As Trospero says -- There IS consensus within the scientific community:
". . . a generally accepted opinion or decision among a group of people . . . "

There is ONE looneytunes who does not ACCEPT established science.

I'll stick with science.

I just left the National Clean Plant Network Tier II-Roses meeting in Shreveport Lousiana. Virtually all of the scientists (virologists, horticulturists) working on rose viruses in the US were there, as well as major producers, regulatory people, etc. Researchers from universities in California, Iowa, Texas, Oklahoma, Wisconsin, Minnesota, Florida, and other areas were represented. It was a fascinating and rewarding meeting. We had a great discussion of rose virus diseases. As I've said before, there appears to be complete unanimity among researchers on a number of points, strongly supported by the discussions at this meeting:

1. Rose rosette is the FAR more concerning virus in American roses, orders of magnitude more important than rose mosaic.

2. Rose mosaic in the US is virtually always caused by PNRSV or ApMV. Arabis mosaic (ArMV) is never found in US roses.

3. While there are 22 other viruses known to infect roses, somewhere in the world (some of them in the US), in general they can probably be ignored as being either exceedingly rare, or harmless to productivity and performance of the rose, or so obvious and symptomatic that they would not normally enter commercial lines at all. So while they are not of zero concern to the research community, and certainly their continued study is of academic interest, their importance is considered incredibly less than mosaic, much less rosette.

4. To date, spread of the mosaic-causing viruses in the US has never been demonstrated in Rosa, by pollen, seed, insects, mites, on tools, or ANY other method other than graftage. At this point, there is also no strong suspicion of any such spread, since natural spread appears not to be occurring. Failure to demonstrate such spread is surely not due to a lack of trying! Researchers have tried every means imaginable to provide the opportunity for spread, if it could happen, and in all of the massive research, it has not happened. Ever. Not once.

5. Field spread by natural root graftage has been demonstrated at FPS Davis among very closely-spaced plants in a research plot, and is suspected by some, in closely planted commercial nursery fields, but has never been demonstrated anywhere but in Davis's research plots. (Note that this ongoing suspicion is now many years old. Still not a single actual demonstrated find in a commercial nursery field!)

The quote from Golino et al. is interesting, in that it demonstrates one
of the problems with arguments in this discussion -- Quote of some
nursery's opinion, from a 9-year-old publication, is used as proof that something actually happened. (The other quote above is from a 2005 paper -- 11 years old now!) Yet Dr.
Golino et al., as of this morning, STILL have not
demonstrated any such spread, and are unaware of any DEMONSTRATED such
spread, in the nursery industry. The rumor remains a rumor. Dr. Golino agrees
that it is most likely a mix-up at some level in the nursery,
where scion or stock was believed to be clean, but was not. In any
case, there is no evidence for (and no serious suspicion of) mosaic
"returning" to properly certified plants, ever, other than, perhaps, by
root-grafting of very closely spaced nursery plants. And even that
would be highly unlikely, since most nurseries grow their plants with
each variety in an isolated block of rows, so the super-close plants are
all the same scion source on the same rootstock source. Even if there
were an adjacent infected variety present, it would be highly unlikely
to be close enough to form root grafts. I don't want to beat a dead horse, but again I emphasize, such spread in a commercial nursery field has never, ever been demonstrated.

6. None of the agencies who provide certified indexed material have ever heard back from a customer of mosaic "returning" at a later date. So while the Florida extension newsletter article referenced earlier says there were older reports of such an event, the actual producers of that certified material have not heard such complaints from their nursery clients. Again, old unsubstantiated rumors do not make facts.

Because of #6 above, I have to wonder what's going on there -- something must have triggered the rumor. I do have a strong hunch. There was a time, near the end of J&P's difficult history, when they had their own virus clean-up program, and they guaranteed sending out virus-free material. There were times when that definitely was not happening (we received infected material from them), apparently due to major problems in their very secretive system. We've known that for a long time. So such reports of virus "returning" may actually be related to J&P's having sent out material that should never have been certified in the first place. I think that's a highly likely scenario. And of course that program has been defunct for a good number of years. In any case, no spread or "return," by any means, has ever been demonstrated, other than in known root grafts in closely planted plants in UC Davis's research facility.

There will always be rumors and hearsay. But these are the facts, as known to the scientific community, as of June 2016.

Back to worrying about catching kuru from bottled water...

