>Some have tried anti-transpirants to disrupt the mites, or miticides or Neem to try to kill the mites, and the disease still comes." I am interested in knowing who specifically tried these methods and reported that the treated plants got RRD? Hi Henry, I thought I had posted a response in this thread earlier and only realized today that I hadn't when I found the temporary file I was using to write this response still on the computer's desktop. I'm sorry for the delay. Anyway, I tried Wilt Pruf briefly in late May and again in mid June of this year. I only had enough Wilt Pruf for maybe 2/3 of the roses in May, but in June after the new Wilt Pruf purchase arrived I thoroughly gave them all a full shower of that anti-transpirant. For awhile, maybe three weeks, I didn't toss out any more plants to RRD (of the 48 that were sitting in pots all together with a few roses planted nearby), and perhaps if I'd tried reapplying it every couple of weeks, that would have worked. However, one variety--two plants--was horribly affected by the Wilt-Pruf treatment itself in June (and I think I recall that neither of those roses had gotten a full application of Wilt Pruf in May, if they had gotten any at all). The many other roses didn't show a very significantly bad response, but both General Gallienis reacted noticeably within half a day. One recovered, and the other one didn't. I am thinking that perhaps the really hot weather might have been the wrong circumstance in which to apply Wilt Pruf--that General Gallieni might have gotten by with Wilt Pruf applications in cooler weather. I don't really know why that variety was differentially affected though. Anyway, I quit trying to use Wilt Pruf regularly for protection during the summer and haven't gone back to using it, at least not at this point. By July I was back to having RRD-infected roses to toss out. If anti-transpirants do work for RRD protective purposes, you'd have to remember to keep doing it regularly (and I've no idea of the definition of _regularly_ here), since I did a thorough job in June and by fairly early in July was having to toss plants again. I did try Neem a few times, but nothing in a programmed way and nothing else I did worked either (pyrethrin). Just tossing the roses as soon as you see several symptoms seems the best bet, unless you've been keeping such a close eye that you know the disease symptoms are only a few days' old, in which case cutting out a cane is probably well worth a try. I kind of think RRD is gone from this yard now, but with cooler weather here now, it's going to be difficult to know for sure. The three roses that have had a single RRD-diseased cane removed are going to have to spend the winter isolated in a pot until I can see what the new growth looks like next spring. Somewhere recently I read that sometimes a plant can already have RRD but can take up to a year to show symptoms. Best wishes, Mary

Science can move rapidly. The abstract below was presented at the 2012 Petria -22nd International Conference on Virus and other transmissible diseases of Fruit Crops. Now that it is recognized that plants have an immune system against viruses (RNA Silencing) a logical next step is to use genetic engineering to add more RNA silencing molecular sequences. In the abstract below please note that they recognize that both low temperature and mixed virus infections can decrease the effectiveness of the plants natural immune system: "Since it’s known that some abiotic - low temperature - and biotic stresses - mixed viral infection - could have a detrimental impact on RNA silencing-mediated viral resistances," ---------------------------------------------------- Title: Robust and Wide Spectrum RNA SIlencIng Mediated Resistance TO PLUM POX VIRUS Authors: E. Di Nicola-negri(1), M. Tavazza(2), V. Ilardi(1) (1)Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per la Patologia Vegetale, Rome, Italy; (2)ENEA CR Casaccia, Via Anguillarese, 301, 00123 Rome, Italy Published in: Petria, Vol. 22 (3), 2012, 123-459, Abstract: "Plum pox virus (PPV) is a quarantine virus that causes sharka, one of the most important diseases of stone fruits worldwide. Seven PPV strains have been characterized, of which PPV-D, -M and Rec are the most important from an agroeconomical point of view. The best agricultural sustainable approach to prevent sharka disease consists in developing PPV-resistant plants. In this context we have shown that Nicotiana benthamiana plants transformed with PPV-M sequences (PPVIsPaVe44), covering the 5’UTR region, P1 and HC-Pro genes and arranged to express self-complementary ‘hairpin’ RNAs, are immune to the homologous PPV-ISPaVe44. However, as the RNA silencing-mediated resistance operates in a sequence-specific fashion, transgenic plants harboring the four hairpin constructs were also challenged with viral isolates belonging to different PPV strains. All the transgenic plant lines were resistant to PPV-D, ��"M and Recc strains. Moreover, the transgenic plant line harboring the 5’ UTR/P1 sequence was also resistant to isolates of PPV-EA and PPV-C strains that are distantly related to ISPaVe44. Since it’s known that some abiotic - low temperature - and biotic stresses - mixed viral infection - could have a detrimental impact on RNA silencing-mediated viral resistances, 5’ UTR/P1 plants were challenged with PPV under different conditions. Transgenic plants were resistant to PPV infection both at high (30°C) and low temperature (15°C). Furthermore, no susceptibility to PPV-Was observed in 5’UTR/P1 plants previously inoculated with Potato virus Y (PVY), Cucumber mosaic virus (CMV) or Artichoke mottled crinkle virus (AMCV) suggesting that prior virus-mediated expression of HCPro (PVY), 2b (CMV) and P19 (AMCV) RNA silencing suppressors was not able to defeat PPV resistance. The overall data suggest that the 5’ UTR/P1 hairpin construct can be profitably used to confer resistance to the sharka disease in Prunus species." The above is taken from a 338 page PDF document that gives the abstracts and/or full papers that were presented at that Conference. Here is a link that might be useful: Link to 338 page PDF document (long download)

