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henry_kuska

plant-experts-say-thousands-of-roses-will-die

henry_kuska
10 years ago

Does anyone have any first hand knowledge about this?

See:

http://www.kjrh.com/dpp/news/local_news/fatal-virus-strikes-tulsa-rose-garden-plant-experts-say-thousands-of-roses-will-die

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

Comments (22)

  • seil zone 6b MI
    10 years ago

    Scary to think of losing an entire garden like that but I suppose it is very possible.

  • jim1961 / Central Pennsylvania / Zone 6
    10 years ago

    Yes its scary as roses may be doomed someday if this becomes like a epidemic of sorts...

  • deervssteve
    10 years ago

    I don't know how many posters here have been severely impacted by this disease.

    What I have noticed is that the media likes scary stories.
    In California there is a disease called sudden oak death which has killed a lot of oak trees in California. Our yard has a lot of mature oaks. My wife freaked out over this news. The disease will likely be limited by the climate and we are probably ok. The disease attacks live oaks.
    Most of the larger oaks are in are yard are Valley Oaks which don't get the disease.We do have a lot of live oaks and we regularly have an arborist inspect are trees.

    So when I read these stories I wonder how much the threat is inflated by the media.

  • henry_kuska
    Original Author
    10 years ago

    With such a large "possible" loss, I hope that they utilized the PCR test on at least one bush.

  • anntn6b
    10 years ago

    Henry, they are right next to Arkansas where the PCR work has been done. Dr. Rose Gergerich has tracked RRD throughout Arkansas.

  • henry_kuska
    Original Author
    10 years ago

    anntn6b, my point was that this specific "possible outbreak" should be checked by PCR.

    If a rosarian discovers one suspect rose, he/she probably would not pay the $25 (or whatever the cost is now) to have it checked by PCR. But, in this case with "thousands" of roses in question, a PCR test seems (to me) to be a logical step to make sure this is actually a virus outbreak and not a herbicide/other cause problem. (As has been pointed out in an earlier thread even mulch can be contaminated by herbicide/ bad chemical).

  • hoovb zone 9 sunset 23
    10 years ago

    Plant experts say this winter they will prune the roses back further than usual and spray special oil to try to kill the mites.

    So this is how "experts" handle RRD?

  • anntn6b
    10 years ago

    Well, one expert is in Gainesville Florida, south of where RRD has been reported by at least a hundred miles.

    I continue to grow roses and RRD has been a bad problem in my part of the country for over a decade. I am not losing even 1% of my roses each year because I rely on garden design to increase air flow, beneficial insects to kill any mites that come in and I don't grow my roses with great amounts of water in the months when RRD spreads most readily. I also keep watch on roses upwind of my gardens to make sure that RRD doesn't get established there.

    I would never smother beneficial insects with hort oil. And I do know that cutting a rose down low isn't going to cure an infection that is already systemic in the rose.

    Listen to people who love roses AND who grow roses. Sometimes we know something worth passing along.

  • henry_kuska
    Original Author
    10 years ago
  • henry_kuska
    Original Author
    10 years ago

    At the spring conferences on rose rosette virus, one of the most important questions (in my mind) that was brought up was how long does it take for a single stem infection near a cane tip to reach the lowest part of that cane. This would probably vary with temperature and variety of rose (how effective is that varieties' immune system); but it would be helpful, when deciding whether to remove the bush or to cut the cane to the ground, to have a rough approximation of the travel time. Does anyone know if anything has since been determined on this question?

  • kentucky_rose zone 6
    10 years ago

    Ann,
    What is the purpose of not watering a lot during the months that RRD spreads? Pierrine was the only rose that I lost this year to RRD. I was surprised since it wasn't tall/big bush.
    Thanks,
    Hattie

  • anntn6b
    10 years ago

    Hattie, to keep succulent new growth to a minimum. The year that we irrigated religiously through a bad drought was the year we lost 5% of our garden. The thought (which I've shared with Amrine and Tazenakis and they agreed) was that mites migrate from their wild rose habitats in search of more succulent growth, and that's why we see worse infections in dry summers happening in well watered gardens.

    Henry, your question was asked at the meeting and the only person who had anything to contribute was me. I have watched the disease move down one side of a multiflora cane and (that I cut off and moved into my rose-less kitchen) it was taking 7-10 days for new symptoms to emerge on the next leaf axil down. This happened several times.

    Half the folks there had never seen Rose Rosette. Most had never observed it in the field.