"There was a time, near the end of J&P's difficult history, when they
had their own virus clean-up program, and they guaranteed sending out
virus-free material. There were times when that definitely was not
happening. . . "

Hey Malcolm! Did you know that J&P's "research" facility (i.e., where they did their breeding) was for many years about 2 miles from my house?

The land was the former Armstrong Roses (Not Armstrong Garden Centers) facility, which J&P acquired when they took over Armstrong. Part of the facility (which I never saw opened ) was a fully-equipped tissue-culture lab. Armstrong sunk a TON of money into that tissue culture deal, hoping that it would be a road away from RMV. They went resoundingly broke..

I used to spend a fair amount of time down there, and got to know Keith Zary and John Walden pretty well -- and we talked about virus.

There HAD been an effort to clean up J&P's stock -- until [corporate decision] they acquired Armstrong's assets. Plants, as well as that facility. All of the Armstrong cultivars were dumped in with the J&P. It quickly became impossible to keep them separate.

At that point, J&P's effort to clean up what they had ground to a halt. I don't know if they ever tried again later, but I don't think they did while they were still working here.

I always thought it was sad -- that they started out with a clean seedling, which was infected right there, as soon as it was budded onto rootstock.

Thanks Jeri. Yes I used to correspond rather regularly with J&P's virus folks. I think for a while they were doing a good in-house job. But then with the corporate changes, they became very secretive, then their lead researcher quietly disappeared, and soon after that (probably due to the Armstrong acquisition), they became very unreliable about virus certification. I really think the historic rumors that cloud the facts about virus management in most, or perhaps all cases, may go back to their unfortunate history.

I suspect so, Malcolm. What a pity that it all fell out the way it did. J&P was in a position, then, to do some real good. :-(

I am definitely out of my depth here. Thank you all so much for the enlightening information. I am somewhat reassured now. I will say this. I am WAY more concerned about the deer thinking my roses taste like chocolate than I am about RMV infection. As you can see by my pictures, I made a little nuisance fence around my roses. It has been extremely effective. The only bad part is that it doesn't look very nice. At least I have roses I can look at and not cane stumps. :) Here are a few I just clipped:

You're roses are looking beautiful. I'm sorry about the deer (there hasn't been one here for a century, at least) -- I HAVE seen what hungry rabbits can do, though.

I saw a mature plant of 'Mothersday' eaten to the ground over 24 hours -- so I get the idea. You definitely have my sympathy.

The following was stated in this thread: " Yes I used to correspond rather regularly with J&P's virus folks. I think for a while they were doing a good in-house job. But then with the corporate changes, they became very secretive, then their lead researcher quietly disappeared, and soon after that (probably due to the Armstrong acquisition), they became very unreliable about virus certification. I really think the historic rumors that cloud the facts about virus management in most, or perhaps all cases, may go back to their unfortunate history.

(The bold was added by me, H.Kuska)

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

H. Kuska comment:

Apparently there are two versions of this story:

"I have an acquaintance here in Southern California. She is of the mentality,
"absence of light black and Resurrection White", no gray areas in anything. She
was, for many years, a rabid exhibitor, to the point of having multiple florist
freezers in her home to hold her blooms for shows. She had dozens of portable
gazebos to move around her garden to protect the buds as they formed. She was
determined to grow uninfected varieties only as symptoms would disqualify her
entries. J&P had begun their VI program and reserved the VI plants for
specific states as the laws in those states had changed, making it illegal to
supply virused stock across their state lines. She badgered J&P for their VI
stock, then had it tested. Surprise! The results were that the VI stock was
infected with the specific viruses tested for. She loosed her wrath on J&P
and the PhD who ran the VI program. They replaced the plants, which, in turn,
tested positive. When she contacted J&P again, she was told the program had
been dismantled and the woman PhD in charge, reassigned as they found, even when
grown in "sealed greenhouses with no possibility of spread, the viruses
spontaneously regenerated". They refused to replace the stock a second
time."

