I am no sort of expert, but it really looks like just an unhappy rose - RMV is large light splotches or veining on otherwise regular looking leaves. This guy looks stunted, and a bit chlorotic.

How much air circulation does the plant get? My only thought would be spider mites -Are you familiar with the signs/symptoms they cause? Spider mites have caused stunted leaves on my plants before. They will also busily suck one plant dry, while the plants around it are fine.

Hopefully other people will chime in, too!

Best,
Lara

Here is a link that might be useful: RMV leaf

Any chance of herbicide use nearby ... Round-up, Weed n Feed, etc? Based on your two photos, it looks like herbicide damage. Chances are, the rose will recover ... it'll just look bad until it does. I accidently did this to Glenn Dale last year, and he's fine this year.

Connie

I would stop spraying it until you figure out what the problem is. Does not look like any of the usual fungi. April is too early for spider mites. It does look like herbicide drift damage, but you say it was there last year too so you would have to know if the same herbicides were sprayed near it last year as this year. Actually doesn't have to be a spray. I hear Preen, and other soil-applied herbicides, can damage roses through the roots. If this rose is directly downhill of or adjacent to an area that is treated with Preen every spring, well that could be it.

Could also be frost damage. If this rose is in a cold pocket then the others wouldn't necessarily be hit too. Low spots tend to be cold pockets since cold air flows downhill like water does. Low spots also tend to have poor drainage or waterlogged soil, which could cause significant problems for your rose...

Probably not rose mosaic virus. I've never seen it stunt or deform leaves to this extent. They're just marked with yellow rings and spots and may be slightly smaller than normal.

Herbicide drift is a possibility, as is a deficiency of a nutrient such as zinc. Is it on all the canes? If you could get a picture with a sharper focus, that might help.

I took some new, sharper pictures this morning. They are on this link. Each of these roses is treated exactly the same. The bad cane is about 15ft long. It was pruned and pegged which is why it is angled downward.
I've included another cane with some normal new growth from the same bush for comparison.
None of my neighbors have used herbicides so early in the season as far as I know. Also, I would expect drift to affect more than this one cane.
Btw, these roses were ravaged by rose midge last season from mid-summer on. I can't imagine rose midge so early this year, but I figured I share that with you.
You can click on these pictures to enlarge them.
Thanks
Al

Here is a link that might be useful: Additional New Dawn damage photos

Myself, I would probably cut the bad cane way back below the odd leaves--back to some spot that looks like it might have a new leaf bud emerging. Then I would just keep an eye on it and see if it grows "good" or not.

Kate

I don't know whether rose rosette disease is yet in the metro New York City area, but if it isn't yet it is on its way. I am not sure what your New Dawn is suffering from. It does look to me as though it could be herbicide damage, but unfortunately it also looks to me as though it could be RRD. I have no personal experience with RRD, I'm only working from Ann Peck's webpages on it, but it occurs to me that you might want to read up on the disease, just in case. I think I've read before that New Dawn seems to be especially quick to show symptoms when it's become infected with RRD.

good question..my New Dawn in doing the same thing. Figured it was getting too big on one side of arbor, so cut it to the ground. It is throwing up long slender canes this year. Hmmmm! Here it comes. I sprayed the sidewalk cobbles with round up Extended. Fantastic on the walks this year. But I think many of the others are right. Mine has herbicide damage , I think! Tried to give this rose to a friend last year, but have you noticed many people who would like to have some of your roses are not willing to dig them up?

Just cut the bad cane back. It could be a speck of herbicide or some other damage to the cane such as canker. borer. or winter damage. It does look rather like a trace element deficiency, but that wouldn't affect just one cane.

I second herbicide damage. I've had that myself. If that's it, it will right itself soon.

Or it could just be a reaction to some cold nights when leaf buds are forming. I have that on a few roses, I get it every spring. That too will right itself. It's not fungus, so stop spraying. Water the rose well and see what happens.

When I read York Rose's suggestion that it might be RRD, I searched the net and then raced out of the house to take a closer look. The cane has many of the symptoms, including the "witches broom" growth. However, the new growth is not red, and there is no excessive thorniness. Still, it clearly could be RRD.

As I continued researching the internet tonight, I came across Rose Spring Dwarf disease, also a virus. I found very few pictures. However, the articles say that growth later in the season returns to normal. Son of a gun, that's what happened last year! I didn't think to mention this in my original post.

Does anyone have experience with this disease?

I really don't think it's spray damage, because only one cane is affected, all four of my ND's are against a fence, and there has been no spraying or Preen on my side of the fence.

Thank you all for your input.

I'm with michaelg. What it looks like is some sort of cane damage that affects how nutrients get to the growing leaves. If the laterals closer to the crown look OK, you can cut back to there.

It is hard to tell from the photographs, but there may be a small borer hole near the end of the cane. That would be consistent with the problem.

Spring dwarf is a systemic virus that affects the whole plant, not just one cane. If one cane is bad, there is something wrong with that cane, so it needs to be cut back.

michaelg, can you supply a modern reference for your statement "Spring dwarf is a systemic virus that affects the whole plant, not just one cane"?

A virus infection enters somewhere and I expect that its spread will be resisted by the plant's immune system.

A recent full paper concerning Rose Spring Dwarf is at:
http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PDIS-92-4-0508

Of interest is that it spreads by aphids.

