Thanks. You got my answer

JAYK link is to a 1998 reference. It does not appear to be a paper whixh was published in a recognized scientific journal that has a peer review policy.

This link is to a 2006 peer reviewed paper:

http://stopogm.net/files/RGTNTPVR.PDF

Here is a link that might be useful: link for above

What we do not know about the glyphosate products is what happens when they are mixed with the inert ingrediants used. Since the inerts are GRAS (Generally Recognized As SAfe) the EPA does not require testing of those products together with the active ingrediant. Since chemist have known for eons that mixing two chemicals can produce a much more potent chemical (think Agent Orange of Viet Nam) anytime two, even GRAS, chemiclas are mixed there should be long term studies to see what the affect of this mixture will be before the product is even allowed on the market.
One major problem we have today is that the EPA and the FDA depend on the manufacturer to tell them the product they wish to sell is not harmful, a situation similar to the folklore tale of the fox guarding the henhouse.

Ancient orange was contaminated with dioxin.

The study linked to above refers to container culture of seedlings in extremely close proximity, with soils of several types and refers to subtle effects such as inhibited acquisition of micronutrients in these non-target seedlings. It does not invalidate my comments, nor the conclusions of the California Dept. of Pesticide Regulation document which drew its conclusions from peer many reviewed studies. In real world conditions and typical garden soils, non-target herbicidal effects at the root level from glyphosate applications do not occur. Of course if clay particles are not present, such as in extremely sandy soils, and enough glyphosate is applied, there can be such effects, although the distance is limited. These conditions are unusual which is why glyphosate herbicides are commonly used in even sensitive environmental situations with no negative effect to non-targets. The study even showed that in loess soils they did not see the micronutrient inhibition effects. The study has limited applicability and was aimed at ascertaining subtle effects that may occur in Roundup Ready agricultural cropping systems.

And given the original question of the thread, it is clear that the negative effects of using vinegar or salt on seedlings in close proximity in containers would dwarf the subtle effects of glyphosate.

The toxicological issues raised by Agent Orange had nothing to do with mixing its 2,4-D and 2,4,5-T components, they were due to the contamination of the 2,4,5-T with several dioxins during its synthesis, most notably TCDD. Also, the EPA does not depend on the manufacturer to tell them anything; the manufacturer pays for the laboratory and field studies to be carried out which are then assessed by EPA scientists. Glyphosate and Roundup products have been extensively studied since the early 1970s. There is no evidence showing some unexpected synergistic process takes place that substantially changes the toxicity of its components.

Extremely well stated, and most logically averred. Thank you, jayk. If only others would listen, unblinded, to the truth. Those that drag 2,4,5-T into the glyphosate realm are just reaching for the non-existant.
hortster

JAYK's reply ?????? Please point out what statements in the actual article you used to make the comment that: "The study linked to above refers to container culture of seedlings in extremely close proximity."

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The author's statements had to be approved by the editor and the peer reviewers.: "There is a common understanding that the widely used herbicide glyphosate is easily degraded and adsorbed in soils and thus, harmless for use in agriculture. We can demonstrate, however, that this conclusion is wrong and dangerous for farmers because in former risk assessments the behaviour of glyphosate in the rhizosphere was not properly considered."

AND

"From this glyphosate transfer from target to non-target plants (e.g. from weed to trees in orchards) we predict an increase in disease problems, particularly on soils with low micronutrient availability as already reported in the USA. In view of plant and soil health, we urgently call for a re-assessment of glyphosate as herbicide."
--------------------------------
Since this article was published in 2006, it appears that glyphosate manufactures' scientific laboratories have had sufficient time to challenge this research by presenting their own research in an independent reviewed journal. Can anyone provide a link to such a research paper(s)?

-----------------------------
The author of the California Dept. of Pesticide Regulation document may have used some reviewed articles but the conclusions that he reached were not subject to a recognized scientific journal review. Also, of course, he did not have access to the published scientific literatue published after his study so the question remains: is the California Dept. of Pesticide Regulation document valid in 2009? The link that I provided appears to answer this question (to me); but, of course, I am open to examining any published reviewed scientific study(s) that challenge the 2006 study.
----------------------------

"Please point out what statements in the actual article you used to make the comment that: "The study linked to above refers to container culture of seedlings in extremely close proximity."