The
above was posted on Fri, Nov 5, 2010. This was the link:
http://www.rosehybridizers.org/forum/message.php?topid=31712#31864

The Rose Hybridizers Society changed its web page to another server. Unfortunately, I have not been able to find the new link equivalent

================================================

"But a sanitary environment is just one safety consideration where fresh goods are prepared. So along with acting as a “live cleaning manual,” as Food Safety Manager Charlene Harwood, Ph.D., says, the database generates daily Good Manufacturing Practice (GMP) checklists. These cover items such as general plant conditions, pest activity and, the health and dress of personnel, which supervisors sign off on before the day's work commences. “It's like a pilot's checklist,” Harwood says."

http://www.foodsafetymagazine.com/magazine-archive1/aprilmay-2001/bear-creek-safety-database-bears-fruit/

Henry -- I knew that woman, too.

The period of time in which she was active was considerably after the end of J&P's attempt to clean their stock -- so it was not relevant to much of anything.

She is long-gone from the rose scene, and her departure was not particularly mourned.

I know two of my DAs are virused. My Heritage (on Dr. Huey) shows virused leaves from time to time. Right now in fact. So the thought that hot weather keeps it at bay is not true in this case. The other, Tradescant, is grafted on Fortuniana from a reputable nursery has only shown virused leaves once. It was just planted so we will see what happens. But I've had Heritage for over 10 years and it grows and blooms well.

I did have a climbing Iceberg, which I loved. It was virused which I think helped to cause it's demise one very cold winter. Of course it was also a bad blackspot magnet, so maybe that weakened it too.

Anyway, I wouldn't worry about it too much. RRD is much more of an issue.

The following was stated: "My Heritage (on Dr. Huey) shows virused leaves from time to time. Right now in fact. So the thought that hot weather keeps it at bay is not true in this case."

H.Kuska comment: Not all viruses that infect roses have a temperature dependent immune system response. For example:

"Lack of temperature dependence of the leaf symptoms

The following from the 2013 paper was also of interest to me:

"The common rose viruses apple mosaic virus (ApMV) (synonym rose mosaic virus [RMV]) and prunus necrotic ringspot virus (PNRSV) usually express symptoms early in the season, and the plants become asymptomatic later, with no possibility to detect these viruses. In contrast, the symptoms caused byRoYMV [19] persists throughout the season, and the virus can be detected. One possible explanation could be the suppression of posttranscriptional gene silencing [37], which is reported to be manifested by the P1 [33, 40] or HC-Pro [4, 30] peptides from members of the family Potyviridae.""

https://sites.google.com/site/roseyellowmosaicvirus/

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

This is an old quote from U. California, Davis:

""A 5-acre garden on the University of California at Davis campus holds 400 of the most commercially important rose varieties. Researchers are maintaining these plants as samples that are tested and shown to be disease free. Some rose varieties can carry rose mosaic virus without showing symptoms. In the past, some rose stock has even failed to show disease symptoms in the temperate California climate, but has later shown rose mosaic symptoms after being shipped to the eastern United States.

"We do a bio assay of these plants by grafting a bud onto an indicator variety and growing it for two years to make sure symptoms do not show up," says Mike Cunningham, rose program manager at Foundation Plant Services. Cunningham made his remarks to rose experts from around the world as they toured highlights of California's floriculture industry following the recent Fourth International Symposium on Rose Research and Cultivation held in Santa Barbara, California, United States."

H.Kuska comment: The bold was added by me for emphasis.

http://forums.gardenweb.com/discussions/1606237/what-is-yellow-pattern-pls-do-i-need-to-get-rid-of-these

As I said in my previous post, at the National Clean Plant Network Tier II meeting for Roses, THIS PAST WEEK, there was absolute, unanimous agreement about the viruses causing rose mosaic and similar viral diseases, proper and reliable diagnostic procedures, the complete lack of spread in gardens, the lack of evidence of spread in nurseries, among all of the virologists and pathologists present, representing all the labs that work with these diseases. Quoting (and misinterpreting) old literature here is truly unhelpful.

And yes, Buford, PNRSV (by far the most common causal virus of rose mosaic) can show nice symptoms in hot weather. I have a 'Marchesa Boccella' that is symptomatic right now, in our garden, after weeks of 90+ days and night-time lows in the mid-70s. Sometimes it doesn't take much of a kick to get viral load to spike, and it can happen very quickly.

How did you test Marchesa Boccella to determine that the virus was PNRSV? If it was PNRSV, was it stressed by some external one time happening or does it show virus regularly (or on and off ) all summer?

Good question.

1. It
   consistently tests positive for PNRSV but not for ApMV or ArMV by ELISA (and
   ELISA remains the "standard" among virologists, for its extreme
   reliability when performed under ideal conditions -- and we always do).

