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What's the best nursery free of Rose Mosaic virus?

strawchicago z5
12 years ago

I was checking on Rose Mosaic Virus and found an old thread where aimeekitty posted a picture of her "Queen of Sweden" bought from Roses Unlimited in July. The leaves looked just like Christopher Marlowe that I got from RU in July. I chopped all his infected leaves off, and he was robust in the summer.

We have a mild winter this year, but Christopher Marlowe shriveled up early by frost, while other Austins remained green. Henry_Kusha of Ohio warned that RMV infected roses don't survive the winter well.

I'm used to roses dying in my 5a zone - like the hybrid teas that I planted in full-sun in my last house. But for a zone 5b hardy shrub like Christopher Marlowe to shrivel up is rare. I winter-protected him by mounding soil in a bucket like others, and he's right next to the house.

What's the best nursery free of Rose Mosaic Virus? Many thanks.

Comments (150)

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    Paul, I entered this thread by commenting to Kim about what is know about an aphid spread rose virus in California (Thu, Jan 5, 12 at 0:01).
    I referenced Davis's report, a Chile report with a color picture of an infected leaf, and on Fri, Jan 6, 12 at 11:43
    I stated: "My original post in this thread was directed to Kim. Does Kim have to be concerned about receiving an aphid spread rose spring dwarf infected rose if he accepts a rose with yellow vein symptoms? Please see the link below."

    http://www.prevalentviruses.org/subject.cfm?id=58465

    (The above link is a report that this virus is widely prevelent in California.)

    Here is a link that might be useful: virus distribution report

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    I notice that the "Report on Davis Visit" is hearsay, not from a peer-reviewed published paper, and therefore, by Henry's own set of rules, utterly worthless and to be ignored, and indicative that the person posting such a link must be an idiot. I didn't make the rule; I just keep being hit by it, so fair is fair. We are mandated to assume it's entirely a lie.

    In all seriousness though, I do have to doubt that the writer clearly understood what was being said there. Now as for apical meristem culture in tissue culture, yes, that has been well-known and documented for many years. We've not used it since heat therapy is easier and more successful (100% successful). But it is certainly used for many plants.

    Then, of course, the last-posted link is about an unrelated virus, and so must also be ignored completely in this thread.

    And even if the claim about buds is true, my statement is still completely valid -- never once has such a claim been validated in the literature, and in this case, I have to agree (can you believe it?!?!?!?!) with Henry -- without that having been published formally, it must not be accepted as fact.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The visitor/reporter in his report distinguished between apical meristem culture in tissue culture and bud propagation. Hopefully this link will serve to help explain why I take his report seriously (plus that there existed a published reviewed scientific article that reports doing the same with infected rose cuttings).
    http://www.rosehybridizers.org/embryoculture.pdf
    --------------------------------------
    The statement challenged by me (H.Kuska) was: " To date, there is not a single documented (nor suggested) case of a cutting of a known infected plant turning up as a clean plant later." Please notice that I used the actual quote (in order to be scientifically accurate).

    I do not understand why anyone could conclude that the reviewed, published in a science journal, French article is not sufficent to indicate the quoted statement is not accurate.
    ----------------------------

  • jackie_o
    12 years ago
    last modified: 9 years ago

    Would someone please answer one question? How did the original rootstocks become infected? You guys have stated that the virus is not transmitted by cutting, pollen, proximity to roots etc. Was the first instance a naturally occurring virus in the rootstock? How did it end up on so many pieces of rootstock?

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    jackie_o the link that I gave on on Sun, Feb 12, 12 at 21:46
    refers to the strains of PNRSV that have been characterized. Hopefully this type of information will someday be useful to trace the evolution of PNRSV as it spread from species to species.

    Possibly a good control group will be the Damask rose as it has apparently existed as a cutting propagated rose for a long time. One of the papers that I linked to on: on Sun, Jan 8, 12 at 23:55 is given below. If the long term cutting propagation description is accurate, I would of predicted a very uniform type of virus distribution if natural infection was zero.

    Please especially look at the mixed infections.

    Here is a link that might be useful: Turkey rose virus situation.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    Here is the reference for suggesting that it may be an appropiate study rose:
    "The cultivation of R. damascena in the country was initiated during the 16th century (52)."
    "Bulgaria is based on the cultivation of a single genotype of the thirty-petaled R. damascena Mill f.Trigintipetala (47) which has been vegetatively propagated for centuries."
    "As mentioned before the same genotype has been reported by several authors as the main genotype used in Turkey and Iran for production of rose oil."
    "Crossings between R. damascena and other rose species and especially R. galica have been attempted by rose breeders (51), however these hybrids have never made their way to industrial cultivation because they show changes in the rose oil composition."

    Here is a link that might be useful: ROSA DAMASCENA � GENETIC RESOURCES AND CAPACITY BUILDING FOR

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Oh oh -- a report from Turkey -- a hot climate, so obviously it could not possibly be true. But let's assume it is true -- obviously they could not competently test for the presence of any of those viruses -- they are in a hot climate! They use the evil ELISA method! EEEEEK! All of what they say must, by definition, be false.

    But let's assume they really do have mosaic and they really do know how to test for it (Henry cannot possibly agree with this, but I can believe it) -- then he says "If the long term cutting propagation description is accurate, I would of predicted a very uniform type of virus distribution if natural infection was zero." But wait! That's totally backward logic. It is only if natural spread is NOT occurring that we could have differences in infections, in a crop grown from cuttings! Natural spread would tend to make the infections uniform. Something they are NOT seeing.

    Again, obfuscation and blather.

    I'm really annoyed that GardenWeb did not stop this thread at 100 posts. Now we have to put up with more nonsense. Oy!

