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TasV
assistant gardener
Australia
157 Posts |
 Posted - 18/11/2008 : 19:08:06
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This is one of my unknowns that I'm urgently trying to ID because I like it but it is badly infected with rose mosaic virus. I'd like to either try to erradicate the virus and bud clean buds onto clean understocks or try to find a clean replacement (I'm leaning towards trying to clean it because if this specimen can be this healthy infected with RMV then it should be awesome without it). RMV causes the yellow patterns on the leaves (often called an oakleaf pattern) but look what it does to the flowers. Kinda attractive in that strange mutant kind of way 
I'm digging it out this weekend and potting it up into a large pot because I don't want it to pass on the virus to the other roses around it. Luckily it is not easily transmitted and the only documented way of transmission from rose to rose is by root grafting when plants are grown close enough together that their roots cross over and form natural grafts.
This is what it is meant to look like (during summer last year). The higher temperatures of summer kills most of the virus in the above-ground portions of the plant and it can again grow normally.
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Mary-Anne
garden sage
Australia
10809 Posts |
Posted - 18/11/2008 : 19:27:51
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Such a pretty rose too, sorry I cant help.
All the best with getting rid of that disease..
Friends are the flowers in the garden of life
Love Your Enemies... It Will Drive Them Nuts |
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Pamela
head gardener
Australia
3949 Posts |
Posted - 18/11/2008 : 19:44:03
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Gosh - how did the disease arrive?
"The air of heaven is that which blows between a horse's ears." |
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TasV
assistant gardener
Australia
157 Posts |
Posted - 18/11/2008 : 19:59:16
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It is normally transmitted when the grower grafts onto an infected rootstock or buds from infected plants. This one was here when I got here and was moved from its place in the shade out into my new main rose bed. It's much happier where it is but I have 'Bonica', 'Maurice Utrillo', 'Double Delight', 'Othello', 'Leda', 'Heidesommer', and an unknown yellow one nearby and I don't want to risk infecting them as they appear to be virus free at this point.
Normally, if the variety is easy to obtain, I shovel prune the infected plants. I've shovel pruned three this month that had RMV; 'Pat Austin', 'Mr Lincoln', and 'Pretty Jessica'. I have five more that I haven't got rid of yet and probably won't; 'Climbing Iceberg', 'Mutabilis', 'Altissimo', this one, and a plant of Dr Huey that I am keeping and cleaning so I can make lots of understocks from it (it's a pretty nice plant in its own right too). I'll try and clean all the others too. |
Edited by - TasV on 18/11/2008 20:15:56 |
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Cree
assistant gardener
Australia
76 Posts |
Posted - 19/11/2008 : 09:43:24
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Florida RMV irradication for bud wood only.
http://www.fshs.org/Proceedings/Password%20Protected/1985%20Vol.%2098/344-347%20(MANNERS).pdf
Your rose might be Colorama. I used to have it, looks like it to me. Also flowers were burned by the sun like yours. Discribed as Carmen red shading to soft gold at the center and reverse. HT 1967 |
Edited by - Cree on 19/11/2008 09:46:18 |
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TasV
assistant gardener
Australia
157 Posts |
Posted - 19/11/2008 : 13:05:56
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Thanks Cree... I'll check out that rose. Those marks are not sunburn... the mottling is due to the rmv affecting the normal expression of the colour and pattern in the flower. We haven't had enough sun, or high enough temperatures to cause this. We've only had a handful of days so far this spring over the 20 degree mark.
I've been speaking with Malcolm Manners about this and he's sent me a breakdown of how they achieve clean budwood at their facilities. The idea is to grow multiflora seedlings to use as clean rootstocks because the virus does not appear to be transmitted via pollen or egg and then subject the grafting material to 30ish days of temperatures of 38 degrees Celcius. You then remove budwood and graft it onto the clean seedling. In this way varieties that are considered to be chronically infected like 'Altissimo' or 'Cecile Bruner' (climbing) and others can be cleaned and natural vigour can be restored. The heat therapy is applied to plants that are neglected and allowed to dry out to induce dormancy, as would be expected during times, to help increase the chaces of surviving the heat therapy. The bottom parts of the plant are considered to still be infected and can the be destroyed. I have a tank with a thermostat and a heating element in it with a grow light over the top so I am going to have a go at killing off the virus. |
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Cree
assistant gardener
Australia
76 Posts |
Posted - 19/11/2008 : 14:10:02
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Tasv,
I took a quick look around and I don't see anyone stocking Colourama. I still have the tag from my old one but no grower is listed. I got it at a wholesale nursery supplier in Victoria. If you want to email me your address I can send you the tag, has a good pic of it and discription. |
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