If the study is read, the reader will find the following:
"In this study we investigated the potential transfer of foliar applied glyphosate, released from roots of target plants (glyphosate-resistant and glyphosate-sensitive soybean cultivars) to non-treated indicator plants (sunflower, coffee seedlings) simultaneously cultivated in hydroponics and in soil culture systems."
"Thereafter the seedlings were cultivated and subsequently transferred to nutrient solution or planted into rhizoboxes."
"Â seven seedlings of Round-up- sensitive soybean and three seedlingsof sunflower were cultivated together in pots with each of continuously aerated nutrient solutionÂ"
"Â two Round-up- resistant soybean seedlings and one seedling of sunflower were transplanted together into rhizoboxes filled with 300 g of an acidic sandy Arenosol from West Africa or with a calcareous loess sub soil Â"
"In a similar pot experiment, citrus seedlings were grown in green-house culture for 9 monthsÂwith 40 target plants of Brachiaria brizanthaÂ"

One study about a particular characteristic of a substance in particular situations does not instantly change the basic understanding about how that substance acts in every other situation. Individual studies only go so far, it takes competent interpretation by qualified scientists to put them into context with all of the other studies. The authors of this particular study attempt to draw a "prediction" from their finding regarding effects in orchards. This is a quite a long stretch from their actual study methodology and results and I doubt that other researchers would concur that the prediction has merit. Since glyphosate herbicides have been used in orchards for about 40 years, if these effects were actually happening it would have been likely noticed by now.

The link below is to another companies' glyphosate label"

http://wci.colostate.edu/Assets/pdf/Labels/Grasses/Herbicide/HelosatePlus.pdf

The following appears on page 32: "Avoid painting cut stumps with this product as injury resulting from root grafting may occur in adjacent trees."

So it appears that it has been noticed; but since the official line is "no spread", the field observations have been explained by root grafting.

-------------------------------------
In JAYK's first post he stated: "Unless there is a really huge load of the herbicide applied in a very, very sandy soil situation there should be no herbicidal effect on plants in the vicinity."

The use of "unless" also sugest that someone, somewhere observed something.

--------------------------------

A recent (November 2007) published reviewed experiment where glyphosate leaves the roots is reported at: http://www.springerlink.com/content/q0941n83w14wq825/

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"So it appears that it has been noticed; but since the official line is "no spread", the field observations have been explained by root grafting."

It is explained by root grafting because that is what is precisely what is happening: Glyphosate, a systemic herbicide, is carried in the plant vascular system, and in some circumstances it can move in this vascular system from tree to tree through root grafts. Root grafting can occur in either the same species, or in close relatives. Studies involving thousands of trees have shown that this kind of movement does not take place in almost all cases, but it can occur. There is no "official line", there is only what has been demonstrated by empirical evidence and laboratory and field studies.

As to my earlier comment "Unless there is a really huge load of the herbicide applied in a very, very sandy soil situation there should be no herbicidal effect on plants in the vicinity." Yes, of course this has been observed, that is why I included it. It takes place where application rates are high, and the soil profile is so bereft of clay particles (sand/gravel river bars for example) that the small amount of exuded glyphosate in the rhizosphere was not tied up and affected intermingled roots of non-target species.

"A recent (November 2007) published reviewed experiment where glyphosate leaves the roots is reported at: http://www.springerlink.com/content/q0941n83w14wq825/ "
Yes, glyphosate acts systemically and is moved into the root system to affect the plant. That is how it works. It "leaves" the roots primarily as the plant and its root system decays. It is then typically tightly bound up in the soil and is broken down by soil microorganisms. Nothing new or unexpected here; this has been shown since the original work on glyphosate was done, using radioactive tagging to determine how it moved in the plant once applied.

There are aumber of possible directions I could take in response to JAYK's (Wed, Aug 19, 09 at 15:41) post, but his response:

"Yes, glyphosate acts systemically and is moved into the root system to affect the plant. That is how it works. It "leaves" the roots primarily as the plant and its root system decays. It is then typically tightly bound up in the soil and is broken down by soil microorganisms. Nothing new or unexpected here; this has been shown since the original work on glyphosate was done, using radioactive tagging to determine how it moved in the plant once applied."

is completely off the subject of the actual paper. The paper has to do with the glyphosate leaving the live roots and entering the soil. Even the title should make clear what is being investigated. The abstract gives the basic outline. Here are some parts of the full paper:

Page 52:"Rodriques et al. (1982), Pline
et al. (2002), Guldner et al. (2005), and Neumann
et al. (2006) have shown that glyphosate can be
exuded from roots to soil, and cause growth inhibition
to adjacent plants and seedlings."

Page 59: This is the entire Conclusion section: " Conclusions
The translocation of glyphosate via the shoot to the
roots is fairly rapid and will take place also in
circumstances where no leaching/transport in soil
occurs. Our results give a strong evidence on the
significance of translocation on the detected soil
residues. We strongly recommend that translocation
process should be included both in leaching assessments
and pesticide fate models. Moreover, the
negative effects of glyphosate residues in soil to
conventional, non-resistant cultivars should be taken
into account."

Please notice the "negative effects of glyphosate residues in soil to conventional, non-resident cultivars...."