  • roseseek
    12 years ago
    last modified: 9 years ago

    Malcolm, have you any theories about where the RMV in the US rose industry originated? Nothing requiring scientific studies nor officially filed documentation, but based upon anecdotal information, educated conjecture or other experience? Of course, I've heard the conjecture it originated with Burbank and his Island of Dr. Moreau experiments budding fruit and roses together. Thanks in advance, Kim

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following was stated: "I would of predicted a very uniform type of virus distribution if natural infection was zero." But wait! That's totally backward logic. It is only if natural spread is NOT occurring that we could have differences in infections, in a crop grown from cuttings! Natural spread would tend to make the infections uniform. Something they are NOT seeing."
    ------------------------------------
    H.Kuska comment. My suggestion is based on roses having an immune system. i.e. not all roses will get an infection if exposed, especially not all roses will get the listed dual and triple infections. If all roses were cuttings from an ancestor infected plant(s) from some original grafted plant being smuggled in, they will all show the same infection (if the virus was evenly distributed as some here apparently still believe) all cuttings would produce identical virused plants.

    Of course the actual behavour will probably be more complex than the first order model. I assume that new cuttings will be selected from the best preforming plants. Thus, there probably is a selection pressure abainst virused roses. Plus there ia reviewed published scientific paper that virused cuttings are harder to root. In virus spread studies, computer programs are used to fit the observed spread pattern to the possible models.

    Here is a link that might be useful: rooting of virused roses

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Kim, Yes, the accepted idea of where it came from (accepted by virtually everyone except one) is that it was introduced by failed attempts to graft fruit trees and roses together. This is conjecture, but makes complete sense. And since the disease was noticed only after 'Dr. Huey' became popular as a rootstock (rooted from cuttings rather than seed-grown), that system of growing stocks from cuttings allowed it to spread quickly and thoroughly through the U.S. crop. Of course one person disagrees with this, and will undoubtedly produce countless "valid, reviewed, scientific papers" to "prove" that it's been around for eons before that, but as usual, a careful reading of those papers will demonstrate that he is again misinterpreting or reading into those papers things that were not actually said.

    Notice that all discussion here of an "immune system" in roses is more of one person's made-up silliness. Yes, there is RNA interference in plants -- a subject he totally misunderstands and misrepresents, and it has long been known that one viral infection can affect the ability of a second virus to establish in a plant. But the concept of an immune system as suggested here, is not valid.

    Of course all of these bizarre arguments continue to be presented to support a false view of the entire situation -- that researchers are not able to determine where infection exists, that the disease is spreading in the field, that it behaves differently in different climates, etc. All of these concepts have been made up by one person and are completely at odds with what the entire rose virus research world knows or believes.

    So, we just keep producing clean plants, that remain clean forever. We see no surprises or conflicts at all. We have absolutely no trouble testing for the presence of the disease with 100% accuracy and efficiency. The subject is nicely cut-and-dried. All else here is a lot of hullabaloo for no possible benefit to anyone.

  • harborrose_pnw
    12 years ago
    last modified: 9 years ago

    Well, in answer to the original question by Strawberry, Heirloom says they have imported most of their roses from Europe, where this virus isn't a problem.

    Thought that was mentioning. Okay, back to our regularly scheduled program.

  • roseseek
    12 years ago
    last modified: 9 years ago

    The idea of importing from Europe to avoid virus is a very romantic one...except, by the middle of the last century, European nurserymen were already complaining about the virus infection we had already exported to THEM. Remember that virtually all AARS introductions were made by Armstrong. They supplied the budwood for them and they were well known for their infection of roses which passed through their hands. Remember also, many OGRs were exported to Europe from Roses of Yesterday and Today, who was also well know for their strain of virus.

    In Jack Harkness' book, Roses (published in 1977), he addresses the virus issue, speaking about the British irritation over our "sharing" it with them. He further states that one prominent American nurseryman stated he actually thought it added a "decorative effect" to the roses. We had it first and we've shared it freely around the world.

    In the 1990s, while visiting Vintage Gardens and being taken on a tour of the Korbel Winery by Philip Robinson then of the nursery and home gardens by Philip and Gregg Lowery, we spoke of our observations about the breadth of obvious symptoms. They stated they had personally observed symptoms on BRITISH RAISED ROSES, not American exports, but roses created in Britain, in Queen Mary's Rose Garden in Regent's Park.

    Granted, the use of seedling stocks for production should help prevent spread of infection. But, for any bud wood taken from already infected varieties, using seedlings for roots won't prevent the crop from being infected. Perhaps newer varieties may be prevented from infection, but anything older and already tainted will remain tainted until and unless it is destroyed or "cleaned", including infected Old Garden Roses. Kim

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following link gives what I found concerning what was known about early observations of rose viruses.

    Of course as a scientist I am interested in hearing what the basis(bases) of the statement: "but as usual, a careful reading of those papers will demonstrate that he is again misinterpreting or reading into those papers things that were not actually said." is(are).

    Here is a link that might be useful: first observation of rose virus infection

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    Did we also provide the British with nematode causing rose viruses?
    ---------------------------
    A reviewed scientific publication concerning rose virus in England has stated: "only SLRV was readily seed-transmitted, particularly in R. rugosa.". Please note the appearance of the word "readily".
    Also, please note: "Nevertheless, in soil containing viruliferous nematodes, AMV and/or SLRV were transmitted to c. 80% of healthy plants." Please note: "80%".
    -----------------------------------
    It appears to me that England would be hard pressed to blame the U.S. for what appears to be their most severe rose virus problems, AMV and SLRV.

    Here is a link that might be useful: In plantings of up to 7 yr none of the viruses was transmitted through pollen to healthy roses grown in nematode-free soil

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    Why is this discussion valuable?

    If you are the owner of a small rose distribution company, you are possibly/probably operating on a very low profit margin. Lets say you make every effort not to ship virused roses. Someone buys a rose (at a premium price relative to the big box store price) that sooner or later shows mosaic symptoms. You check the "common" literature such as the 2 articles on the ARS web page and find (for example): " Means of Transmission RM is believed to be non-contagious in the field, except possibly through rare natural root grafts. There is no evidence that it ever spreads naturally in the garden or nursery, or through pollen, seed, or seedlings 2. Extensive tests also have failed to transfer RM mechanically (e.g.,on pruning tools, grafting knives, etc.) 3. The only known means for transmitting the disease is by vegetative propagation."

    Also lets say you read in this thread the following: "If you mean rose species, that's probably not a useful question, since the disease is believed (by all but one person) never to be contagious, by any means other than human activity, in the field (by "human activity" I'm including planting them in very close proximity -- inches -- a way one would never grow a rose in a garden)."

