Eddy wrote:
Nick Maclaren wrote:
When vinegar is used as a herbicide, does it act systemically?
That is not a question :-)
? You mean all herbicides ARE systemic? What I meant, more
accurately I admit, is "When vinegar is used instead of a herbicide
but for the same purpose as a herbicide, does it act systemically?"
I would like to use vinegar on the grass, provided it has a
permanent effect on the roots.
Not merely doesn't it have a permanent effect on the roots, it
doesn't have a significant effect on the leaves. It is purely and
simply a weak acid. You shouldn't take so much notice of the New
Age Merkins (which is where I assume that you heard of vinegar as a
herbicide and the other myths you have picked up).
No, actually the United States Department of Agriculture is doing a
lot of investigation into the use of vinegar and apparently USA garden
centres have long stocked strong vinegar specifically for this
purpose. All news to me too, but true. See:
http://search.usda.gov/search?q=vine...esheet=ARS&oe=
That was over 5 years ago, and used a higher strength acetic acid to obtain
"herbicidal" activity. Why the quote marks? Because it is not herbicidal -
it simply burns off the growth above the soil. That is more or less what
paraquat does. If you want to see a different comment on the
"effectiveness" (there, I've done it again) of acetic acid see
http://cahe.nmsu.edu/CES/yard/2004/041004.html.
Glyphosate should do what you want, and will not impair the planting
of groundcover, but may need several applications for deep-rooted
perennial weeds. It will not cause the trouble you are afraid of
in any normal soils. Alternatively, sodium chlorate will degrade to
salt, which will wash away, but will need repeated applications.
Thanks very much, Nick, for your assurance re. Glyphosate. Have you
used it yourself for turning a lawn into a garden?
My concern about it was triggered by the following summary of
research:
http://unofficiallyoptimistic.com/?p=24
The usual unscientific rubbish and selective reporting. Part of it states:
"In California between 1984 and 1990, glyphosate was the third most
frequently reported cause of illness related to agricultural pesticide use.
In 1997, the California Pesticide Illness Surveilance (sic) Program found
Roundup ranked as the highest caused of pesticide induced illness or injury
to people in California. It is not only the active ingredient (glycosphate)
that is dangerous, but several "inert" ingredients as well."
Have a look at
http://www.cdpr.ca.gov/docs/whs/pisp/97tbl4.pdf for the full
figures relating to that 1997 report. For glyphosate, there were totals of
11 definite/probable and 10 possible "Illness/injuries with confirmed
relationship to pesticide exposure". Now look at rotenone (the active
principle of that natural pesticide Derris Root) - the figures are 53 and 9
for the same categories. Even sulphur scores 24 and 30! Theer are many
other materials with a much higher score than glyphosate.
You may also like to read Monsanto's comments about the "toxicity" of
glyphosate:
http://www.monsanto.com/monsanto/con...llness_bkg.pdf
Of course, you may not like to hear any of that, and prefer this sort of
thing:
http://www.monsanto.com/monsanto/con...llness_bkg.pdf
If so, you may also like to know that tin hats won't stop the aliens finding
you. I haven't got a reference for that, but I'm sure that the truth is out
there
--
Jeff
(cut "thetape" to reply)