The do reproduce in all genotypes we tested. So no mite resistance identified. We did not check site preference.

Professor, are you talking about the SW miniature rose or the large flowered climber?

Thank you for the information about your research in progress.

SW - the climber. Since I am on the subject: we tested the hypothesis of the virus going systemic or symptoms in different areas of the canopy are due to multiple mite infection sites. The results: the virus moves to the roots - pruning is not a viable control strategy.

Thank you. It seems you recently replied to my question about which particular SW rose you are refering to (you said the climber) but the post has been deleted. Should I infer you are not sure which SW this is or was the post deleted accidentally?

I wonder how long it will take for the virus to cross the pond (if it hasn't already done so)..

PS OK thanks, so it is the climber.

The only offspring listed in Help-Me-Find is: Stormy weather X Summer Wind

However no other information was given such as name or hybridizer.

Is there anything 'different' about Stormy Weather's sieve cells?

Maybe of importance are not its offsprings but its parents..

Here's a link with some info

Rosa 'Stormy Weather' is a hardy Climbing Rose with a fast growth habit. Its parents are Heart 'n soul and Rhapsody In Blue, a unique hybrid by hybridizer Pierre Orard (France, 2012).

Jenny's Garden has report of parentage as well as hybridizer

The following was stated: "The results: the virus moves to the roots - pruning is not a viable control strategy."

H.Kuska comment. How long does it take the virus to reach the roots (under all possible conditions such as a rose with partial resistence, high temperate or low temperature, plant in active growth, or rose not in active growth, etc. It is my understanding that the pruning may work if the infection is caught early (and even maybe only at certain times of the year).

We tested for the virus three months after we placed the mites on the plants - We used 'Julia Child' in those experiments.

Interesting. I look forward to learning more as the trials progress.

An easy possible next step would be to graft a susceptibe rose to an understock made from Stormy Weather to see if the Stormy Weather immunity is transferred to the other rose. Apparently in at least one other plant (cherry) this gives the whole plant immunity.

http://www.researchgate.net/profile/Guo-Qing_Song/publication/264831370_Rootstock-to-scion_transfer_of_transgene-derived_small_interfering_RNAs_and_their_effect_on_virus_resistance_in_nontransgenic_sweet_cherry/links/53fb3f4c0cf27c365cf08abf.pdf

We have no evidence that RRV replicates in SW - siRNAs are produced after processing of virus dsRNA, part of the virus replication process.

There are various forms of RNA silencing.

http://onlinelibrary.wiley.com/doi/10.1111/pbi.12353/full

I cannot discuss the details of the proposed mechanisms relative to the present case.

At the layman's level we can say something in Stormy Weather is preventing replication. As was pointed out the virus travels to the roots. In the case of the rootstock being Stormy Weather what will happen? I.E. will Stormy Weather's immune response(s) (whatever it/they is/are) travel to the grafted upper rose and be effective there? To run the actual experiment appears to me to be to be so simple that the possibility should be tested.

"Research suggests that the severity of disease may vary according to the genotype of the rootstock which is grafted with infected scion wood."

http://www.ajevonline.org/content/44/2/148.short

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" To date little is known about the molecular mechanism of this host–pathogen interaction, and about the rootstock effect on citrus response to CTV infection. In this work, the response to CTV infection has been investigated in tolerant and susceptible scion–rootstock combinations by two-dimensional gel electrophoresis (2DE). A total of 125 protein spots have been found to be differently accumulated and/or phosphorylated between the two rootstock combinations. Downregulation in tolerant plants upon CTV infection was detected for proteins involved in reactive oxygen species (ROS) scavenging and defense response, suggesting a probable acclimation response able to minimize the systemic effects of virus infection. Some of these proteins resulted to be modulated also in absence of virus infection, revealing a rootstock effect on scion proteome modulation."

http://onlinelibrary.wiley.com/doi/10.1111/ppl.12395/abstract

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

"These results suggest that RNA silencing was transmitted to non-transgenic tomato and tobacco scions after grafting onto the Sd1 rootstocks and that virus resistance was induced in the scions."

http://link.springer.com/article/10.1007/s13562-015-0334-6

SW was used as the rootstock with infected scion. No infection seen on SW, no virus replication detected. The new growth on the scion still had RR symptoms.