The following web article:

Author: Linda Chalker-Scott

Authors affiliation: Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University

Title: "The Myth of Wandering Weedkiller, "Glyphosate will move through root-grafts and kill non-target plants" The Myth"

This article seems to question JAYK's (undocumented) statement: "there is only what has been demonstrated by empirical evidence and laboratory and field studies.".

http://www.puyallup.wsu.edu/~linda%20chalker-scott/horticultural%20myths_files/Myths/Herbicide%20translocation.pdf
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Regarding proximity.
In my previous request I did not mean where you determined that they were seedlings, I was interested in how you determined that they were: "in extremely close proximity". Distances were not given in the article??????
In the following paper: http://www.actahort.org/books/751/751_26.htm

98 Sunflare roses were planted 1000 cm apart, "adjacent plants were carefully treated with the systemic herbicide Round-up". 5 of the 50 untreated Sunflare plants showed herbicide toxicity symptoms in some leaves (Table 3). The symptoms were mild and the plants subsequently recovered.

It may be possible that even 1000 cm spaced plants could form root grafts; but, if root grafts had formed, I would of expected more severe symptoms than stated above. After this research was presented at a meeting in 2005, I pointed out that rather than evidence of a root graft this may be rot to soil to plant transmission. Apparently further experiments are being done ("Translocation of the herbicide Roundup® from treated plants to adjacent untreated plants suggests that root grafting, in which the roots of adjacent plants grow and fuse to form a vascular connection between the plants, may be the mechanism by which this spread has occurred. Experiments to confirm this hypothesis are underway.").
----------------------------------------
Other papers that address topics related to soil transfer.
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Title: Fate and availability of glyphosate and AMPA in agricultural soil

Authors: Louise Simonsen ab; Inge S. Fomsgaard a; Bo Svensmark b; Niels Henrik Spliid a

Authors affiliation: a Faculty of Agricultural Sciences, Department of Integrated Pest Management, University of Aarhus, Slagelse, Denmark
b Department of Chemistry, University of Copenhagen, Copenhagen, Denmark

Published in: Journal of Environmental Science and Health, Part B, Volume 43, Issue 5 June 2008 , pages 365 - 375.

Abstract: "The fate of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) was studied in soil. Labeled glyphosate was used to be able to distinguish the measured quantities of glyphosate and AMPA from the background values since the soil was sampled in a field where glyphosate had been used formerly. After addition of labeled glyphosate, the disappearance of glyphosate and the formation and disappearance of AMPA were monitored. The resulting curves were fitted according to a new EU guideline. The best fit of the glyphosate degradation data was obtained using a first-order multi compartment (FOMC) model. DT50 values of 9 days (glyphosate) and 32 days (AMPA) indicated relatively rapid degradation. After an aging period of 6 months, the leaching risk of each residue was determined by treating the soil with pure water or a phosphate solution (pH 6), to simulate rain over a non-fertilized or fertilized field, respectively. Significantly larger (p
Link for above:
http://www.informaworld.com/smpp/content~db=all~content=a794423521
----------------------------------
Title: Glyphosate residues in a sandy soil affect tomato transplants.

Author: Comish, P. S.

Author affiliation: Hortic. Res. Advis. Stn., NSW Agric., Gosford, Australia.

Published in: Australian Journal of Experimental Agriculture, volumn 32, pages 395-399, (1992).

Abstract: "Glyphosate residues in a loamy sand soil were suspected of damaging transplanted tomatoes at Gosford in 1990. Field and glasshouse expts. were conducted to det. whether phytotoxic residues of glyphosate persist in this soil type and, if so, under what conditions. In the glasshouse expt, visible symptoms of glyphosate toxicity occurred in tomato seedlings transplanted into soil that was sprayed 1, 5 or 15 days earlier with glyphosate (360 g/L) at 4 L product/ha. Glyphosate also reduced plant dry wt. (16 days after transplanting), but only where soil nutrient deficiencies were car. after transplanting. In this case, seedlings transplanted 15 days after spraying suffered an ay. redn. in dry wt. of 57%. Greater redns. in dry wt. occurred where superphosphate (43 kg P/ha) was mixed through soil before spraying (75 v. 35% redn.). In the field, glyphosate residues reduced plant dry wt. 16 days after transplanting, even when transplanting followed spraying by up to 9 days, and possibly as many as 30. At 9 days, redns. of 50, 74 and 78% were recorded with glyphosate (360 g/L) applied at 2, 4 and 8 L/ha, resp. Effects of glyphosate on fruit yield were significant, but much smaller than effects on earlier plant dry wts. The phytotoxicity of glyphosate residues in this loamy sand results from a combination of inherently low P sorption capacity and application of superphosphate, leading to low adsorption of glyphosate by soil. This may be exacerbated when dry conditions occur between application and planting. Thus, a plant-back period of 3 wk could be considered safe when transplanting tomatoes into this sandy soil, provided some mixing of soil occurs at transplanting. It is recommended that farmers perform a simple bioassay to confirm safety."
------------------------------------
The soil pH appears to have a controlling affect on the fate of glyphosate in soil:

"Title: Influence of soil composition on adsorption of glyphosate and phosphate by contrasting Danish surface soils.
Authors: Gimsing, A. L.; Borggaard, O. K.; Bang, M.