    ----------------------------------------
    Lets say you did have a known virused rose planted (2 to 4 feet?) away from your new purchase. Sometime later you observe virus symptoms, call the owner of the company, he/she gives you what you feel is an unsatisfactory answer that his/her roses are not virused. So you post on a rose web page that this dealer should be avoided.
    ---------------------------------------
    It is important for dealers and rose growers both to know that the cited tests are possibly deficient in one or more of the following ways: 1) were not statistically valid, 2) used detection methods not appropriate (sensitive enough) for "real world" spot contact infection detection, 3) were carried out in warm areas in which the known temperature dependent virus immune system may of been able to fight off the attack.
    ------------------------------
    -------------------------------
    As an aside, Turkey's climate varies with area. The cited Lakes Area is sheltered from the heat by a mountain range. See the link below. The month with the highest average temperature is July (22 deg C (71.6F)) and the month with the lowest average temperature is January (-0.02 deg C (31.64 F)).
    http://balwois.com/balwois/administration/full_paper/ffp-1934.pdf

    Here is a link that might be useful: a rose hybridizers discussion with references to dealers

  • ken-n.ga.mts
    12 years ago
    last modified: 9 years ago

    I for one REALLY appreciate what FSC & DR Manners have done over the years concerning RMV. I saw first hand his work. I lived in Winter Haven for 20+ years and spent MANY hours on campus. I remember when the whole thing got started with a mass planting of a bunch (32 I think) of Double Delights'. You would have to be on campus to understand the work that goes into a project like this. When you see it first hand, you understand what's going on with RMV and how hard it is to clean up.

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    "---------------------------------------
    It is important for dealers and rose growers both to know that the cited tests are possibly deficient in one or more of the following ways: 1) were not statistically valid, 2) used detection methods not appropriate (sensitive enough) for "real world" spot contact infection detection, 3) were carried out in warm areas in which the known temperature dependent virus immune system may of been able to fight off the attack.
    ------------------------------ "

    Again, and as always, these statements are false and ridiculous. If people were seeing any spread in the field, they might be worth considering. But since there is no evidence for such spread, this discussion continues to be utterly without value. Again, as far as statistics are concerned, in the informal "experiment" of millions upon millions of roses in gardens, worldwide, for there to have never been even one demonstration of spread is pretty good statistics. And even if it were spreading at, say, a rate of 0.000000001%, the probability of it happening in YOUR garden to YOUR rose is likely far less than the chance of you winning the lottery while being struck by lightning. It's really, truly, not worthy of consideration.

    As for insensitive detection methods -- as I've stated many times, only one person in all the world would argue that we have ever failed, even once, to detect PNRSV and ApMV when they have been present. There is no inadequacy at all to the indexing methods being used -- they are 100% effective. NO ONE else disagrees with that. The claim that sometimes ELISA can't detect a virus in the field is misleading -- no one who knows what they're doing would consider trying ELISA under inappropriate conditions. The research showing that PCR was more sensitive was a very valid test to show that it could detect the virus when conditions were inappropriate for ELISA -- good information to know -- but note that those same researchers would NEVER routinely use ELISA as a means of diagnosis under those conditions! We're really not idiots. Since there is precisely zero evidence that any researcher using the "standard" methods of indexing has EVER failed to get the diagnosis right, even ONCE, in all of rose research history, again indicates that the continuation of this discussion is ridiculous.

    And the concept of warm climates affecting an "immune system" is unique to this one writer, completely lacking in any evidence for it. It's preposterous. He keeps proposing it over and over and over, as if it will become true at some point just because he says so. It is not true. He's mistaken. Notice that NO cold-climate researcher is claiming to see any spread at all, by any means, nor is any cold-climate researcher seeing/reporting ANYTHING different from the hot-climate researchers. It's entirely a made-up story believed by one very persistent person!

    And as always, all of his peer-reviewed references, while excellent papers, really don't claim what he says they are claiming, and they do not support any of these wild claims in the least.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following was stated: "If people were seeing any spread in the field, they might be worth considering. But since there is no evidence for such spread, this discussion continues to be utterly without value."
    --------------------------------------
    H.Kuska comment. Professor Horst (Cornell University, Plant Pathology) wrote: "PNRSV is pollen-transmitted in fruit trees. Pollen transmission is suspected to occur in roses also, since spread in the field is slow."
    Horst, R., K., book "Compendium of Rose Diseases", published by The American Phytopathological Society, St. Paul, Minnesota. pages. 26-27, (1983).
    A Google Book search with the search term "since spread in the field is slow" suggests that the information is also in the 2007 edition. Can anyone verify?

    =====================================
    The following appears in one of the 2 ARS web pages concerning rose mosaic viruses (linked to at the bottom of this post):
    "There have been some lively debates over exactly how mosaic spreads in roses. Aphids,thrips,pruning shears,contaminated soil,root contact and pollen have all been suggested (Cochran,1988;Davidson,1988;Horst,1983,Manners,1988)."

    AND

    "It seems likely that the unsubstantiated reports of natural or mechanical spread of the disease,which appear from time to time,are due to misinterpreted observations either the plants which appear to have contracted mosaic were infected all along and have just begun showing symptoms,or perhaps symptoms which are interpreted as being those of mosaic are in fact something else."
    ----------------------
    H.Kuska comment. Since a reference to: "Davidson H 1988. Letter to the editor. The American Rose Magazine.29(15):16." appears in the same ARS article, I am presenting a link where Davidson's letter is discussed.
    The link below which references Davidson's letter (he is a northern California rose hybridizer (with All American sRoses to his credit)).
    -------------------------------------
    http://www.rosebreeders.org/forum/read.php?2,1467
    ==================================
    Back to the ARS Rose Mosaic paper (linked to at the bottom of this post). The author states: "Only carefully defined and controlled test conditions,and indexing or ELISA testing for the presence of virus before and after the experiment,can give useful information on contagion. Other researchers have found no evidence from such properly controlled experiments that rose mosaic spreads by any means other than grafting or budding (L. C. Cochran,Oregon State University;Charlene Harwood,Bear Creek Nurseries;George Nyland,University of California; ). Our results completely support that premise:no contagion occurred from pruning shears,insects,or any other means."
    -------------------------------
    H. Kuska comment: Please notice that all of these references are personal communications. Have they later been published in reviewed scientific journals? Also, this is what I found about something published by the THE PROCEEDINGS OF THE FLORIDA STATE HORTICULTURAL SOCIETY.
    "III. MANUSCRIPT REVIEW AND PUBLICATION COSTS
    A. Review. Papers presented for publication in the Proceedings are generally published with some editorial changes. However, editors may request revisions if manuscripts are verbose, unclear, not in the proper style, or contain extraneous or improperly documented statements. The Society reserves the right to reject papers or to publish them as abstracts only as determined by the Section Associate Editor with concurrence of the Editor. In a case where the Editor does not concur with the Associate Editor, he shall notify the Associate Editor of his reason in writing."