Thank you Professor Tzanetakis. If the combined plant is still alive it would be interesting to see the long range effects (does it lead to death or an equilibrium of milder symptoms).

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

Field experience (one plant) with Stormy Weather.

http://www.rosebreeders.org/forum/viewtopic.php?f=2&t=55260

One question I get a lot: what to do with infected plants. I would cut off the above ground part and apply herbicide onto the crown. This way you avoid spread without having to dig....

I do not recommend the application of Round-Up to the crown due to the possibility of the Round-Up leaving the roots and being absorbed by the roots of nearby roses.

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

If applied at recommended concentrations this is not an issue.

This sounds like an interesting rose to get. Is Stormy Weather available in the US without rose mosaic virus? I see part of the "pipeline" it has gone through here, but I'm wondering if they have taken the time to keep it clear of RMV. As in not grafted it to infected rootstocks?

All SW plants we used were free of mosaic. On that note - There is no such a thing as RMV. Mosaic symptoms may be caused by several viruses none of which is called RMV - Apple mosaic and Prunus necrotic ringspot are the two closely associated with the disease in North America

The following statement was made: " I would cut off the above ground part and apply herbicide onto the crown. This way you avoid spread without having to dig...."

H.Kuska further comment: I strongly recommend not using Round-Up anywhere near a rose bed and in this case definitely not in a rose bed. Rose beds have high organic content and particularly for this discussion high P content. The P competes with Round-Up for soil binding sites. Thus, immobilization of Round-Up, which is the standard explanation for why Round-Up is "safe" when it hits the soil, may not occur sufficiently to protect neighboring plants. In addition to the route of Round-Up reaching the soil by treated plant root "leakage" which I documented earlier in this thread, in this case we also have the problem of what happens to the Round-Up in the dead roots if the dead roots are not removed (as apparently suggested in the above quote). See:

http://www.researchgate.net/profile/Guenter_Neumann2/publication/222401936_Glyphosate_in_the_rhizosphereRole_of_waiting_times_and_different_glyphosate_binding_forms_in_soils_for_phytotoxicity_to_non-target_plants/links/00b7d522733618ea0e000000.pdf

I.E. the Round-Up does not just disappear. It is in your rose bed.

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

The following is a summary of the various Round-Up products (some of which contain additional products that also can "bother" non target plants. You may also find the comments about use when an organic mulch is present (which is very common in rose beds).

" Application over organic mulch

Organic mulches such as hardwood chips and bark are often used in landscapes. Glyphosate becomes tightly bound to soil and organic matter and as such provides no residual control of weeds. In other words, it will only control plants on which it is sprayed. In some cases, however, this tightly bound glyphosate can come off of its binding site and affect the roots of desirable vegetation. This occurs most commonly in a flood situation. For example, if a heavy rain of 2 in. or more occurs after glyphosate has been applied on organic mulch, the glyphosate could move into any standing water in the landscape. This water will then move down through the soil profile and could enter the root zone of the desired vegetation. While the amount of glyphosate in the water will be extremely small, it can cause stunting and yellowing of the growing points of the desired vegetation. Never apply a glyphosate product just prior to a heavy rain. For best results, try to apply when several days of dry weather are expected, and never apply to an area that has standing water."

https://edis.ifas.ufl.edu/hs1171

I read the paper. Before I post my review I have to point out that I have a BS in soil science. Let's look at the main points - two soil types, one sandy at pH 4.5 (which is low even for blueberries) with 0.16% organic matter and 0 exchange capacity and one calcic with 23% CaCO3 at pH:7.6 with good cation exchange capacity. No info on the biological load of the matrix - glyphosate is broken down by the soil flora...

Statistically significant differences if sowing seed immediately after application in both soil types. The other time points with a couple of exceptions show statistically insignificant differences.

I would say that much: Unless you apply roundup onto soiless media and immediately plant roses I would not worry about phytotoxicity. Just make sure you follow the recommended dosage. My approach is (and I have done that in the past) to paint the herbicide onto the crown so there is no drift to other plants.

This is the last time I will come back to the subject. I know there are some interesting ideas out there but I tend to analyze data and make decisions based on concrete scientific data.

Happy 2016...

Regarding the reviewed, published scientific paper I referenced. I feel that it relates to "the problem of what happens to the Round-Up in the dead roots if the dead roots are not removed (as apparently suggested in the above quote)."