Authors affiliation: Chemistry Department, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.

Published in: European Journal of Soil Science, volumn 55, pages 183-191, (March 2004).

Abstract: "The herbicide glyphosate and inorganic phosphate are strongly adsorbed by inorganic soil components, especially aluminium and iron oxides, where they seem to compete for the same adsorption sites. Consequently, heavy phosphate application may exhaust soil's capacity to bind glyphosate, which may lead to pollution of drain- and groundwater. Adsorption of phosphate and glyphosate to five contrasting Danish surface soils was investigated by batch adsorption experiments. The different soils adsorbed different amounts of glyphosate and phosphate, and there was some competition between glyphosate and phosphate for adsorption sites, but the adsorption of glyphosate and phosphate seemed to be both competitive and additive. The competition was, however, less pronounced than found for goethite and gibbsite in an earlier study. The soil's pH seemed to be the only important factor in determining the amount of glyphosate and phosphate that could be adsorbed by the soils; consequently, glyphosate and phosphate adsorption by the soils was well predicted by pH, though predictions were somewhat improved by incorporation of oxalate-extractable iron. Other soil factors such as organic carbon, the clay content and the mineralogy of the clay fraction had no effect on glyphosate and phosphate adsorption. The effect of pH on the adsorption of glyphosate and phosphate in one of the soils was further investigated by batch experiments with pH adjusted to 6, 7 and 8. These experiments showed that pH strongly influenced the adsorption of glyphosate. A decrease in pH resulted in increasing glyphosate adsorption, while pH had only a small effect on phosphate adsorption."
--------------------------------
This link takes one to a 2005 "Mobility and leaching of glyphosate: a review" scientific paper (please keep in mind that it cannot discuss papers published after 2005):
http://www3.interscience.wiley.com/journal/112100650/abstract

I am aware of Dr. Chalker-Scott's 2002 article. As I said, there have been anecdotal accounts of root graft transmission for some time, although it is rare. Her article could not take into account newer studies suggesting root graft glyphosate transmission, such as http://www.bulletinofinsectology.org/pdfarticles/vol60-2007-387-388ciccotti.pdf of 2007.

Unless the quinoa is genetically engineered to be glyphosate tolerant, it is not alive when the 45 day analyzation takes place, so the majority of the release is happening as the roots decay. Not having the paper puts me in the dark regarding this. It appears the study showed that 8 days after glyphosate application to quinoa seedlings, the roots had exuded 4% of the glyphosate total into the surrounding soil. When they analyzed the entire soil and root mass at 45 days later 8-12% of the glyphosate was found. In either scenario, extrapolated into landscape situations, not agricultural ones, this tiny amount of glyphosate would be quickly bound up in the soil and would not present a problem for nontargets unless they were in intimate root contact with the sprayed plants. This is evidenced by 40 years of use of millions of gallons of glyphosate herbicides where nearby nontargets are not affected by glyphosate applications. Only one of your newly cited studies has applicability to the thread's original questions; the rose study, which claimed that root grafts were responsible for the toxicity; he is not planting tomato seedlings into sandy soil deliberately dosed with glyphosate; nor does movement of glyphosate on sorbent particles in agricultural fields pertain to herbicidal effects.

The article by Dr. Chalker-Scott's was written when the label already carried the statement. Since this article is a web posting, it is not set in stone and could of been updated anytime she found evidence to change her conclusions. Have you sent her the 2007 reference you posted here? She did not challenge root grafts existence. She challenged that glyphosate passed through root graphs. The 2007 paper you cited did not address that point. They started out with the assumption of transfer only through root graphs was possible: "Second, trials applying a systemic, only phloem-transported herbicide in slanting cuts in the bark of infected trees were performed in a medium-aged apple trees orchard in order to proof root contacts." AND "As it is wellknown that glyphosate moves through the plants only within the phloem tubes (Casely and Coupland, 1985), this result indicates that the translocation of the herbicide from one plant to another happened through a phloem connection between the two plants due to a root bridge."

NOTICE the 1985 date for the "well known".

They did not consider the experimentally proven process of root to soil to roots even though the paper does point out that: "Furthermore, root contacts seem to be a common
phenomenon in nurseries and orchards in this region
(Adige Valley, Non Valley)."

The closer separate plants roots are to each other the greater the chance of glyphosate from roots to soil, soil to neighboring roots transfer.