    http://www.fshs.org/PDF/FSHS_Author_Instructions.pdf

    Was this the policy when this paper was submitted? i.e. Was it submitted to outside review by your peers?

    Here is a link that might be useful: ARS Rose Mosaic paper

  • kittymoonbeam
    12 years ago
    last modified: 9 years ago

    Dear Dr. Manners,
    First of all let me say thank you for doing this work. The plants I have gotten may have come from your program and they are well worth many times the price I have paid for them. There is no doubt that these roses are getting to be stronger plants with each passing year compared to infected ones I started with in the early 80s which have declined and mostly now replaced.

    Most of my questions have been answered but one. How do you choose which roses to treat and can this be done by request. I have a very pretty sport of a famous 70's AARS winner but sadly it came from a virused plant ( still going strong but is virused just the same ). I imagine it is time consuming and expensive to do the work so I wonder how you choose which roses to work with.

    Another question is
    If I want to try and save my sport should I try to have it budded onto stronger roots. Right now it is just one own root plant doing well.

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated. How many times must one say this? Notice that even Mr. Peer-Review himself has not cited a single peer-reviewed paper that has demonstrated such spread. NOT ONE! And that's because there aren't any.

    Remember, if peer review is needed for something to be true, then nothing HK has said on this thread (nor any other, ever) has been true, since NONE of his writing on rose mosaic nor any other aspect of roses has ever been peer-reviewed. I don't really believe that -- while peer review certainly has its place, it is NOT necessary for something to be believable or true. But apparently those are the rules here! And of course, the assumption above is that all of those great and respected rose mosaic researchers write one thing in their peer-reviewed papers, but then they tell blatant lies when they give personal communications! How amazingly ridiculous is that??? How low can one stoop? How naive can one be?

    Kitty, we have mostly treated plants sent to us by nurseries. There is a fee involved, which doesn't quite cover the real cost of the process (I have never received a penny of it myself -- I do the work strictly on a volunteer basis). We've also tried to emphasize the older varieties that UC Davis has not had an interest in. Email me if you want to discuss this further.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following was stated: "Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated."
    -------------------------------------
    H.Kuska comment. The Horst's quotation appeared in 1983 and appanently in 2007. What 2007 is telling me is that the suspicions have not been laid to rest. To use your own words ""Only carefully defined and controlled test conditions,and indexing or ELISA testing for the presence of virus before and after the experiment,can give useful information on contagion."
    I have attempted to document my statements that ELISA has been shown to have sensitivity limitations. I have attempted to documented my statements concerning present knowledge of temperature dependent immune system behavour. I have pointed out that scientifically valid experiments have to take into consideration sample size. One of the e-mails that I have received stated that he/she had contacted one of the top rose virus researchers and asked about proof of spread. The answer came back along the lines: there is no proof of lack of spread.
    --------------------------
    Observed spread has been reported. Until the properaly designed experiments are done, on my web page

    http://home.roadrunner.com/~kuska/info_about_virus.htm

    I state:

    "Thus, until spread research is done in northern climates, I recommend that basic precautions be utilized to prevent/minimize the possibility of above ground spread."

    Thus, I agree with the most recent California Davis Extension Service recommendation (which has survived at least one revision) to: "In the meantime, you need to remember that viruses can be transmitted by pruning and cutting shears. Virus-infected plants should be pruned last and/or have their flowers harvested last. To be extra cautious, wipe your cutting shears with alcohol (rubbing alcohol is good) or a 10 percent bleach solution between plants."
    ---------------------------------
    I feel that the ARS membership would be better served to have this paper as a source of information concerning viruses. Apparently the California Extension Service, Davis feels that way for the citizens of California.
    ----------------------------------
    As I cite on my web page this is what their function is: ("Extension is the other part of our name, Extension, indicates what we do. We extend research-based information from the University of California, other universities, and federal agencies, as well as our own local applied research.").

    Here is a link that might be useful: most recent California Davis Extension Service recommendation

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    Please notice that the extension article cited earlier did not say RMV, it said rose viruses. I feel that attempts to limit the discussion to one or a few viruses (which even cannot be justified by the literature) is missing my point that rose gardeners should be informed that a rose virus may appear in their rose beds that is not there because of the fault of the seller.
    A quote from the link below: "Purchasing virus indexed (VID) stock GREATLY enhances the likelihood that you will get disease-free roses. It is not, however, an absolute guarantee. I'm not the only one to have purchased a VID selection of a certain hard-to-find rose, only to see those unmistakable signs of virus appear as the rose matured. The article Diane linked above encourages customers to quiz vendors about the VID status of their stock. That's certainly a fine thing to do. Just be aware, though, that the answers and/or evasions you're likely to elicit, even from some highly reputable vendors, may serve only to increase your frustration. Most small rose businesses do their best to acquire healthy stock, but few (if any) of them have the resources to have those highly technical & fairly costly lab tests performed on each variety they sell."
    http://forums2.gardenweb.com/forums/load/roses/msg022235431402.html
    --------------------------------
    Back to a discussion of the following statement: "Notice in the last HK post that all of the citations on slow spread in the field are from the 1980s. It's been nearly 30 years, folks! In all that time, any such "suspicions" have been laid to rest -- still NOT ONE INCIDENCE of spread in the field has EVER been demonstrated."
    Posted by henry_kuska z5 OH (kuska@neo.rr.com) on Fri, Feb 5, 10 at 18:05