2. We know
   its history (from Roses of Yesterday and Today, 1983) and their plants all carried PNRSV.

3. The
   symptoms are typical of PNRSV, but NOT typical of other, similar viral
   infections. We had a nice talk on that
   at the National Clean Plant Network Tier II -- Roses meeting last week, and got
   to see typical symptoms of many of the less-common viruses.
   While there are similarities, they are not the same. RoYMV symptoms are quite different.

4. It's
   easily and permanently removed by thermotherapy (we've had access to the
   "clean" form of it as well, for over 30 years, heat-treated in our
   lab).

5. Summer
   symptoms are not unique to this plant; we see "typical" PNRSV
   symptoms on many varieties, now and then, in summer. All it takes is a few hours of good
   replication conditions, and the plant can load up with virus.

Normally, the plant will show symptoms on just a leaf or two, on one branch. You really have to look for it in summer.

Of course we have not tested it for each of the
other 25 viruses known to affect roses, in the world, so I cannot guarantee absence of a second infection. But there has been no reason to do so. If you have a cold, you don't typically
demand to be tested for herpes, measles, polio, and ebola. In this case, there is no reason to suspect anything other than a "typical" PNRSV infection, as accounts for 99%+ of the rose mosaic infections in the USA.

Thanks for that, Malcolm. I think it's really helpful for folks to have a complete explanation.

One thing you said -- that a plant may show symptoms on just one branch -- only one leaf. I HAVE seen that, on plants that I knew (from their provenance) had to be virused ... a whole large healthy-looking plant with minute signs of virus on ONE leaf.

How easy it would be to miss that one leaf!

Yes, Jeri, it may be that the exact conditions were "right" for rapid replication only when that particular leaf was at the right stage in its development to support the build-up. That's pretty common.

Yeah -- I guess it is. Certainly provided an example for me to learn from.

I have had mosaic show up on my Climbing Yellow Sweetheart once every couple of years, and only on one or two leaves. I only found them because I went looking for them. I would otherwise never have seen the symptomatic foliage. And yet this is a total weed of a plant that outperforms most other modern cluster-flowered climbers.

My 'Bishop Darlington' is a similar story. I've twice seen "a" leaf with symptoms -- and plant is as big as a bus. God knows what it would be like if it was not virused!

I wish I had been aware of its eventual dimensions when we planted it.

Since one person continues to state there has never, ever, 100%, etc. etc. (in spite of my documentation), I wonder why the following precaution is being used by Davis according to this 2016 link.

" The FPS rose collection is regularly retested by ELISA for reoccurrence of virus. The plants are also visually inspected in the spring for virus symptoms."

Please note in the link: Copyright 2016 The Regents of the University of California, Davis campus.

http://fps.ucdavis.edu/roses.cfm

Also please notice that visual inspection each spring apparently is thought to be of some value.

Also notice that the Davis folks, themselves, this past week, at the NCPN-R Tier II meeting, agree absolutely with what I've been saying (we have always been in agreement, and have always been in close communication, over the last 30+ years). As did ALL other virologists there. Without exception. Notice also that the "documentation" is always hearsay or rumor; no hard indexing results. As scientists, yes, we always look for the worst-case scenario. So they (and we) keep looking for any source of contagion. Delightfully, after more than 30 years that I've worked with the disease, and over 40 for the Davis folks, we have NOT seen it happen.

H.Kuska comment: When the proceedings of the NCPN-R Tier II meeting are available, we will be able to judge what specific points Dr. Manners feels there are such absolute total agreement on.

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

The following was stated: " Notice also that the "documentation" is always hearsay or rumor; no hard indexing results"

H.Kuska comment: In the documentation that I have provided, I have tried to make it clear what was hard indexing (such as for the infected seedlings by Swift) and what was observation by credible people with first hand knowledge of the situation.

Apparently the Davis team took the reports of spread seriously as they undertook research to test some of the possible modes (but not taking into consideration the possible complication due to the temperature sensitive immune system).

Ludicrous beyond imagining. We have a person who has done no research
on this topic, ever, arguing against the honesty and integrity of the
entire research community on the topic.

