I have a question I hope one of our experts can answer.

Every article on RRD mentions the role multiflora wild roses play in spreading the disease--because multiflora is so susceptible.

A lot of us buy roses from Palatine which uses multiflora rootstock for most of its roses.

Does that mean our Palatine roses will be more susceptible to RRD?

Thank you for any information on this issue.

Kate

Another new article:

http://www.gardenatoz.com/what's-up!/tip-cuttings/rose-rosette-disease/

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

Kate, the short answer to your question is "No". A rose growing on multiflora rootstock is no more susceptible to RRD than any other rose in your garden. The thing with multiflora (and, now, Knock Out) is that there is so much of it growing out there ... multiflora in the wild, and large beds of Knock Out in just about every commercial landscape. The mites that can transmit the disease have more concentration of places to drop from the wind and become infected. When these mites pick up their breeze and move on, the disease can spread to wherever they land next (multiflora, Knock Out, or our gardens). If the rootstock stays underground like it's supposed to, the mites can't land on it.

Thank you for the information, hartwood. So glad there is not another thing for me to worry about. : )

Kate

I was wondering this too. There was a bit of a torch and pitchfork party a while back disparaging the government's promotion of multiflora back early in the 20th century as good erosion control. I got the impression from that- that it WAS multiflora that was causing the disease. Otherwise, why blame wild roses for catching something anybody can get it?
So- is this determined to not be a multiflora disease? I know the mite carries it, but then the virus becomes an infection. Is this infection not predisposed to any kind of rose?
Please do not think I am asking these questions as though I think you are mistaken. I think you are probably right. But I don't know. And the discourse before really blamed the multiflora.

The next question- wouldn't rose growers (large operations) in highly impacted RRD areas be expected at some point to get the disease? RRD infections can probably happen anywhere along the chain to the garden center-- but I am wondering if it is prudent to consider adding roses from badly infected areas??
Some states have strict AG import rules to stem these kinds of tides.....

I would consider Hartwood's answer a "first approximation" but for all practical purposes probably correct answer in this case. However, in general, rootstocks may/do have effects on the plants budded to them. The link below is one example.

One has to wonder whether rootstocks of native American wild roses that have demostrated an effective immune system against rose rosette virus would at least be effective at slowing down the spread of the disease. This could be a stop gap method until crosses with native American wild roses produce immune commercial garden roses.

Here is a link that might be useful: rootstock effect

The link below appears to be the most complete study so far as to which roses are susceptible to rose rosette virus.

"Rosa setigera, R. virginiana, and R. palustris and the naturalized R. rugosa seem to be very resistant to possibly immune to the disease."

See:

http://www.mdinvasivesp.org/archived_invaders/archived_invaders_2011_07.html

Here is a link that might be useful: July 6, 2011 Maryland Department of Agriculture (MDA)

This 2012 article appears to give further support to the idea of fighting rose rosette virus by using resistant understocks:

http://hortsci.ashspublications.org/content/47/2/164.short

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

Someone in the article states that you don't have to worry about the mites infecting other plants but I wonder if that has really been established. The name of the mite is Phyllocoptes fructiphilus, which sounds like it likes fruit.
I just wonder if the mite sometimes eats and lives on other plants but doesn't cause symptoms on them. It was interesting to hear the recommendation of using horticultural oil. I was thinking that that might be a good dormant season treatment as it would smother mites and eggs and would not cause the mites to build up resistance. Kim R was thinking the same thing. It would also be much less toxic, though still a hazard to breathe I think.

Somewhere else in the article it was said that RRD has been steadily spreading from west to east, which got it backwards I think. I have heard conflicting information about whether pruners spread RRD. Seems like we're still in the information gathering stage .

This link is to a rose rosette video:

http://www.youtube.com/watch?v=SNGBh-l2PHg

Here is a link that might be useful: link to video

This recent article by scientists at the Department of Plant, Soil, and Entomological Sciences, P.O. Box 442339, University of Idaho, Moscow, ID 83844-2339, USA suggests that when an insect vector is involved the science may be more complex that most of us would have expected.

"We show that the aphid Rhopalosiphum padi, after acquiring Barley yellow dwarf virus (BYDV) during in vitro feeding, prefers noninfected wheat plants, while noninfective aphids also fed in vitro prefer BYDV-infected plants."

This suggests that it may be possible to infect roses with a weakened form of rose rosette virus whose presence would discourage mites infected with the full blown virus from feeding on the "vaccinated" roses.

Here is a link that might be useful: link for recent research paper

Ahh, Henry. You are of fount of the joy of growing roses. Keep spreading the word until the ARS takes its last breath.

Thanks for the info Henry.