    If one is interested in old garden roses, then one should be aware that another rose virus (rose leaf curl) may be a problem.
    "In the United States, the infectious agent of rose leaf curl occurs in many �antique" roses in community rose gardens. The disease is widely distributed in the United States, but when it is seen in hybrid tea roses in public gardens, "antique" roses are usually nearby."

    http://web.aces.uiuc.edu/vista/pdf_pubs/632.pdf

    Is it still considered a problem? The following is from a March 2009 University of California paper:

    "Infected rose plants. Slow natural spread."

    http://www.ipm.ucdavis.edu/PMG/r280112611.html
    ---------------------------------------------------
    Please notice the statement: "The disease is WIDELY DISTRIBUTED in the United States," and compare that to the earlier statement: ""As used by gardeners," rose mosaic in the USA is well more than 99% PNRSV, substantially less than 1% ApMV, and so exceedingly much less than 1% all other viruses combined as to be completely ignorable and irrelevant."
    -----------------------------
    Please notice that the extension article cited earlier did not say RMV, it said rose viruses. I feel that attempts to limit the discussion to one or a few viruses (which even cannot be justified by the literature) is missing my point that rose gardeners should be informed that a rose virus may appear in their rose beds that is not there because of the fault of the seller. As indicated by the above this appears to be particularly important for those interested in antique roses. ("The disease is widely distributed in the United States, but when it is seen in hybrid tea roses in public gardens, "antique" roses are usually nearby.")

  • trospero
    12 years ago
    last modified: 9 years ago

    Malcolm, can I offer you a martini??!

    I would like to draw attention to a statement Kim made in this discussion, regarding the importation of roses from the UK and the infection status of those plant materials.

    What Kim said is quite accurate: many of the OGRs that were in commerce in the UK from the late 1960s onward had been imported to the UK from the US, from sources that are well known to have been the primary source of virus infected roses in the US. (in that era of commercial rose production) Any US nurseries that claim their roses are virus free just because they have imported plant material from non-US sources, is spouting misleading marketing rhetoric and nothing more. If you choose to believe that kind of statement, that is your choice, but in no way does it represent some kind of infallibility or superiority of stock offered by that nursery. Caveat emptor, and all that....

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Well, as I said before, it's truly hopeless. Just hoping thinking readers will realize where the lunacy lies, here. Interestingly, when the public asks Davis for advice concerning rose mosaic, they often refer them to what I've written (personal communication from them -- Yes I know, all "real" scientists lie every time they give a personal communication). I've also had many discussions with the folks at Davis, and yes, they and we agree utterly, absolutely, on every aspect of rose mosaic.

    Whatever hooey is referred to above, no, no spread in cold climates has ever been demonstrated, nor is there any reason at all to think that it might be spreading.

    Davis deals with many viruses on many crops. True, some are equipment-spread. The viruses causing rose mosaic are not among those.

    Since virtually all of the "virus" that American rose growers are interested in is rose mosaic or rose rosette, yes, there is indeed good reason to limit this discussion to mosaic, since that was the original purpose of the thread.

    As always, the goal here seems never to be truly educated; rather it is blather and obfuscation, over and over and over and over and over again. It never ends. Yet nothing useful ever comes of it. It just makes people annoyed (and they should be annoyed!). What a waste of time.

  • jaxondel
    12 years ago
    last modified: 9 years ago

    Malcolm -- It's been said that the only good thing about beating one's head against a wall is that it feels so good when one stops.

    We can do nothing to guarantee world peace, or save the planet from the loonies who are convinced that humanity is duty-bound to despoil the environment UTTERLY before the prophesied arrival of the rapturous end of days. Ergo, why be dumbfounded that some choose to obsess over RMV and ignore the science that you have so patiently & so astutely attempted to convey?

    At your request, here's an altogether appropriate coda to this impossible exchange . . .

    Here is a link that might be useful: This Song's For You

  • grandmothers_rose z6b
    12 years ago
    last modified: 9 years ago

    Oh, I was so waiting for someone to post that music! Thanks jaxondel! Love the comment about heads and walls, too.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    One of the cited scientists in the ARS paper is "Charlene Harwood,Bear Creek Nurseries."
    -------------------------------------
    She was the Ph.D that was in charge of the J&P virus cleaning program.

    The reader may find this of interest:
    "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. Please read the following link to put in context:
    http://www.rosehybridizers.org/forum/message.php?topid=31712#31864

    Please note: "they found, even when grown in "sealed greenhouses with no possibility of spread, the viruses spontaneously regenerated"

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

  • roseseek
    12 years ago
    last modified: 9 years ago

    Thank you, Paul. That is a point I have endeavored to make clear for a very long time. Should anyone wish to know WHAT roses we could be talking about, please refer to this archive of availability on HMF. And remember, this only represents less than HALF of the catalogs, hence potential varieties infected and distributed by this source. Anyone obtaining material from this source for sale or production, or providing propagating material from any plants obtained from them, spread the infection further. In those years, it seemingly didn't matter. It's only been less than half the time the issue was identified and known that anything could be done about it. In many cases, they were the ONLY source for the variety. In many cases, only plants originating from them have been the only plants to be found.

    In all the years I sought Fiesta, the striped sport of The Queen Alexandra Rose, I have only encountered three plants. One was grown by a fellow Huntington volunteer, which she purchased from Roses of Yesterday and Today. The second was grown by a gentleman I met while working a Friends of The Huntington Plant Sale, which he purchased from Roses of Yesterday and Today. The final plant is the one Vintage grew, which per page 91 of their Big Catalog (1996), they obtained from Roses of Yesterday and Today. Kim

    Here is a link that might be useful: Historic Archive

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Well that's an interesting (but completely wrong) take on the history at J&P. Unlike "personal communications" from scientists, which tend to be true, what one hears from a corporation trying to save money often varies considerably from the truth. 'Nuff said...

    I do know that J&P's heat therapy system was quite non-standard, and I used to wonder how they could get clean plants out of it -- obviously they couldn't -- no surprises there.

