan <theryans@xtra.co.nz>
>Wainuiomata, New Zealand
I looked up the US law on organics and found that dormant oils and
lime-sulfur are both permissible.
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. 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.
Jerry Heverly, Oakland, CA