The part of the experiment that (I feel) would most apply to the case of painting Round-Up on the crown is the zero time difference data (the neighboring roots are already in the rose bed when the Round-Up is applied).

In the discussion section of the paper the following is stated: "

Toxicity of glyphosate pre-sowing treatments on sunflower

seedlings was also strongly dependent on the mode of glyphosate

application: When glyphosate was sprayed on pre-cultured rye

grass seedlings, detrimental effects on plant growth and the Mn nutritional

status, as well as increased intracellular shikimate

accumulation in the root tissue were more strongly expressed than

after direct soil application of the same amount of glyphosate."

H.Kuska comment: This is the important point of this paper relative to the suggestion of killing the roots and then leaving them in the ground.

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

This is the model that they propose:

"In most plant species, glyphosate is not readily metabolized and is preferentially translocated to young growing tissues of roots and shoots, where it can

accumulate in millimolar concentrations (Reddy et al., 2004;Monsanto,

personal communication). In soil-grown target plants, this

non-homogeneous distribution of glyphosate within the root tissues

may lead to the formation of hot spots of root residues in

soils, containing high levels of glyphosate, which is subsequently

released during microbial degradation of the plant material. Without

a fast immobilization of glyphosate by adsorption on the soil

matrix, glyphosate toxicity to non-target plants may be induced by

root contact with these hot spots. The non-homogeneous distribution

of glyphosate-contaminated plant material in the soil could

also explain the much higher variation of the data on sunflower

biomass production, shikimate accumulation and Mn-nutritional

status after glyphosate application to the rye grass pre-culture as

compared to direct soil application (Fig. 2 but also Tables 1 and 2,

Figs. 3–5). Since toxic effects can be expected only after direct

root contact of the non-target plants with one of the hot spots

of glyphosate-contaminated plant residues, sunflower seedlings

without contact to the hot spots remained unaffected. In contrast,

direct soil application of glyphosate resulted in a homogeneous

distribution and lower bio-availability due to adsorption of the herbicide

over the investigated soil profile."

The readers may find the information in the link below about roundup affecting other roses 3.3 feet away from the treated rose of interest and also the information on the roundup label concerning cut-stump application.

http://forums.gardenweb.com/discussions/1678151/resurrection?n=29

Rose rosette virus acquisition: mites need five days of feeding

Were there any species roses that showed resistance?

No resistance to the mite identified.

I meant resistance to rose rosette virus. Multiple websites, over the years, have mentioned various species showing resistance, and I'm wondering if there were any species roses in your study that actually supported that. I'm curious because I grow numerous species roses, including rather obscure ones. Not that it is obscure, but have you studied R. californica? R. minutifolia is on the rare side, and its foliage looks so different, I'd be interested if that translates into doing better than other roses with more "normal" foliage.

Tessless, pls read the top of the thread.

And the last one as we are officially done with the study: The mites can transmit onto a new rose after < 1h of feeding

The Master's Thesis that provided some/most/all ? of the research for this thread is now available free, see:

http://forums2.gardenweb.com/discussions/3776903/rose-rosette-virus-masters-thesis-free

ioannis, I just wonder if the mites only feed on roses. Also, is there anything that would repel them such as cayenne pepper spray? What is your opinion about whether pruners can spread RRD?

To my knowledge mites only feed on roses. Of course we do not know what we do not know..... Our lab is working on an additional two emaraviruses and we hypothesize that the genus evolves primarily by switching hosts rather than evolving to different species via the accumulation of mutations. How is this done? Most probably by the vectors switching hosts. Emaraviruses are mechanically transmissible under the right conditions but would not worry too much about pruning. it is an extremely inefficient way of virus spread.

Thank you! I'm glad you're studying this stuff. It is still hard for me to understand how a little mite can get the virus into a plant better than some virus getting in to a big cut on a plant. One person explained that there might be something in the mite's saliva that favors the virus, or maybe it takes time , as you seemed to be saying, for the virus to be transmitted.

One big worry for gardeners has been that a healthy rose's roots will grow into or graft into a sick rose's roots. So the thinking was that you have to get rid of all the sick rose's roots. I think that a sick old piece of root can live awhile. This kind of thing is one of the reasons RRD is such a dread disease....all the things you have to worry about. You think don't worry about roots either?

