In article ,
"David Hare-Scott" wrote:

Brooklyn1 wrote:
"David E. Ross" wrote:

If you really want to kill the ivy, apply Roundup to the foliage
with a sponge or brush, which will avoid damaging the tree on which
it is growing.

That's much too risky. The ivy will quickly draw the Roundup deep
into it's roots where it will be deposited in close proximity to the
tree roots, whereby it will severely damage if not kill the tree.

How do you know this? When a plant is growing strongly roundup is drawn
down into the plant after it is applied to from the leaves, this is
docmentated as part of the way it works and the reason using it on dormant
plants is largely a waste of time . Where did you get the bit about it
crossing from the ivy roots to the tree roots via the soil?

David

https://en.wikipedia.org/wiki/Glyphosate
While glyphosate has been associated with deformities in a host of
laboratory animals, its impact on humans remains unclear.

Although the Roundup trademark is registered with the US Patent Office
and still extant, the patent has expired. Glyphosate is marketed in the
US and worldwide in different solution strengths under many
tradenames:[11] Roundup, Buccaneer, Razor Pro (41%), Genesis Extra II
(41% w/ Surfactant), Roundup Pro Concentrate (50.2 %), Rodeo (51.2%),
Aquaneat (53.8%), and Aquamaster (53.5%).[12] These products may contain
other ingredients, causing them to have different effects. For example,
Roundup was found to have different effects than glyphosate alone.[13]
Roundup herbicides are usually water-based solutions containing
glyphosate, a surfactant, and other substances.

Glyphosate kills plants by interfering with the synthesis of the amino
acids phenylalanine, tyrosine and tryptophan. It does this by inhibiting
the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which
catalyzes the reaction of shikimate-3-phosphate (S3P) and
phosphoenolpyruvate to form 5-enolpyruvyl-shikimate-3-phosphate
(ESP).[15] ESP is subsequently dephosphorylated to chorismate, an
essential precursor in plants for the aromatic amino acids:
phenylalanine, tyrosine and tryptophan.[16][17] These amino acids are
used in protein synthesis and to produce secondary metabolites such as
folates, ubiquinones and naphthoquinone. X-ray crystallographic studies
of glyphosate and EPSPS show that glyphosate functions by occupying the
binding site of the phosphoenolpyruvate, mimicking an intermediate state
of the ternary enzyme substrates complex.[18] The shikimate pathway is
not present in animals, which instead obtain aromatic amino acids from
their diet. Glyphosate has also been shown to inhibit other plant
enzymes,[19][20] and also has been found to affect animal enzymes.

When glyphosate comes into contact with the soil, it can be rapidly
bound to soil particles and be inactivated.[39] Unbound glyphosate can
be degraded by bacteria.[78] It has been proposed that glyphosate
applications increase the infection rate of wheat by fusarium head
blight.[79]

In soils, half-lives vary from as little as three days at a site in
Texas to 141 days at a site in Iowa.[80] In addition, the glyphosate
metabolite aminomethylphosphonic acid has been found in Swedish forest
soils up to two years after a glyphosate application.[81] Glyphosate
adsorption to soil varies depending on the kind of soil.
-----

Then there is the traditional "False advertising" and the ever popular
"Scientific fraud"
On two occasions, the United States EPA has caught scientists
deliberately falsifying test results at research laboratories hired by
Monsanto to study glyphosate.[95][96][97] In the first incident,
involving Industrial Biotest Laboratories (IBT), an EPA reviewer stated,
after finding "routine falsification of data", it was "hard to believe
the scientific integrity of the studies when they said they took
specimens of the uterus from male rabbits".

--
Welcome to the New America.
http://www.youtube.com/watch?v=hA736oK9FPg
or
E Pluribus Unum
Green Party Nominee Jill Stein & Running Mate, Cheri Honkala
http://www.democracynow.org/2012/7/13/green_party_nominee_jill_stein_running