Herbicide damage (especially Roundup) often resembles virus infection.

Yes, but up to now I think most/all would of thought that it happened a short time after application, not next year.

I sprayed round-up in the fall on some clover around the ground of the roses - right before the roses went dormant. In the spring when the roses started leafing out, they showed the herbicide damage. The damage was caused by the round-up going through the clover and the roots mixing together with the rose roots. I realized this because there were no leaves on the roses when the round-up was sprayed. I was pretty shocked when I saw the herbicide damage...

It took about a year for the damaged canes to grow normal looking leaves. Now I only spray 'lawn weed' killer near the roses.

I wonder how many roses I have removed because I "saw" RRD damage, and really I had sprayed weeds or bermuda too close to the rose roots. I often put the nozzle of the Round Up on top of the weed and squirt it. It has never occurred to me that the roots could be tangled and it could spread that way. Some roots have very long arms.

I hope Malcolm sees this thread.

Sammy

It seems likely that roses could absorb glysophate after dormancy or semi-dormancy through green bark of younger canes or dying leaves from which the plant is resorbing nutrients. In my climate, some roses keep some leaves through the winter. I've seen recommendations to use Roundup around the base of roses while avoiding the leaves, but I've always worried that spattering green canes would lead to uptake of the herbicide.

In the case of the summer applications mentioned in the quotation, if that actually happens, it would seem to involve the freeing-up of soil-bonded glysophate as Henry suggests.

Roundup symptoms breaking out in spring have been discussed here before. It is fairly common. Typically you see feathery new growth with oversize stipules at the base of leaf stems.

If weird growth suddenly shows up in various parts of the plant, rather than starting on a single shoot, that points toward herbicide rather than RRD.

Is there any evidence of rose roots grafting to non-rose roots? That would be news to me.

michaelg, the following is a quote attributed to a Monsanto representative:

"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."

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

As stated in my original post in this thread, I feel that the science has concluded that one does not need a graft, that there is roots to soil, and then soil to other plants' roots transfer.

Roundup when sprayed on the foliage of larger weeds works its way into the roots of the weed killing it. It seems that this process which can take several days to kill a weed continues to diseminate the product into the soil where it can be spread. I've sprayed round up on good sized weeds. A month of two after spraying Roundup roses that were 5 to 10 away from the long dead weed develop RRD like symptoms. The good is that while very ugly the roses seemed to survive after one bloom cycle of very strange looking growth and blooms.

I just saw those symptoms on a new rose near a path that I sprayed.

I am so glad to have seen this, because I was going to paint some weeds with Round Up if they were in the beds.

Thanks for this post.
Sammy

Science has not concluded that such root exudation/non-target root uptake occurs in typical garden soils with reasonable clay content. As has been known for decades, glyphosate herbicide is tied up tightly to clay particles and is inactive in the soil. In very sandy soils, or where there is intimate root contact with of the target to non-target there can be some transmission. And as noted above, rose canes will let Roundup through even if they do not appear green. Wick applications of weeds in rose beds will not typically result in ground transmission of glyphosate into rose roots. I have seen rose gardens that used glyphosate in the manner for decades with no damage ever noted. I have also seen even quite careful applications of sprayed glyphosate in rose gardens create damage since most people do not use the correct nozzles and use low pressure to eliminate fine spray particles. A more complete discussion can be found at the link.

Here is a link that might be useful: weed forum thread

The description "Tightly" is relative to pH and phosphorus content of the soil. The following paper appears to me (so far) to be the most complete study of what phosphate (commonly just called phosphorus in gardening circles) does to glyphosate binding.

------------------------------
Title: Effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils.

Published in: J Environ Sci (China). 2005;17(5), pages 711-715.

Authors: Wang YJ, Zhou DM, Sun RJ.

Authors affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.

Abstract: "Glyphosate (GPS) is a non-selective, post-mergence herbicide that is widely used throughout the world. Due to the similar molecular structures of glyphosate and phosphate, adsorption of glyphosate on soil is easily affected by coexisting phosphate, especially when phosphate is applied at a significant rate in farmland. This paper studied the effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils including two variable charge soils and one permanent charge soil. The results indicated that Freundlich equations used to simulate glyphosate adsorption isotherms gave high correlation coefficients (0.990-0.998) with K values of 2751, 2451 and 166 for the zhuanhong soil(ZH soil, Laterite), red soil(RS, Udic Ferrisol) and Wushan paddy soil (WS soil, Anthrosol), respectively. The more the soil iron and aluminum oxides and clay contained, the more glyphosate adsorbed. The presence of phosphate significantly decreased the adsorption of glyphosate to the soils by competing with glyphosate for adsorption sites of soils. Meanwhile, the effects of phosphate on adsorption of glyphosate on the two variable charge soils were more significant than that on the permanent charge soil. When phosphate and glyphosate were added in the soils in different orders, the adsorption quantities of glyphosate on the soils were different, which followed GPS-soil > GPS-P-soil = GPS-soil-P > P-soil-GPS, meaning a complex interaction occurred among glyphosate, phosphate and the soils."

This abstract is presented in technical terms. A quote from the conclusion section of the full paper will probably be clearer. On page 775 in the conclusion section, the following appears that is important in discussing whether glyphosate is available to the roots of a plant from the soil or is too tightly bound:

"Phosphate, which has higher affinity to soils than glyphosate, competed with glyphosate for the adsorption site of soils when they coexisted. Applying glyphosate in soil containing higher content of phosate will possibly increase the environmental risk of glyphosate transferring from soil to groundwater and surface water."

http://www.ncbi.nlm.nih.gov/pubmed/16312989

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

I often use RU on weeds around roses. So if I see a bit of weird growth on those roses, I don't worry. The first time it happened, it was a bit disconcerting, but now I'm used to it.

I did have 2 roses that had RRD and it was much worse. Plus it kept coming back after I cut off the offending canes. RU damage usually just makes for spindly growth with small leaves. No witches brooms or really deformed buds.

Most rose growers apply excessive phosphate, which, according to information in this thread, tends to free up Roundup in the soil so it could be absorbed by roots.

Some rose growers have discarded heavy soil with good clay content and replaced it with muck. Does muck, like sand, have a low ability to bind gyphosate?

Michaelg, the answer to your question about muck seems to be: yes, no, and/or maybe, see:

http://www3.interscience.wiley.com/journal/119616459/abstract?CRETRY=1&SRETRY=0

"Mineral soils significantly reduced the inhibitory effects of glyphosate on root growth. One muck soil inactivated glyphosate, but another muck soil and bentonite clay had little effect."

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

If your computer blocks the last link, try: http://www3.interscience.wiley.com/journal/119616459/abstract??

Here is a link that might be useful: shortened form of link