    We'll probably never know for sure what all happened at J&P in those days. What we DO know is that nothing of the sort every happened anywhere else, so what one hears by hearsay is very likely not true.

    As anyone who knows anything at all about virus will tell you, viruses do not "spontaneously regenerate," ever. The concept is ludicrous.

    Jax, I did enjoy the music! Thanks!

  • roseseek
    12 years ago
    last modified: 9 years ago

    Henry, stop it. Attempts have been made to figure out how to find material which may have potential for not being infected with RMV. All of the stuff you have drowned us with, you have previously regurgitated here and elsewhere. Your efforts are not intended to answer the original question, nor to assist in finding solutions.

    Your quotes, including the one above, have been previously been hashed and rehashed and serve no beneficial purpose. Kim

  • trospero
    12 years ago
    last modified: 9 years ago

    "the viruses spontaneously regenerated"

    Baloney. Absolute baloney. I have had sufficient personal interaction with J&P representatives to know that no statements on their so-called "clean up" program can be believed.

  • rosefolly
    12 years ago
    last modified: 9 years ago

    Threads now run to 150 messages.

  • harborrose_pnw
    12 years ago
    last modified: 9 years ago

    Thanks so much for the input on the comment by Heirloom that its roses are virus free. I'd thought it was a rather bold statement and have been curious about it.

    Kim, I looked up that quote in the Jack Harkness book and thought I'd write it out as it's quite interesting. One thing that finally makes sense to me now from reading it is why any cuttings taken from the plant will have RMV. This has been very interesting reading, thanks. I have just blinked hard as I scrolled down.

    from "Roses" by Jack Harkness

    The 1950s marked the greatest dominance which American rose breeders had ever known; I have tried to pick out the most significant Hybrid Teas of the decade, and about half of them come from the United States. Perhaps I should add here that the American growers gave us free with their roses the unwanted gift of a virus called rose mosaic, which they knew perfectly well inhabited pretty well their entire stocks. Their view was that it appeared to have no detrimental effects on the roses, and was therefore not worth worrying about; indeed some went so far as to advance the possibility that might be beneficial. This mosaic may be recognized as yellow tracery upon the leaves, and it always adopts a symmetrical pattern, and may thereby be identified. It is most likely to be seen in very hot weather; although if it cannot be seen, one should not conclude that it is absent. It lies within, latent, ready to do its stuff when conditions invite, just like countless other organisms which inhabit living bodies, including yours and mine. It lives in the sap of the plant, and may be transmitted by intrusions of the sap, which occur mainly through the bites of insects or the tools of the rose growers. The great means of transference in America was through the roots they grew their roses on. In Europe, these were supplied by rootstocks grown from seed, through which mosaic is rarely passed. But in America, they grew them from cuttings, and once the stocks from which cuttings were taken were infected, then every rose granted on them was infected too. After much complaint from Europe, the Americans began some cleaning up, but I don't know that they have much heart in it. Well, when you consider that every plant of 'Queen Elizabeth' most probably has rose mosaic, you can understand their skepticism. p. 102-103

    and from comments about 'Queen Elizabeth' p. 124, just to make sense of the last sentence above, "Looking back through the years of my life as a rose grower, I think this is the best rose raised during that time. Its vigour ensures easy growth and good performance..."

  • roseseek
    12 years ago
    last modified: 9 years ago

    Thank you Gean! Sorry for mis-remembering it a bit, but I did remember it was there. Great book, isn't it? Kim

  • harborrose_pnw
    12 years ago
    last modified: 9 years ago

    Kim, it is a book I am very glad to own and have you to thank for recommending it to me! :)

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following was stated: "Your quotes, including the one above, have been previously been hashed and rehashed and serve no beneficial purpose. Kim"
    -----------------------------------
    H.Kuska comment. Kim please provide a link(s) for where my last quote has been hashed and rehashed. Also, was that quote one that you made? I assume that that thread is still open. Are you going to retract it?
    Are you also going to retract your part of the following:
    "Posted by Jim Sproul (zone 9) [email] on Wed, Nov 10, 2010
    Hi Henry,

    Asking questions and seeking the answers are marks of a good scientist. I think that you have done an excellent job scouring the literature to find information to help answer the questions that you pose. I agree with you that it doesn't all add up yet, that there are still unanswered questions, that the evidence is conflicting.

    My purpose in this discussion is to encourage the enjoyment of rose breeding. I wouldn't want new rose breeders to worry too much about RMV type viruses being an important factor in their new hobby. They haven't been an important obstacle for me over the 20 years that I have been breeding roses (with the exception of my mentioning the instance where some of my seedlings were grafted onto virus infected rootstock by one of the commercial growers).

    I understand that there may be different experiences among northern rose breeders, but even then, I suspect that the absolute effect of RMV type viruses on a breeding program would be small. You are right that the question has not been answered. It would be interesting to conduct controlled experiments to get a better handle on the degree to which the rose immune system is challenged by cooler climates, and whether there is a greater impact there with respect to RMV type viruses.