What could of provided evidence of graft transfer? If 100% of the herbicide symptom trees also showed infection, and if none of the trees next to herbicide containing trees (that did not show herbicide effects) become infected. The actual results did not come close to this expectation: "Specific PCR detection in all trees revealed the presence of Ca. P. mali in 57% of the trees with herbicide symptoms. This is very close to half and thus stastically cannot be used to support their assumption.
------------------------------------------
Your comments about the other studies seem to miss the point that a root to soil, soil to other plant's root model requires experimental evidence for each of the processes involved. Thus, one must show that 100% of the glyphosate is not inactivated forever once it hits the soil, and that glyphosate can be absorbed from soil by roots.

I agree that there can be glyphosate root absorption from glyphosate exudation by other roots, but my point, and it is borne our by decades of actual use and by experimental evidence, is that such transfer is dependent on unusual soil conditions or very close contact with non-target roots. Unlike some herbicids, glyphosate applied to weeds does not move significant distances through typical soils to affect other plants. If this was the case it would have never been used as successfully as it has been in landscape and forest situations. The proof is in the experience of millions of gallons applied in landscapes and forests throughout the world for 40 years. To claim that the original poster would have non-target problems through glyphosate root exudation if he used glyphosate in his garden is simply not borne out by the facts.

The statement was made: "This is evidenced by 40 years of use of millions of gallons of glyphosate herbicides where nearby nontargets are not affected by glyphosate applications."

My (H. Kuska) comment: Problems were observed. The observed problems were attributed to root-to-root grafting and/or spray drift.

My August 20 post gave the published research results concerning the effect of soil pH on glyphosate mobility. If the originator of this thread has an acidic soil (low pH) this scientific paper is suggesting (to me) that the originator of this thread should be wary of using glyphosate near valuable plants. Other research warns of the affect of heavy Phospate applications. Particularly gardeners can have acid soil (lots of organic admendments tend to make the soil acidic) and to use heavy Phospate fertilizers. And, gardners have observed problems (I am basing this statement on discussions mainly on the rose forums.

Example comments see: http://docs.google.com/gview?a=v&q=cache:8WkNN-hjEpcJ:https://www.ars.org/pdf/ART-murderbyroundup.pdf+round-up+spray+drift&hl=en&gl=us

Non-germane inferences from these studies continue unabated. Yes, soil pH can affect glyphosate mobility, but this does not mean that if the poster has an acidic soil he will experience damage to non-targets in his garden. If so, we would have seen millions of glyposate injuries in landscapes and forests and agricultural fields in the first years of glyphosate use and it would never have become a popular herbicide. This has certainly not been the case for 40 years, in fact it is used in some of the most sensitive habitats in the world. Certainly gardeners on the rose forums have experienced glyphosate damage, as your link demonstrates, but a reader of the linked document will note they were all blamed on drift or spray residue. Unless the poster is growing things in extremely sandy soil with non-targets in close proximity, he will not experience non-target effects due to soil movement of glyphosate. I have evaluated ornamental landscapes and forest lands that have been treated with glyphosate and other herbicides for decades, and while many herbicides can commonly create problems in the root zones of non-targets glyphosate is not one of them, outside of quite unusual situations. I think at this point the original poster is well armed with adequate background information on the subject and further posting serves no purpose.

JAYK stated: "but a reader of the linked document will note they were all blamed on drift or spray residue."

The actual statement is: "The poison had apparently worked its way into the soil or drifted onto the roses".

You are quoting the Rosarian who was pointing out the Roundup damage to the roses in the garden who likely has no specific understanding or expertise of how herbicides move. The exposure had clearly come from drift, as the incident arose because a gardener had sprayed the turf in the garden with Roundup, not the rose garden, nor weeds in the rose garden. It is far fetched in the extreme to theorize that the Roundup traveled from the sprayed turf roots and over and into the rose garden to be taken up in the rose root systems. If you've ever moved hybrid garden roses you have found that their root systems are not far ranging. Rose foliage is very sensitive to even small amounts of glyphosate spray drift; this kind of misapplication happens all the time and was most certainly the logical explanation for the damage. As the article continued to explain, "Roundup is bound to soil particles and is not picked up by the roots." As the UC Davis website states:

"Roses are also very sensitive to glyphosate (Roundup and many other trade names), which can be absorbed through the green stems in addition to the leaves. Glyphosate damage may appear at bud break the following spring after a summer or fall application that contacts leaves or stems; symptoms include a proliferation of small, narrow shoots and leaves."

JAYK I was clarifying your statement. I did not intend to hold up the article as scientific evidence. Your Davis article is also not scientific evidence. The published reviewed scientific papers that I have presented handle that aspect. You then switched to attempts to cite "real world" experience.