Destroying the complete rose with a herbicide has been suggested by the Professor for the exact reason. See discussion above.

I guess I don't trust herbicides to do the job. I thought the best practice was to spray the plant with miticide since mite populations are higher on infected plants, then spray with a herbicide, then spray with hairspray to immobilize any mites, then cut down the plant and dispose of, then dig up the roots. A lot of work. I have had a few RRD infected plants but a low percentage over a number of years, so it has not spread like wildfire here. Maybe because I am anxious about the disease and go to some trouble to get rid of an infected plant. Here is a page from Ann Peck's ebook that mentions digging out the plant:

http://www.rosegeeks.com/id34.htm

I use science to make educated decisions. There are a myriad of approaches to combat disease; its up to the individual to decide which ones to apply. My approach would be to either dig out the plant or if too big, prune it and apply herbicide to what's left behind.

Concerning spread by using infected pruners. The following (undated) report recommends disinfecting until long term studies have been done. Does anyone know if the long term pruning studies have been done? http://www.newenglandgrows.org/pdfs/ho_WindhamRoseRosette.pdf

"Pruning infected roses before pruning healthy plants with the same shears has been suggested as a method of transmission of RRV. Several researchers have investigated pruning as a method of transmitting RRV to other roses and concluded that pruning was not an efficient means of transmitting the virus to healthy roses. All studies had limited time (several months) for rose rosette symptoms to develop on pruned plants. This may not have been sufficient time for latent infections to become symptomatic. It is prudent to use caution when pruning roses suspected of being infected with rose rosette and disinfest shears before using them on healthy plants until studies with longer observation times have been completed."

Another comment regarding the statement: "The results: the virus moves to the roots - pruning is not a viable control strategy."

The information in the thesis (p.36) is:

"Systemic movement

A total of 20 RRD symptomatic and RRV-positive ‘Julia Child’ plants were tested for virus movement to the root. All samples amplified the internal control indicating the integrity of RT-PCR and 50% of the roots tested positive for the virus as determined by sequencing all amplicons."

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Later on page 72 the following is stated:

"Systemic movement of RRV to the roots is a significant fact to consider when making management recommendations; e.g. pruning out symptomatic areas, an ineffective measure for virus elimination."

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

The other place in the thesis where this point is discussed is on page 57:

"It is more often than not that rosarians only remove symptomatic tissue with the premise that RRV is not systemic and disease could be eliminated by pruning. We used a ‘proof-of concept’ approach using grafting, part of our resistance screening, and testing root tissue where mites are unable to reach and feed on. Based on these results management recommendations based on pruning of symptomatic areas are rather inefficient and should be avoided to minimize the persistence of the virus after overwintering in the root system."

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Earlier in this thread the following answer was given to when the roots were tested (at least I interpreted that the answer was to that point):

"We tested for the virus three months after we placed the mites on the plants - We used 'Julia Child' in those experiments."

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

Figure 3, page 68, are the roses in this picture similar (in size) to the roses that were used in the "virus in roots" testing? They appear to be relatively small (young?) plants. If they are similar to the tested roses, I question whether a general conclusion can be reached about whether the rose gardener who has mature roses, (including climbers) and who is conscientious about checking his/her roses for the first sign of infection should not try cutting off the infected cane at the root?

Also, please keep in mind that three months after infection 50% of the roots were infected (i.e. 50% were not infected).

I will repeat my earlier statement in this thread here:

" H.Kuska comment. How long does it take the virus to reach the roots (under all possible conditions such as a rose with partial resistance, high temperate or low temperature, plant in active growth, or rose not in active growth, etc. It is my understanding that the pruning may work if the infection is caught early (and even maybe only at certain times of the year)."

This question can not be unrelated to the time between infection and first noticeable symptoms. We have 3 significant events here: Time of infection, time after infection for virus to be detectable in the root system (or the bud union), time after infection for external symptoms to be recognizable. The relationship between 2 and 3 is important. Also, in the case of budded roses, the significant plant part seems to me to be the bud union not the root system.

I don't think this subject and all it's subtopics has been studied long enough to know for sure about some things. Henry, I always appreciate your curiosity, and wish to bring in more considerations before arriving at conclusions.

A few facts:

'Julia Child' develop symptoms in less that a month after infection.

The virus is systemic in rose (root testing but also grafting to almost 20 genotypes).