Who is this Swift person and where did he/she claim to have seen seed spread? If you mean J. B. Sweet's paper, notice:

1. It's now 36 (THIRTY-SIX!) years old. No one since then has suggested such a thing. The exact quote from that paper is "PNRSV was detected in 1% of two batches of seedling Rosa multiflora rootstocks but no transmission of PNRSV in rose seed has been demonstrated experimentally."
2. As I've pointed out elsewhere, it is common in many countries to refer to nursery plants as "seedlings." While it does SOUND like these were unbudded, how do we know they were never budded? We don't and we can't -- the above quote of part of one sentence is ALL we have to work with.
3. B.J. Thomas (no not the singing one) did his seminal research on rose mosaic at the same time, at the same research station. Yet he did not report or suspect seed transmission in Rosa.
4. The quote itself indicates that even back then, there is no experimental evidence for seed spread.

As for what the virologists at the NCPN agree on, is the fact that the viruses causing rose mosaic in the USA have never been shown to spread from plant to plant, by any means, ever, other than grafting, and no one has even any strong suspicion that they might.

As for badmouthing Davis "to test SOME of the possible modes..." (again note that this is from a person who is not a plant virologist and has done precisely zero research on plant viruses in his entire life, so far as we know, badmouthing the leading lab on the topic on this earth!) -- one reason not to test all possible modes (whatever that may mean) is the complete lack of evidence that mosaic IS spreading. How can we determine "HOW" something is happening if we have no reason to believe it "IS" happening? Example: I'd like you to prove to me exactly HOW it is that all the cats in Austria have puppies for offspring, rather than kittens! And the concept that "they don't -- they have kittens like all other cats" must not even be considered here. I want to know HOW its happening, and I must promote the concept that you're dishonest or a silly fool if you don't explain to me HOW it is happening! That's the level of ludicrousness of this argument. Over and over, it is demanded that we prove how something that is not happening, has never happened, and is not suspected to be happening, is happening! Sheesh!

I think I'm done now. Must go back to worrying HOW kuru got into my bottled water, and how it can be that I remain asymptomatic and I've not died of it yet...

HAHAHA ... Well, MY puppies have not produced kittens, and I am grateful.

I'm grateful, too, that the scientific community continues to expand the boundaries of knowledge. I'm glad they're there, doing that, because I am not a scientist.

I benefit from their careful, repeated examination of their results, and it is their results I'm most-interested in. So, THANKS, Malcolm, for passing along the continuing results.

Dr.
Manners used words and statements like "badmouthing", and "arguing against the honesty
and integrity of the entire research community on the topic.".

Over the years, I corresponded
by e-mail with a number of rose virus scientists concerning the presence of a
temperature dependent immune system and other topics such as the use of Round-Up as evidence of root grafting, and the setting up of statistically valid experiments. The correspondences were cordial. Scientists do this. This is why prior to publication papers are subject to reviewers viewpoints and editors determination of changes needed. This is not "badmouthing".

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

I am surprised that Dr.
Manners feels that: "seedling Rosa multiflora
rootstocks" is not clear. The author is English.

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

Dr. Manners stated:
"B.J. Thomas (no
not the singing one) did his seminal research on rose mosaic at the same time,
at the same research station. Yet he did not report or suspect seed transmission
in Rosa."

H.Kuska comment: I do not understand Dr. Manners' statement. I discussed
B.J. Thomas's seed research in the same article.

https://sites.google.com/site/rosevirusinformation/home

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

An earlier version of my article above has been cited in
a recent reviewed published rose virus paper.

https://www.researchgate.net/profile/J_Tang/publication/257801675_A_survey_of_viruses_infecting_Rosa_spp._in_New_Zealand/links/54c6a7760cf238bb7d093f40.pdf

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

Dr. Manners stated: " one reason not to test all possible modes (whatever that may mean) is the complete lack of evidence that mosaic IS spreading. How can we determine "HOW" something is happening if we have no reason to believe it "IS" happening? "

H.Kuska comment: Perhaps the following will answer your question as to why the Davis group looked for natural spread (2011 paper presented at a meeting): "observations indicate a means of natural spread."

http://www.apsnet.org/meetings/Documents/2011_Meeting_Abstracts/a11ma356.htm

AND

"Observations by nursery growers suggest that plants propagated from clean disease-tested stock, rootstock, and scion do not always remain free of RMD. It is not understood how or why disease appears in “clean” planting stock over the years. Efforts to demonstrate spread of RMD under field conditions to date have not been successful. This study was initiated at the request of the rose nursery industry, which is looking for improved management strategies for RMD. The primary goal of the work was to attempt confirmation under experimental conditions of the observation that RMD spreads in the field."