Generally the scientific papers have introductions that cite "real world" problems as the reason for doing the research. I also pointed out that the actual product label warms about underground spread (but attributes it to root grafts) and that the scientific basis of root graft spread has been challenged since 2002. You were unable to produce any science to support root graph transfer (your provided example had the opposite effect since there was no correlation between the herbicide damage and disease transfer).

Jayk's cited section from Davis is particulary interesting: " Roses are also very sensitive to glyphosate (Roundup and many other trade names), which can be absorbed through the green stems in addition to the leaves. Glyphosate damage may appear at bud break the following spring after a summer or fall application that contacts leaves or stems; symptoms include a proliferation of small, narrow shoots and leaves."

Please note the: "damage may appear at bud break the following spring after a summer or fall application....". The rest of the quote: "that contacts leaves or stems;" appears to be just an assumption; if not please provide link to published research.

If the statement had been "late fall application" and if it came from a northern state, then I can see a possibility of the rose absorbing the glyphosate at the same time as entering dormacy. For especially summer application the published root to earth (or spray to earth), earth to root research suggests a much more probable explanation is that the spring rains ( especially if there had been the normal spring application of fertilizer) freed the soil bound glyphosate which was then taken up by the roots of the roses.

I do not know what documentation U. C. Davis utilized, but here is: "sprayed glyphosate early summer" - "damage next yesr" real world report.

http://forums.gardenweb.com/forums/load/prof/msg042250578096.html

Real world damage after rain: "I did lose a plant once when it rained soon after doing this. My garden is sloping, so I thought at the time that the rain could have washed the poison down through the ground."

From:
http://www.au.gardenweb.com/forums/load/oznative/msg1019484029828.html

From the same thread:
"You mentioned roses. This has been disputed before on GW but roses have many fine surface roots and weeds with similar roots mixed together with the rose roots, the roots are in contact with each other and translocation of the herbicide can take place. Glyphosate kills roots and all so it can kill the rose. This info was quoted to me a few years ago by a Monsanto representative."

Gardenweb postings blaming a lost plant on any sort of reason is not a valid way to establish validity for any assumption, particluarly when it runs counter to established understanding and vast amounts of experience. The first poster you refer to only stated he used "weed killer" and is worthless as even a relevant anecdote. The second poster doesn't even say he has seen what he describes. The remaining posters say they have not seen damage.

Herbicides can, and do remain in tissues of plants from unintended drift, and create unusual responses in foliage in following seasons. This is well known in herbicide science. As this reference book excerpt on IPM of pome fruit states: "Two types of damage may be caused by glyphosate, depending on when it is applied. When glyphosate is applied in fall and gets on trees, new growth is affected the following spring. Trees are slow to leaf out, and many small, puckered, almost needle like leaves are produced."
http://books.google.com/books?id=bd85xeKSensC&pg=PA192&lpg=PA192&dq=glyphosate+Integrated+pest+management+for+stone+fruits++By+Larry+L.+Strand&source=bl&ots=2MnbPzpSM7&sig=Bm0ceYt35JrWVom25xDGtULQfnU&hl=en&ei=mGmPSsqTOITqsQPF1sUO&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=&f=false

Or this from Utah State:
"Glyphosate may be stored over the winter in some plant tissues. Perennial plants such as lilac, honeysuckle, and poplar that are sprayed during the summer or fall may not have noticeable injury until the following season. This injury will appear as stunted, narrow, trap-like, and chlorotic leaves."
http://utahpests.usu.edu/plantdiseases/htm/non-pathogenic/herbicide/

Glyphosate is not "freed from the soil" by rainfall to create such damage. I suggest that if you wish to wander into such speculation, you vet it with scientists actually familiar with the decades of glyphosate research and with the competence to draw valid conclusions from the literature; no one posting on this thread is so qualified.

I did the "valid way" by posting reviewed scientific studies. You introduced the concept of accepting: "established understanding and vast amounts of experience". The "established understanding" concept has a problem because of possible manufacture's "hype". I am now attempting to address "amounts of experience" - real world information. A problem here is that when unintended damage shows up it is almost impossible for the homeowner to rule out drift.

The "weed killer" reference was in a glyphosate thread and in context (are there any other non glyphosate weed killers that claim "not freed from the soil") appears to be on topic. But, no one comment is critical so if a reader rejects it, so be it.

Regarding fall application. Please note my use of the season "fall". I already discussed that the next spring observed result was possible with an internal model. Perhaps I should of explained in greater detail. Glyphosate acts on a particular pathway that is utilized when the plant is growing. In fall plants are shutting down (particularly mature trees which are slow growing to start with. Thus, there could be some validity to not seeing the absorbed glyphosate effect until the next spring. The glyphosate could off also ran down the mature bark, entered the soil, then bound by the soil, and then released in the spring rains. Further experiments would be needed to distinguish which (or if both) mechanism(s) is/are contributing.