I spent another two hours today pulling out and destroying more rose bushes due to RRD.

I hope there is an easy and economical solution soon in regards to controlling and hopefully eradicationg RRD.

It would be nice if they could come up with a vaccine. I was reading about horticultural oil yesterday and it did say it was effective against eriophid mites. It might not help much, since mites can still blow in from afar, but it could help some. One time Ann Peck recommended spraying a plant with hairspray to immobilize mites before removing a sick plant. But horticultural oil might have the same effect. I think it might be worthwhile for researchers to test things that make plants taste terrible to mites, like cayenne pepper. You'd need a microscope to see whether they avoid pepper sprayed plants.

In another thread (that started with mildew but also covered Japenese Beetles and Rose Rosette Virus) I suggested trying silicate applications to the soil.

Here is a link that might be useful: thread mentioned above

Sounds like it's worth a try and might deter several pests at once.

These "New" articles give versions of already known facts. As I read them, I find nothing "New," Just repeats.
I read the same stuff in Ann Peck's web book on RRD several years ago.
It appears nothing "New" has been found about RRD, Just rehashed.
Regarding R. rugosa seeming to be very resistant to or possibly immune to the disease, not in my yard. Rugosas get it as often as other roses.
Until someone comes up with something really new that might cure or prevent it, don't get your hopes up!

Since rugosas are not native North American roses, it was a surprise to me to see it on the list (I would of thought that it was not exposed to the virus long enough to develop an immunity). I wondered if the mites were not able to recognize, from the leaf texture, that rugosas were roses.

It is also possible that rugosas reported to be infected by the general public were actually suffering from herbicide damage since an actual test was not available. I do not have the details on how Maryland determined that rugoses were: "seem to be very resistant to possibly immune to the disease." Now that an actual test has been developed, hopefully, someone will conduct controlled tests to check the Maryland report.

Is the American Rose Society funding any rose rosette research?

The ARS is funding a three year study at the University of Tennessee. Objectives include trying to develop an ELISA test and studying the spread within garden conditions of a garden composed solely of a single cultivar (way out in the country where there are no rose gardens down wind). They have as RRD source plants severely infected plants of the same cultivar.

I haven't heard the results of the first year, yet.

-----------------
re R. rugosa.

Early on, in the garden we followed at Lincoln Memorial University, there was also a plantings of many Pink Grootendorsts near a building that had been the Dairy. They did not get sick for several years as the modern roses planted immediately downwind of multiflora-rich field whose plants were at least 30%infected with RRD.
At one time we found some strange swellings on the PG canes, and they made the rounds of a number of Plant Pathologists; no idea what their problem was, but it was just the swelling. Then five or six years in, a plant got two canes that were even more thorny, whose new growth spiraled, whose leaf margins were different and whose blooms were messed up badly.

Now I wish I had made scans of the canes, but we were busy with other plases of following the disease as it spread.

The problem with the declarations that certain roses don't get RRD is that no one has ever taken the spectrum of all roses species and planted them in different USDA zones and left them in high disease pressure areas for a five to seven year period.

What I've seen this winter, when where I live is zone 7 low temperatures, is that the plants with RRD have grown through winter....at least the parts with RRD have. The uninfected canes have gone semidormant.

There's so much that we don't know.

Here is a link that might be useful: Rose Rosette E-book

Regarding Pink Grootendorst, Apparently it is a first generation hybrid (sport of R. rugosa rubra � Madame Norbert Levavasseur) so it would not be a definitive test whether the rugosa species itself is immune.
------------------------------------------
MONDAY, FEBRUARY 18
11:45-12:30
A3. Hot Topics on Ornamental Diseases:Boxwood Blight and Rose Rosette**Presenter: Dr. Alan Windham,The University of Tennessee

Here is a link that might be useful: U. of Tennessee Rose Rosette lecture Feb 18

Did anyone watch this?

Webinar: Create A Plan Of Attack For Rose Rosette Disease
Rose rosette disease is poised to have a big impact on your store in 2013. NovaFlora's Michael Dobres will address simple prevention measures that can help reduce or eliminate the incidence of this disease in this webinar on February 13.

Here is a link that might be useful: create-a-plan-of-attack-for-rose-rosette-disease

One report so far on the Webinar.

http://www.rosebreeders.org/forum/read.php?2,50305,50307,page=1#msg-50307

Here is a link that might be useful: link for report on Webinar

"Hi Henry,
You will receive an email in about a week when the recorded version of the webinar is posted."

Today David Zlesak has posted the links to the Conard-Pyle rose rosette webinar in a thread on this subject.

http://www.rosebreeders.org/forum/read.php?2,50305

Here is a link that might be useful: Rose Hybridizers thread on webinar