    Jim Sproul

    ----------------------------------------------------------
    Re: Yellow Queen Elizabeth
    Posted by Kim Rupert [email] on Wed, Nov 10, 2010
    Yes, I join Jim in thanking you for sharing such a great breadth of information and research, Henry. While many questions do remain unsatisfied, many others now make a whole lot more sense. Thank you! "
    ===============================================
    The following was stated: "As anyone who knows anything at all about virus will tell you, viruses do not "spontaneously regenerate," ever. The concept is ludicrous."
    -----------------------------------
    H.Kuska comment: Please notice the use of the word "EVER" and compare it to the following reviewed published scientific statement: "Temperature sensitive mutants that have the same mutation in the same gene will for example not be able to complement each other. It is important to distinguish complementation reactivation where a higher dose of inactivated mutants will be reactivated and infect a cell because these inactivated viruses cooperate in a poorly understood process. This reactivation probably involves both a complementation step that allows defective viruses to replicate and a recombination step resulting in new genotypes and sometimes regeneration of the wild type."
    http://science.jrank.org/pages/7190/Viral-Genetics.html
    ---------------------------------
    H. Kuska comment: I do not think that actual regeneration was what J&P is referring to, I feel that it was what I gave a quote (and link for) for on Fri, Jan 13, 12 at 11:58. "that virus levels may be temporarily reduced below the level of detection resulting in a negative virus test, but after some time (several weeks), as the plant matures, virus levels return to normal allowing a positive test result.
    ==================================
    Concerning the following quote: "What we DO know is that nothing of the sort every happened anywhere else, so what one hears by hearsay is very likely not true."
    H.Kuska comment. I have given the links to 2 statements stating that they were told by California, Davis that it happened.
    "The following statement was made in 1988: "Well, Malcolm, then you had better speak with the folks at Davis!
    Because some years ago they reported to the group at the inaugural meeting of a California rose plant grower's association meeting at Davis that virus DID in fact spontaneously reappear. AND said plants were in an screened, isolated green house, to boot!
    I know what I heard that day at Davis, and other people in that audience heard it, too."
    http://groups.google.com/group/rec.gardens.roses/msg/61458eaadecee942?dmode=source
    AND
    "The following link contains the following 2005 statement: " I've had the opportunity to attend a couple of the GRC meetings, including one where various RMV's were discussed. I think that the reference to "supposedly clean blocks" was made in a discussion of varieties that had been heat treated. They were surprised to see virus infected plants showing up again after they had been indexed at Davis."
    http://www.rosehybridizers.org/forum/message.php?topid=5948#6012


    Here is a link that might be useful: My link on return of virus information

  • jon_in_wessex
    12 years ago
    last modified: 9 years ago

    Same old gossip so I'll repeat my mantra of the last 12 years: Never seen a case of RMV in any OGR in any garden or collection in the UK. Never heard a report of any such sighting - even from dear American rosarian visitors over many decades. One would assume that had virused budwood from California been imported to the UK, propagated here and distributed widely across the UK and Europe, Australia, South Africa, New Zealand, etc through OGR nurseries, then those plants - even down to today's descendants - would be virused, and even the dim-witted foreigners might have noticed and reported same.

    Apparently the Lester/Tillotson virus is so stealthy that it lies completely hidden until it hears an American accent and knows it has come home - an early form of bio-terrorism?

    We have enough pathogens of our own, and any responsible nurseryman would follow Harkness in roguing-out and destroying weak or diseased material before it got to market. Harkness's remarks were specific to the American-raised HT's of the 1950's. Most of which I am delighted to have seen the back of:)

    I would be glad to see *factual* information - not the usual gossip from the same old sources (who, as far as I know, have never visited English rose gardens themselves) - on what varieties of OGR's are said to have taken this route. To say 'all of them' is patently ridiculous. By far the greatest proportion of OGR's imported into the US from Europe (and that obviously includes almost all varieties) did not originate from Californian stock.

    On a related matter of interest to me - some years ago the collection with which I am associated sent budwood (gratis) of a great many OGR varieties to the group responsible for the start-up of the San Jose Heritage Rose Garden. The propagation from that material was carried out by Tom L, who has since - and frequently - been lambasted by rosarians on this forum for selling virused material. Does this mean that all the OGR's supplied to the Heritage are virused? And all those distributed from there to the majority of well-known OGR nurseries/collections in the US? And which of them were already virused from their earlier trans-Atlantic voyages? And why are those varieties clean elsewhere in the World?

    *Just the facts* please, gentlemen! The rose world is too full of under-researched, hurtful and damaging 'apocrypha'.

    Best wishes
    Jon

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Jon, I've not yet found a rose that went through the RYT nursery that was not infected with that same characteristic strain of PNRSV. I don't know when they first acquired the virus -- it's entirely possible that they were in business for quite a while before that happened. So perhaps some of their earlier releases were clean.

    In thinking about mosaic in Europe -- I've seen quite a lot of it at Kew, but as I recall, that was always on modern HT/G/F classes of roses. I can't recall ever seeing it on an OGR. I do believe that most of Europe's own roses remain clean.

    And in some defense of Heirloom, in addition to importing their stock, it was my understanding (from direct correspondence with John Clements) that he was having the entire collection indexed by Washington State's ELISA lab. I don't know that that got completed before John's passing, but he had the concept anyway.

    And HK again brings out the old "H.Kuska comment. I have given the links to 2 statements stating that they were told by California, Davis that it happened.
    "The following statement was made in 1988: "Well, Malcolm, then you had better speak with the folks at Davis!
    Because some years ago they reported to the group at the inaugural meeting of a California rose plant grower's association meeting at Davis that virus DID in fact spontaneously reappear. AND said plants were in an screened, isolated green house, to boot!
    I know what I heard that day at Davis, and other people in that audience heard it, too."
    http://groups.google.com/group/rec.gardens.roses/msg/61458eaadecee942?dmode=source
    AND
    "The following link contains the following 2005 statement: " I've had the opportunity to attend a couple of the GRC meetings, including one where various RMV's were discussed. I think that the reference to "supposedly clean blocks" was made in a discussion of varieties that had been heat treated. They were surprised to see virus infected plants showing up again after they had been indexed at Davis."
    http://www.rosehybridizers.org/forum/message.php?topid=5948#6012 "

    So I must again point out that after that, I talked with the head of FPMS Davis as well as their main field manager, both of whom were unfamiliar with those statements, but assured me that they most definitely were NOT true, that they had never seen any such thing, and someone (perhaps their own spokesman at some meeting) had their "facts" wrong. Notice again, that was 24 years ago. One would think that if those "facts" were correct, someone would have noticed. But what we have here is mistaken hearsay from a meeting, not, as HK would normally demand, a peer-reviewed published paper. It is not true, FPMS Davis themselves say it is not true, and there is no documented record of it. As for the 2005 comment "I think that the reference to "supposedly clean blocks" -- how iffy and hearsay can you get? Again, FPMS themselves say is not a true statement.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    "ann peck
    Re: Mosaic virus or what?
    July 17, 2011
    A problem with Elisa is that it's visual and it can only identify viruses that are in plants with a high titer of virus.

    The coming thing in plant pathology is virus extraction and then replication and the resulting material is sequenced and compared with known primers. (The work done to isolate the Rose Rosette virus give detailed descriptions of the procedures; they're in Alma Lacey's M.S. work.