The summer observations (roses and azaleas) do not have that problem. Both would still have growth after the exposure to glyphosate. No damage was noted until the next spring. Your Utah State link now adds specific other plants licac, honeysuckle, and poplar to the summer application list. Thank you.

JAYK,s statement: "Glyphosate is not "freed from the soil" by rainfall to create such damage." Is just that a statement. I have presented the scientific evidence for what conditions favor soil release. The glyphosate was bound to particles in the soil (more or less depending on the pH and amount of competing phosphate). Water is the solvent that allows these bind/unbind processes to take place. pH is a description of the amount of hydrogen ion in solution - water solution. Please look at my "Wed, Aug 19, 09 at 21:07" for one example of the published reviewed science. I specifically pointed out several statements from the full paper including: "negative effects of glyphosate residues in soil to conventional, non-resident cultivars...."

Do not these scientists, editor, and peer reviewers meet JAYK's requirement: ".... scientists actually familiar with the decades of glyphosate research and with the competence to draw valid conclusions from the literature.

Posting a few gardenweb anecdotes is not addressing the experience of millions of applications. That the product has been used for decades in landscapes without soil movement being some big problem speaks for itself.

You continue to cite exceptions to glyphosate's physical property of inactivity in soil but fail to understand the most obvious point these studies raise: it takes unusual circumstances to create this movement, circumstances that are almost never seen in typical gardens.

As has been restated over and over, very sandy soils may allow movement but in typical soils as the poster, and the millions of users of Roundup likely have, there will never be an issue soil movement to non-targets. The proof is in the experience over millions of applications. All scientists familiar with all of the studies will agree that there are exceptional circumstances where non-target damage can take place but they will also all agree that this is not something anyone is likely to see in landscape situations.

If you are so worried that you will have non-target damage through the soil if you use Roundup, don't use it. But millions of users will continue to use it in landscapes and will continue to see no damage from soil movement, as they have for 4 decades.

JAYK I feel (from my experience in local rose clubs and as the former internet consulting ARS rosarian for scientific studies (or some such title) that gardeners have had problems but they were not in a position to question "no underground spread" and had to assume that it must of been drift in spite of whatever precautions they took (I doublt if most knew about the possibilty of weed root to desired plant root transmission).

Apparently Monsanto knew: earlier in this thread I quoted the following from another thread (the You was not you nor I): "You mentioned roses. This has been disputed before on GW but roses have many fine surface roots and weeds with similar roots mixed together with the rose roots, the roots are in contact with each other and translocation of the herbicide can take place. Glyphosate kills roots and all so it can kill the rose. This info was quoted to me a few years ago by a Monsanto representative."

The scientific reviewed papers that I cited did not "all" agree that it only happened in exceptional purposes. For example I cited a 2006 paper:

"There is a common understanding that the widely used herbicide glyphosate is easily degraded and adsorbed in soils and thus, harmless for use in agriculture. We can demonstrate, however, that this conclusion is wrong and dangerous for farmers because in former risk assessments the behaviour of glyphosate in the rhizosphere was not properly considered."

Notice that the scientists, editor, and reviewers approved "wrong and dangerous". In my experience as a scientist I expect that the producers of farm glyphosate products would have immediately assigned their in house scientists and/or commissioned paid research to see if they could produce scientific evidence to disprove the paper. The paper was in 2006, I could not find any such disputing paper (apparently you were not able to either); instead I found a November 2007 published paper that supported it.

Yes, there are conditions that favor spread and condition that will inhibit spread. Nature is complex. But to attempt to lump all conditions that favor spread into (the following is a quote from a statement that JAYK made in this thread): "unusual circumstances to create this movement, circumstances that are almost never seen in typical gardens." is in my mind the opposite of the actual situation, home gardens with acidic sandy loam soil are very common (even desired - "In general the best pH value range for soil is approximately 6 or 7 as this is the range in which most nutrients can be readily available" - http://www.gardenstew.com/blog/e3-9-soil-ph-and-its-effect-on-your-garden.html .

Home gardens with high phosphate concentration (and acidic pH) are also very common - http://searchwarp.com/swa290149.htm.

When scientists talk about sandy loam soil they are not talking about "very, very sandy soil situation" - see JAYK's first post, they are actually talking about a common soil: "Sandy loam topsoil is a material that most farmers are familiar with. Although unusual in urban Houston, it can be found north of town. It can be purchased or trucked in from a sight you are familiar with."

It is common for gardeners to use a sandy loam soil mixed with compost" "Most experts find the best soil combines compost with a sandy loam topsoil." The quote is from the same link. H. Kuska comment - please note - compost has an acid increasing effect.

The link for the last 2 quotes was left out of my last post. It is:

http://www.urbanharvest.org/programs/cgardens/startguide/soilsmulch.html

Sorry.