    You know I have talked here before about cutting off canes with single site symptoms way out on canes. That stopped infections on Charles Austin, Rouletti, American Pillar, Fortuniana (last fall), Tausendschoen, to name a few, but I never could save a Hybrid Tea.

    Some of those were spring saves, some were fall.

    There's not much literature out there about the effectiveness of vascular systems in different classes of roses.

  • kittymoonbeam
    10 years ago

    I think it's wonderful that you have found a way to keep your roses alive when this disease is all around. If you can do it, others can too. I'm sorry you have to battle it at all.

  • henry_kuska
    Original Author
    10 years ago
  • nastarana
    10 years ago

    Which beneficial insects prey on the mites?

  • anntn6b
    10 years ago

    There are predaceous thrips that feast on both thrips and eriophyid mites. There are other mites that eat them.

    The early Staplin, et. al. paper from Nebraska describing witches' broom of rose talked about the problems they had in isolation booths growing roses with the vector mites (P. fructiphilus) on the roses. Problem was, the roses kept getting infestations of spider mites and the spider mites kept wiping out the eriophyid mites (P. fructiphilus.)

  • henry_kuska
    Original Author
    10 years ago
  • dan_keil_cr Keil
    10 years ago

    In 5 years I've lost three minis, two in the last two years.
    I was called to look at some Knockout roses at a elderly complex. I saw RRD on about 15 plants.
    Our Rose Society was at the University Of Illinois Gardens.
    A couple of our members saw some roses. They were Knockouts and they were infected bad. The whole planting of about 50 bushes needed to be removed

  • windeaux
    10 years ago

    Steve's comments about the threat to oak trees in CA and the attendant media hoopla reminds me of the untold millions of elm trees of fond, and fairly recent, memory. In the desert southwest those trees were planted by the tens of thousands during the 1940s. They thrived in a tough environment -- turning towns throughout the region into oases of spring and summer green surrounded by vast and inhospitable expanses of dry, scrubland shaded brown, tan, sandy red.

    When word of Dutch elm disease began to filter in from various parts of the country, we blithely assumed that our remoteness would insulate us and our trees from the scourge. Then in the 70s, those trees (elms, BTW, have a life expectancy 150-300 years) began to decline -- a few at first, then a lot more, finally ALL of them. Every single one of them. The decline was inexorable, and the trees' demise was fairly swift.

    I don't know where kids there go to play in the shade these days. Next to buildings, I guess. I'm fortunate that my elm-shaded childhood was lived before all the media hype about dutch elm disease became cruel reality.

    Its happened before. Living now the eastern U.S., I occasionally encounter people who still mourn the American chestnut tree. It once made up 25% of eastern forests. Now there are virtually none. Mature American chestnuts were truly majestic trees . . . or so I'm told.

  • henry_kuska
    Original Author
    10 years ago

    dan_keil posted about the same information in another thread. I then asked: "Dan, how did you rule out herbicide damage? "

    I am serious as both nursing homes and public gardens often employ groundcrews which are used to using herbicides for weed control in both the surrounding lawns and even in the flower beds. There is a PCR test available. I recommend that if rosarians see what looks like widespread rose rosette virus damage, they inform the caretaker of the 2 possibilities and suggest the PCR test. (One doesn't have to suggest immediate removal, since we are talking about the case of already widespread symptoms).

  • Maryl (Okla. Zone 7a)
    10 years ago

    It's been my experience (unfortunate as it is) that the difference in spray drift from Herbicides and RRD can often be differentiated by the amount of initial damage exhibited. If one lone cane (or a small part thereof) is deformed I usually think RRD. If more then one cane seems to be affected I think of the possibility of Herbicide damage. The next test (although a bit risky) is easy. Cut back the offending cane (canes) and if new growth sprouts with symptomatic foliage it's RRD.....Interestingly enough, I took out an Austin rose this spring that exhibited RRD growth. Further confirmation of its RRD appeared 2 months later when a leftover piece of the root sprouted showing RRD symptoms on even the tiny new leaves. I will not replant in this spot for a couple of years just for this reason - unseen leftover virus infected roots........The plight of the elm tree in America I hope isn't indicative of where roses will be in 50 years. But if the mite can't be widely controlled (including in the wilds), it may be a sad ending to a glorious hobby........Maryl

  • henry_kuska
    Original Author
    10 years ago

    maryl, not all herbicide damage is spray drift. Herbicide can also be absorbed by the roots.

    Here is a link that might be useful: link to my rose rosette virus web page