    This sort of approach is far more definitive that Elisa tests; it's also how Rose Spring Dwarf was isolated and described.

    I don't know who's doing comparable virus work in Europe. Kaminska and his collegues in eastern Europe have done similar work on phytoplasmas in roses (in Glass House roses in Europe) as well as in many other plants."

    http://www.rosebreeders.org/forum/read.php?2,37093,37093#msg-37093
    ---------------------------------------
    Also please read carefully the statement that I posted on Wed, Feb 15, 12 at 0:38 by Dr. Zlesak, one of the scientists that is doing Rose Virus research.
    " "This is a very interesting line of thought. Elisa isn't always that accurate depending on ones threshold for color (background color can vary depending on things inherently in the rose tissue which can be partly cultivar dependant) and how concentrated the virus is."
    ---------------------------------------
    I would like to blacken "HOW CONCENTRATED THE VIRUS IS".
    ==========================================
    Help-ME-Find has a rose virus link to a New Mexico State report that is no longer active. I recommend that it be replaced with the California Extension Service report or possibly it and Dr. Zlesak's concluding paragraph:

    "In the meantime I think, if possible, we should remove plants with obvious signs of infection and try to use good sanitation and pruning practices."

    http://www.rosebreeders.org/forum/read.php?2,14137
    ========================================

  • trospero
    12 years ago
    last modified: 9 years ago

    "Threads now run to 150 messages."

    Which means we are close to done with this, thankfully.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    The following link is from Paul Barden's web page.

    Here is a link that might be useful: link referred to above

  • rosefolly
    12 years ago
    last modified: 9 years ago

    In reference to Tom L -- I seem to remember that he had plants budded by a third party vendor, and discovered to his dismay that all the rootstock they used was diseased. It was a bad year for him. In that case, healthy budwood became contaminated by the rootstock. Could that have been the budwood you are describing, Jon? I had no idea that it was such valuable material. This would have been sometime in the early 1990s when I was still fairly new to old roses. Perhaps someone else who was active then could remember the details more clearly. It was much discussed here on this forum before mention of Mr L's name was banned on GW and he became known as the Unmentionable Rose Grower.

  • mad_gallica (z5 Eastern NY)
    12 years ago
    last modified: 9 years ago

    Since Harkness (and now Jon) both say that virused roses started showing up in Europe in the 1950's, isn't that when the bulk of the American production was being budded onto selected multiflora? Not seedling multiflora, but carefully developed clones. Somewhere in the old ARS Annuals upstairs there are articles on the best rootstock, and those are always the top rated ones.

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Again, ELISA, when properly done, is 100% effective, and has never once, in the 30-ish years we've used it, failed to give an accurate analysis. This is considering the following:

    1. We always enclose "blind" samples of known infected and known uninfected tissue -- blind to the lab -- and unless the results come back with them correctly identifying all of those, we would not believe their results on our unknowns. That assures that virus titer is in a usable range on the day the test was done. In actual fact, in all those years, they (WSU Prosser's ELISA lab) have NEVER gotten one wrong, even once. Pretty good record.

    2. Once that's done and a rose is "certified" clean (notice that ELISA is just one of the tripod of tests we run -- they're also tested with 'Mme. Butterfly' and 'Shirofugen' cherry -- all 3 must come out unambiguously clean) -- no rose once certified in that way has EVER later been found to have rose mosaic. Not one. Not ever. Not even in cold climates where all the intelligent people live. On rare occasions, the lab has said a test was somewhat ambiguous, and in those cases, we ignored all of the results from that run, and re-ran them later.

    3. While we use the three tests for redundancy, we've never seen a case in which one test came out positive while the others came out negative -- in 100% of the roses I've ever tested, all three methods have agreed on their result.

    So obviously, the point of this long, drawn-out discussion with all kinds of complaints, is moot -- there is no problem here. We have no problem at all identifying where the disease is. No evidence to the contrary has been presented here.

    I would like to say that you can't argue with absolute 100% success, but obviously, there is one person who is determined to argue continuously with absolute 100% success! So yes, I'm just working our way toward the 150 posts mark, and hoping to keep us focused on the real issues, rather than being constantly drawn into perfectly silly little side arguments that are in and of themselves without merit.

  • henry_kuska
    12 years ago
    last modified: 9 years ago

    If you have decided to disinfect your pruners, the following link from Washington State University may help get you started.

    "To disinfect your tools or not - what's the bottom line? To make an informed decision, you need to know your pathogen and its life history, and use common sense:

    ♦ if it's a virus or viroid, disinfect your tools."

    .......

    ♦ if you are pruning irreplaceable plants, disinfect your tools."

    Here is a link that might be useful: pruning plants fact sheet

  • trospero
    12 years ago
    last modified: 9 years ago

    "To disinfect your tools or not - what's the bottom line? To make an informed decision, you need to know your pathogen and its life history, and use common sense:

    ♦ if it's a virus or viroid, disinfect your tools."

    At no point in the Chalker-Scott article cited (pruning plants fact sheet) does the author speak about rose virus/RMV/PNRSV. And yet we know that some viruses have been demonstrated to be transmissible by cutting tools, while others are not (or the infection rate is extremely low/negligible) So why cite an article that isn't speaking to the issue of RMV transmission? It isn't relevant.

  • jerijen
    12 years ago
    last modified: 9 years ago

    Jon -- Re. the Heritage.
    I actually asked that question. The answer was that the roses planted in the Heritage were NOT grown with Mr. L's commercial stock, and they were planted on VI Huey rootstock.

    Jeri -- Who gets curious, sometimes, and asks.

  • jon_in_wessex
    12 years ago
    last modified: 9 years ago

    Thanks, Jeri - that's good to know.

    Best wishes,
    Jon

  • malcolm_manners
    12 years ago
    last modified: 9 years ago

    Again there is not the vaguest evidence for tool-spread of rose mosaic. PNRSV and ApMV are very fragile viruses and not at all easy to spread. Even when grafted, it takes about 3 days for the virus to begin to move from the infected side of the new graft to the uninfected side -- after mitoses have begun and a callus bridge has begun to form. Until then, even intimate tissue-to-tissue contact does not result in spread.