Then why has this damage not been seen for decades all over the world in millions upon millions of instances? If this damage is so very easily created by Roundup use in common soils, Roundup would have never even made it past its first year of sales. There would have been millions of non-target damages and the company would not have had a viable product. Since this product has been used without millions of root transmission damages in ornamental landscapes and forests for 40 years your assumption is clearly untrue.

Real world April 2009 evidence of glyphosate leaving the roots and having a negative effect on the plants:
"according to work done at Purdue University, Kansas State University and the University of Nebraska, some of the glyphosate sprayed onto the corn plants eventually is exuded from the roots and is detrimental to microbial activity."

http://files.tlhort.com/topicassets/attachments/ta_106_forage_advisor_april_2009.pdf

Glyphosate sprayed deliberately on genetically modified, glyphosate tolerant, Roundup Ready corn and its temporary drag on manganese and zinc uptake into the sprayed, targeted plant's roots has virtually nothing to do with the poster's question about comparative non-target effects of vinegar, salt and glyphosate in the soil.

The poster asked: "Now, wouldn't the round-up chemical stay in the soil and gradually mix with the rest of the soil? And it will make the entire soil affected by the chemical. Having said that, whatever I want to grow would not do well in that surrounding area at all. Am I right?"

Please note, the "not do well" part of the question. In my corn link, the corn grown where glyphosate was NOT sprayed did better than the corn grown where glyphosate was sprayed. i.e the corn grown where glyphosate was in the soil did not do as well. I do not understand why someone would feel that this observed effect does not relate to the original question.

This is a study about spraying glyphosate on Roundup Ready corn. The corn, genetically modified to withstand glyphosate, is sprayed with glyphosate. It is not a non-target transmission effect. The corn is not a non-target. And the effect even on this RR corn was only a transitory manganese and zinc uptake drag. This has nothing to do with the original post.

The same batch of seed corn is grown in 2 areas.

The first area (which I call the control) does not have glyphosate in the soil. The corn grows relatively good.

The second area has the corn that has been sprayed. It grows poorer. The scientists concluded that the glyphosate was given off by the roots and was detrimental to soil enzyme activity. Apparently this was of concern in 3 major agricultural areas of the U.S.

The following is from a reviewed published 2006 scientific paper.

"These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate−metal complexes in plant tissues and/or rhizosphere interactions."

http://pubs.acs.org/doi/abs/10.1021/jf0625196

The automatic link in my last post does not work, but the one given in the body of the post can be copied and pasted into the address bar. It works.

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Another recent (2008) published scientific paper.

Title: Glyphosate inhibition of ferric reductase activity in iron deficient sunflower roots

Authors: Levent Ozturk1, Atilla Yazici1, Selim Eker2, Ozgur Gokmen1, Volker Römheld3 and Ismail Cakmak1

Authors affiliation: 1Faculty of Engineering and Natural Sciences, Sabanci University, TUR34956 Istanbul, Turkey; 2Department of Soil Science, Faculty of Agriculture,
Cukurova University, TUR01330 Adana, Turkey; 3Institute of Plant Nutrition, University of Hohenheim, D70593 Stuttgart, Germany

Published in: New Phytologist (2008) 177: pages 899906

Abstract: "Iron (Fe) deficiency is increasingly being observed in cropping systems with frequent glyphosate applications. A likely reason for this is that glyphosate interferes with root uptake of Fe by inhibiting ferric reductase in roots required for Fe acquisition by dicot and nongrass species.

This study investigated the role of drift rates of glyphosate (0.32, 0.95 or 1.89 mM glyphosate corresponding to 1, 3 and 6% of the recommended herbicidal dose, respectively) on ferric reductase activity of sunflower (Helianthus annuus) roots grown under Fe deficiency conditions.

Application of 1.89 mM glyphosate resulted in almost 50% inhibition of ferric reductase within 6 h and complete inhibition 24 h after the treatment. Even at lower rates of glyphosate (e.g. 0.32 mM and 0.95 mM), ferric reductase was inhibited. Soluble sugar concentration and the NAD(P)H oxidizing capacity of apical roots were not decreased by the glyphosate applications.

To our knowledge, this is the first study reporting the effects of glyphosate on ferric reductase activity. The nature of the inhibitory effect of glyphosate on ferric reductase could not be identified. Impaired ferric reductase could be a major reason for the increasingly observed Fe deficiency in cropping systems associated with widespread glyphosate usage."

The link is: https://research.sabanciuniv.edu/10763/1/Glyphosate_inhibition_of_ferric_reductase.pdf ******BUT be forewarned,***** my security system indicated that it may not be a safe site.

5 more recent scientific papers have cited this paper; they can be looked at at:

http://scholar.google.com/scholar?cites=1636036598241325543&hl=en

When you look at the Google Scholar hits for the 5 papers, please note that the last one by Herique et.at. also has a paper citing it.
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