On 24/11/2010 09:53, Janet wrote:
In , says...

In ,
Bob wrote:

The only problem I see is that DEFRA have not given it a licence to be used
as a pesticide, it has not been tested as such, and we therefor do not know
what damage it would cause to the environment as a whole. It might also kill
birds and others that eat the contaminated slugs for example, it might do
irreparable damage to the soil flora/fauna.

I doubt that very much. The chemical caffeine is not that nasty.
Curiously the LD50 for caffeine is about the same as pure glyphosate.

Yeah. And it might super-stimulate the slugs, so they go racing
round the garden, or even sprout wings and fly.

Given the massive experience we have of composting them in open
heaps, the effect on birds is almost certainly nil to negligible,
and we can be certain that it won't cause irreparable damage to
the soil flora and fauna.

If broken up tea/coffee leaves contained an effective
pesticide/deterrent/herbicide I'd expect tea/coffee plantations to be
pretty pest-proof/ weed proof, but they aren't. Growers contend with
multiple weeds/pests.

That doesn't follow at all. There are pests specific to a given host and
static monoculture like tea or coffee plantations always create problems
with the wrong pests finding a huge concentration of host plants.
Nicotine in tobacco plants is another extremely potent toxic insecticide
(extracts were even used as such in the past) but tobacco plants still
need protection from the various pest insects that have co-evolved to
tolerate or avoid the poison.

http://www.ikisan.com/links/ap_tobac...nagement.shtml

Regards,
Martin Brown