Please note that the bold was added by me, H. Kuska.

This is from the full paper of the following abstract link:

http://www.actahort.org/books/751/751_26.htm

All ancient water under the bridge. CURRENT virus researchers at Davis and elsewhere no longer suspect any of the above.

And to suggest that Davis did not think to test some aspect that you think important is, indeed, "badmouthing."

Hi, I've just been led to this thread, because of my recent thread about RMV. I've noticed that a brand new Austin rose and a 4 year old Austin rosoe has RMV. Can RMV be spread by pruning shears? If so, then probably all of my roses have it. :(

Carol

Is asking how those virii found their way in roses in the first place a reasonable question?

Nick the straight answer is that it is not known with certainty, but the theory is by grafting to a fruit tree that was naturally infected (PNRSV and ApMV both spread naturally in fruit trees). If someone who knew just enough about botany and grafting to be dangerous were to have realized that peach trees and roses are in the same family, and tried grafting a peach scion to a rose rootstock, and then the graft failed, and then, rather than destroying the rose, he/she instead grafted a rose to it, later, that would be all it would take.

Carol, no to the pruning shears. No contagion of any kind has ever been shown in a rose garden.

And, Nik -- we play all sorts of speculative games about who might have made that first fated attempt to graft a fruit tree and a rose together . . .

It would really have to have been someone from whom an infected plant could have then gotten into commerce. Once that happened, the U.S. system of rotating rootstock cuttings back into the field did the rest.

I'm sure they meant well, but they sure made a mess of things.

Concerning when we first became aware of virus infection in roses.

https://sites.google.com/site/firstappearanceofroseviruses/home

Viruses probably / apparently have coexisted with other forms of living material as long as living material existed.

https://en.wikipedia.org/wiki/Virus

https://www.google.com/?gws_rd=ssl#newwindow=1&q=how+long+have+viruses+existed+on+earth

Thank you sooooo much Malcom!!!! Kudos to you!!

Carol

Grafting has been practiced since the ancient times.

To me, a non expert but rational and scientifically educated person, it seems obvious that various virii may have been existing in roses since forever but it seems equally obvious that science believes that the main, so far, identified culprits for RMD symptoms are not 'native' but have been introduced to roses and cannot be transmitted by natural means. The above two statements are not conflicting and both can be true.

Exactly, Nick. The third factor, important here, is that European roses (and US roses before the 1920s) were mostly grafted to seedling rootstocks. It was only after the use of vegetatively propagated stocks began (most importantly 'Dr. Huey', but others as well) that mosaic had a chance to become epidemic. More than 90% of the US crop in the 1970s was said to be infected (estimated by Dr. L. C. Cochran of Oregon State U.). We've brought that number down dramatically in the years since, but it remains a problem with some nurseries and in some varieties. Since the use of seedling stocks remains popular in Europe, infection rates there have always been far lower, and remain so. When I travel in Europe and happen to see mosaic symptoms, I always try to see the label to find out what the plant is. Virtually always, it's a variety of American origin. While there very likely are other viruses "native" to roses, none of them (except rose rosette) has proven to be sufficiently damaging to be of any significant concern.

No one questions that grafting contributed to the spread. The question of importance here is whether the mosaic viruses can naturally infect roses.

A recent Chinese paper reported PNRSV in wild roses. A comment was made (in another thread) that possibly wild does not mean wild. I would expect that that could be easily answered by the committee by correspondence.

Part of why I am interested in seeing the report of the meeting is to see how this was handled.

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

There was an old report that PNRSV (called by one of its equivalent names) was found infecting wild roses in the U.S. I had pointed this out in earlier thread(s).

I would like to see this discussed in the report.

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

There is a rose grown for a long time in the middle east for its oil content. It is a hybrid so it cannot be grown from seed. The only method of procreation that I know of is by cuttings. When samples were tested for virus the results reported are:

". Although ArMV
and ApMV were found in all surveyed areas, PNRSV
infection was only detected in two locations" (this appears to be an error, from the table PNRSV was found in 8 locations and absent in 2 - the areas in which it was not found had only 4 samples and 12 samples tested). Now back to the quote-"Among
the samples tested, ArMV, PNRSV, and ApMV
were found in 51.8%, 35.7%, and 17.8% of the
collection, respectively. However, mixed infections
of ArMV+PNRSV, ArMV+ApMV, PNRSV+ApMV,
and ArMV+PNRSV+ApMV were also detected
in the samples tested."

http://www.tandfonline.com/doi/pdf/10.1080/01140671.2009.9684247

I would like to see this discussed in the report.