From studies in another rosaceous host (raspberry) we know that viruses can move to the roots in a couple of days.

Lack of detection, in lieu of gene silencing, may be because of low virus titer.

Till we had a detection test for the virus, we could not have known whether plants where infected with rose rosette or a rose rosette-like agent. Biology in never absolute and there are always exceptions to the rule. After all we have only evaluated a handful of genotypes of the myriad that are available to rosarians.

Still, the accumulated evidence since the discovery of the virus point to elimination of infected material as the better control strategy. Some people may agree to that, some may not. Till someone has experimental evidence to the contrary I would use caution in using anecdotal observations.

With this I sign off this group. Good luck combating the disease no matter which approach you use.

I have earlier given a link to another thread where I discuss the results on neighboring roses of applying RoundUp to test roses. Since each thread will scroll off of this forum at a different rate, I feel it is appropriate to put that information into this thread.

" To test for the occurrence of root grafting, experiments were conducted using the systemic herbicide Roundup®. Plants that were treated with the herbicide died as expected and approximately 50% of the adjacent, untreated Rosa multiflora ‘Burr’ plants and 10% of the adjacent untreated ‘Dr. Huey’ and ‘Sunflare’ plants showed mild herbicide toxicity symptoms. This could be explained if root grafting had occurred, allowing herbicide to move through the vascular connection between plants. "

In the full paper the experimental conditions were given.

"The Round-up tests utilized 470 multiflora plants, 148 plants of Dr. Huey, and 98 plants of Sunflare. The multiflora and Dr. Huey were planted approximately 11.8 inches apart (H.Kuska comment: it was not clear to me if they were mixed in the same row or in different rows). The Sunflare plants were planted 3.3 feet apart in rows. Roundup was applied to every other plant. The treated plants all died. About 50% of the multiflora plants showed roundup symptoms. 10 % of the Dr. Huey and 10% of the Sunflare plants showed symptoms."

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

I would expect that 3.3 feet apart would not be uncommon in many home rose gardens.

I cannot post the complete paper because it is copyrighted. However, I can send e-mail copies to a limited number of individual requests under the educational exclusion. My e-mail address is: kuska@neo.rr.com

The abstract is at: http://www.actahort.org/members/showpdf?booknrarnr=751_26

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Even the RoundUp label acknowledges that root grafting is a known problem:

This is the instruction
from the Round-Up label for cut stump applications:

"Apply this product
using suitable equipment to ensure coverage of the
entire

cambium. Cut trees or
resprouts close to the soil surface. Apply a 50 to 100
percent

solution of this product
to the freshly cut surface immediately after cutting.
Delays

in application may
result in reduced performance. For best results,
applications

should be made during
periods of active growth and full leaf expansion.

PRECAUTIONS,
RESTRICTIONS: DO NOT MAKE CUT STUMP APPLICATIONS

WHEN THE ROOTS OF
ADJACENT DESIRABLE TREES MAY BE GRAFTED TO THE ROOTS
OF THE CUT STUMP. INJURY RESULTING FROM ROOT GRAFTING MAY
OCCUR IN ADJACENT TREES. Some sprouts, stems, or trees
may share the same root system. Adjacent trees
having a similar age, height
and spacing may signal shared roots. Whether grafted
or shared, injury is likely
to occur to non-treated stems/trees when one or more
trees sharing common roots are
treated."

http://aggie-horticulture.tamu.edu/syllabi/325/schedule/Pest%20Management/Chemical%20Application%20&%20Safety/Roundup%20Original.pdf

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Title: "Glyphosate fate in soils when arriving in plant residues"

http://www.sciencedirect.com/science/article/pii/S0045653516304039

Apparently Stormy Weather did not pass further testing.

http://rosebreeders.org/forum/viewtopic.php?f=2&t=55260

Professor Tzanetakis is seeking a post doctorate to assist him in plant virus studies. I feel that he has been one of the leaders in utilizing next generation sequencing techniques for plant virus detection. I would expect that this would be an ideal sabbatical position for a younger faculty member who wishes to move to the forefront in this area of research.

https://www.sciencedirect.com/science/a ... 2214004437
https://www.google.com/search?num=100&n ... inevADK-TQ

https://www.google.com/search?num=100&n ... eHpgY59XWU

See:
https://www.higheredjobs.com/search/det ... =176712225