I'm not sure of the specifics, but here's how I see RRD affecting roses -- both to further the spread of the virus, and also to result in the eventual demise of the rose. In the animal world, there are numerous examples of various parasite species causing changes in their hosts which facilitate the spreading of the parasite. I remember some examples of infected fish being attracted to swimming erratically near the surface, which makes them more obvious to avian predators. The parasite spends its second stage of life within the birds, so affecting the fish in this way would be an evolutionary advantage to those parasites. I think something similar is going on with RRD. The virus seems to trigger the rose to produce exuberant soft new growth which doesn't seem to mature. This is the type of growth which is most attractive to pests which feed on sap, so symptomatic growth would actually be sought out and fed upon more readily than asymptomatic normal growth. By creating an attractive and easy source of food, the virus is capable of spreading more easily. Of course, viruses aren't capable of thinking this through, but those viruses capable of engendering such physiological changes in plants which facilitate infection of new plants would also have an evolutionary advantage. Now, I don't know how RRD infected roses do in frost-free climates, but where Winters are real, those never-maturing soft RRD-infected growths would be decimated by the cold. Each year, an infected rose would have less and less live wood, and infected cells would be "forced" by the virus to continue producing this type of growth. Eventually, the reserves would be drained, and the rose dies. I'm not completely sure, but what I've seen of RRD-infected roses seems to indicate to me that the infected growth isn't really capable of photosynthesis -- or, at least, not to the degree of producing more food than is consumed by producing that type of growth. Just as a plant which produced blooms in lieu of producing leaves would eventually starve to death, my thoughts are that in frost-free climates, RRD-infected roses would similarly starve to death. But without Winter-kill, this would likely take longer. :-) ~Christopher

I use one of the rotating impulse sprinklers for the veggie garden, and in the few instances I’ve needed it, in the ornamental beds. Everything is well mulched and the soil is fairly rich in organics in the ornamental beds, so we need to go for more than a month without rain before the ornamentals need supplemental water. Because the ornamental beds all have shrubs and small trees, I use one with a spike that I can wedge into a tall piece of pipe or conduit so it reaches over the taller plants. I move it around the bed a few times to help even out any irregular pattern, and tend to run it for several hours, but only every couple of weeks. In the veggies, I run it when we go for more than a week or two without appreciable rain. I have a well, but I have yet to reach its capacity. In my previous home, with a good dug well, I did manage to run the well down once . . . But I had watered various beds for a day plus done laundry. I had weepy soaker hoses, and for me they worked really well, but were set up with a main feed that then forked off into a bunch of shorter runs, less than 20’. There were shut off valves so I could control which areas were getting watered, and the hoses were buried under mulch, so they were still functioning well after at least 5 years when we moved. The only reason I don’t have soaker hoses now is because the veggies are too far from the spigot at the house for easy set up.