There are a few topics discussing symptoms and whether to keep or discard tree’s with Apple mosaic virus.
But i could find little information on how infectious it is. Or how to effectively quarantine it?
I am also curious what most people do with traded scions or scions of older varieties that are not certified virus free available?
Do you just graft away on existing tree’s?
Do you quarantine them for a few years?
I received some grafting scions. And a scion in the bag possibly has Apple mosaic virus. I was planning on grafting that possibly infected scion onto a separate rootstock. And keep it indoors. For a long term project of trying thermotherapy to eliminate viruses.
My original plan was to keep the possibly infected tree indoors for 2 years (since it often does not show symptoms until than)
Unfortunately, the possibly infected scion was in the same bag as other uninfected scions.
So now i am wondering if i should quarantine all the tree’s i graft with those?
Multiple sources state Apple mosaic virus to be not that infectious. (limited/no insect spread, slow spread through infected tree’s. Mostly spread by lack of disinfection during pruning or grafting or natural rootgrafting from nearby tree’s.
How likely do you think it is for scions to be infected from just being in the same bag as an infected scion?
For woody field indexing, Fulton (1972) suggested that Malus silvestris cv. Lord Lambourne and
Jonathan be used, on which ApMV causes prominent mosaic symptoms. Mink et al. (1987) further
included the apple cultivar Golden Delicious. Cultivars Lord Lambourne and Golden Delicious are also
recommended for indexing trees in woody tests in
the field
seems like especially useful information.
I think i will quarantine the possibly/likely infected plant inside. Just to be sure.
And the plants i graft with uninfected scion that where in the same bag will be “quarantined” away from other tree’s. And get a graft of Lord Lambourne and jonathan. To see if they are infected.
I have only had one variety show mosaic virus and was very glad that it was not multigrafted. I ended up culling the whole batch of that cultivar including the attached rootstocks. They had been growing side by side with other potted varieties, but there was no spread. I always spray my grafting tools with alcohol between each cultivar as a precaution.
One of my trees has apple mosaic virus. It is a Rubinette. But it grows vigorously and produces very well. So I don’t pay too much attention to the leaf discoloration.
I have also multi grafted that tree and the scions are growing well.
I think it is highly unlikely. I would be more cautious with those scions that we think are without the virus. You never know. I would graft on separate virus free rootstock to which I would graft susceptible but virus free variety during summer and wait for 3-4 years.
I discovered possibility of the disease in my orchard last season and I will try few experiments myself as I have Jonathan apple.
This problem is important for me because I have to multigraft due to lack of space.