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

The reader may be interested in the the report that PNRSV has been detected in weeds around the oil rose fields.

http://sipav.org/main/jpp/index.php/jpp/article/view/2983

Why include this? Scientists often look for "tips of icebergs". This suggests (to me) that one should look at whether pollen and/or insect(s) is/are responsible for this observation.

I would like to see this discussed in the report.

If the Turks do as the local growers over here do, then they use mostly budded R. damascena. I would be surprised if they do otherwise because commercial reasons for using budded plants are strong.

THIS IS INSANE!!! ONCE AGAIN, ROSE MOSAIC HAS ***NEVER*** been shown to be spreading in the USA. There are no suspected cases. NONE! Cats do NOT have puppies! Finding ancient reports from far corners of the earth (where research methods may or may not be the best -- note even the gross error in the paper quoted above), does NOTHING but damage the goal of mosaic-free roses. So what is the goal here? What happens to roses around the world is of some academic interest. But polluting this (and all other similar) threads here on GardenWeb, where people have asked about rose mosaic on a US-grown rose, only serves to alienate people and confuse the issue.

The Turkish paper also reports RRD on R. damascena in Asia Minor (that is from 2006-7). I have a feeling that this is a gross error also.. Probably some overjealous weed killer sprayer.. I certainly hope so.. Are there any other reports from places close by?

Malcolm - I'm so glad you're so knowledgeable!! We really need you on this forum, and thanks!

Carol

We can certainly hope that was an error, Nik. That we've not heard about it there again, since then, is promising.

The Chinese also reported a virus in roses similar to rose rosette disease.

http://onlinelibrary.wiley.com/doi/10.1111/mpp.12202/abstract;jsessionid=8B923270961986BC80D15679D64E7261.f02t02?userIsAuthenticated=false&deniedAccessCustomisedMessage=

And As noted in Alice Through the Looking Glass . . . when is a Raven LIKE a Writing Desk . . . ?

" RRD has been documented in Europe (that was reported at last August's Rose Research Symposium held in Germany) and they are very concerned about RRD too."

Quote from Dave Zlesak in:

http://www.rosebreeders.org/forum/viewtopic.php?f=2&t=54602

Really? How, when, were was it documented? I've only heard of a report from Poland which was never substantiated. Of course the Europeans are concerned. They should be.

Here it says it's absent from Europe and the Med (as of 06-2016)
EPPO Alert

But of course you choose to quote a Mr. Zlesak rather than EPPO. Why am I not surprised?

Nik, David Zlezak should be a reliable source, and he's an old friend, so I've written him for further details about the source and the veracity of the comment. Hope to hear from him soon.

Title: Rose Rosette may not be Native.

See:

http://www.rosegeeks.com/id9.htm

"Propagation: Rosa Damascena is propagated through one year old stem cuttings. It can also be propagated through the divisions of old plant, lateral sprouts with roots and seeds.

Stem cuttings are collected at the time of pruning in mid October to end of December; 20 cm long, 0.75-1.50 cm thick cuttings are planted in nursery; 2/3 of the stem length is inserted into soil. IB A @ 200-250 ppm is given to induce rooting. These cuttings are ready after one year for transplanting into main field."

http://www.tandfonline.com/doi/pdf/10.2478/V10133-010-0032-4

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" The cultivars and ecotype of Rosa damascena Mill. have been grown by using cutting or two old-suckers for many years"

"Stem cuttings are collected at the time of pruning in mid October to end of December; 20 cm long, 0.75-1.50 cm thick cuttings are planted in nursery; 2/3 of the stem length is inserted into soil. IB A @ 200-250 ppm is given to induce rooting. These cuttings are ready after one year for transplanting into main field."

"Rooted stem cuttings are taken out from nursery and put in the pits."

"The best time of transplanting of rooted cuttings in the field is mid of November to mid January. "

http://www.plantsrescue.com/tag/damask-rose/