Also of interest is that it appeared in their virus indexed plantings: "In this test, RSDaV was
detected in many different rose species and
cultivars from the Foundation Rose Collection
at FPS. In all, 129 plants in this collection
were tested, and 77 were positive
for RSDaV. Some of the hybrid rose cultivars
tested positive for RSDaV included
Queen Elizabeth, China Doll, Heirloom,
Lowell Thomas, Jack Frost, New Dawn,
Uncle Joe, Bridal White, Butterscotch, and
Cynthia. It is interesting that the virus was
detected in more than 69 plants in two
rows (total number of plants in these rows
was 89) of the collection which were
planted in the mid 1990s. In all, 162 samples
of R. multiflora from the virusindexing
rose blocks also were assayed in
the spring and RSDaV was found in 94
plants. The majority of RT-PCR-positive R.
multiflora plants were symptomatic. Another
40 additional plants from the same
virus-indexing blocks were tested in the
summer and 6 were positive."

Here is a link that might be useful: link to Davis paper

On the other hand, the species of the rose family often don't have very vigorous immune systems. That family is notorious for its profligacy, as well as its susceptibility to various infections. The species of that family (whether you consider apples, pears, cherries, peaches, raspberries, blackberries, or strawberries, or just about any of the others except maybe Potentilla) seem to spend a lot more effort on making babies than trying to preserve themselves. It's almost as if the Leitmotif of the family was, "If we make as many babies as possible, when the plague hits maybe some of them will survive to make their own babies."

:)

Concerning whether plant viruses are systemic (i.e. is the entire plant infected).

In 1995 Davis reported in a reviewed scientific publication that:
"The California Grapevine Certification Program has been based on two assumptions about leafroll disease in grapevines: that the disease does not spread significantly in the field in California and that the viruses that cause the disease are evenly distributed in infected vines. Careful testing of the Foundation Plant Materials Service vineyards at Davis using a new ELISA test suggests that these assumptions are not true. Changes in the California Grapevine Certification Program are underway as a result of this new information." ( http://californiaagriculture.ucanr.org/landingpage.cfm?article=ca.v049n01p26&abstract=yes ). From the abstract one can click on the "Full Text" PDF to examine the full paper (you may have to hold down the control key).
The following is a quote from the full paper: page 28 "The results revealed that for a few of the tested vines, samples collected from one side'were ELISA positive while the opposite side tested negative. These results suggest that in some vines GLRaVs are not distributed uniformly.".

Is this still considered to be accurate? The following 2008 newsletter states: Page 37 "The R&C Program was guided at the outset by two assumptions about grapevine leafroll disease. The existing state of scientific knowledge at the time was that grapevine leafroll viruses spread only by grafting healthy stock with infected stock and did not spread naturally in vineyards. (Golino et al., 2002; Goheen et al.,1959).
The second assumption was that the viruses that caused leafroll disease were evenly distributed through infected vines. (Rowhani and Golino, 1995). New technologies and many deteriorating vines later proved both assumptions inaccurate." (
http://fps.ucdavis.edu/WebSitePDFs/Newsletters&Publications/GrapeNewsletterOct2008.pdf )

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

The key 2000 Mourey et.al. paper that documented uneven virus distribution in roses is at: http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PHYTO.2000.90.5.522

It gives a reference to a 1998 paper that they summarize as stating: "virus distribution in the plant is often heterogeneous (1)."

It also states:

"ELISA test of cuttings. Six to eight single-node cuttings (approximately 5 cm long) of healthy and PNRSV-infected Anna and Lnidas plants were excised in the medial zone of floral stems at anthesis. Basal ends of the cuttings were dipped into 0.5% (wt/wt) ï¢-indole butyric acid. To protect them against fungal infection, they were treated with 800 mg of pyrimethanil (SCALA; AgrEvo, Berlin) per liter. Cuttings were cultivated in perlite in a heated glasshouse (minimal temperature 25°C) at 80% relative humidity. After 15 days, the rooted cuttings were transferred to a culture room at 22°C with a 16-h photoperiod. For each cutting, leaflets from the axillary leaf were tested by ELISA when cuttings were removed from the mother plant. Young shoots grown from the axillary buds of each cutting were tested by ELISA when they were 2 to 5 cm long."

Table 1 in the paper tells the number of days after the mother plants were tested that the leafed out cuttings were tested (30 to 86) and the number of samples (48 to 76).

In the conclusion section they state: "A total of 89% (59 out of 66) of Anna stems was entirely PNRSV negative when axillary shoots from these stems developed after the decapitation of the floral stem, after the development of cuttings, or grown in vitro were tested by ELISA. ELISA tests of leaves from these stems were all negative. Since IC-RT-PCR conducted in parallel on all the explants from three (out of seven) of these stems also were negative, we suspect that these stems were virus free, even if they belonged to infected plants, or that the viral titer was very low in the stems."

Please notice the conservative word "suspect" and the conservative statement "or that the viral titer was very low in the stems." In my experience this is the normal way of stating results as scientists realize that our interpretations and experimental methods are not normally "absolutely definitive".
--------------------------------

How could this information be useful to a rose gardener? First an example. If one finds that a branch that shows signs of RRD, the RRD literature suggests that if one cuts off the branch at the ground level that the plant "may" be saved. I have followed this advice and saved several important plants.

Now, if a rose grower finds virus type symptoms on one branch; the older "Rose Virus" literature is telling him/her that it is futile to try to save the plant by either cutting off the diseased branch or by taking a cutting from a distant branch for a new start. I suggest that the literature should state that at present there is some scientific evidence that one "may" be able to obtain a virus free plant from cutting starts. And, by analogy to RRD, possibly cutting off the infected care at root level may save the plant.

Here is a link that might be useful: 2000 Mourey et. al. rose virus paper

Because this my second year with this problem, and because it so closely matches the descriptions of RRD and/or Spring Dwarf disease, I'm going to assume it is a virus of some sort. I guess I'll cut down the offending cane and then monitor the rest of the season. Henry's link mentioned New Dawn as being affected by Spring Dwarf. That is some solid evidence, though I didn't understand much of the research paper. I was never good at organic chem.