My wife got a potted Early Italian prune tree, the tag says grafted onto peach root stock and doesn’t specify whether its Lovell or others. However, there is an intermediate length of trunk about 18" tall between the rootstock graft and the scion. This intermediate trunk looks like a cherry tree with dark greyish bark with speckles. Does anyone know what is going on here?
Tree
Root stock claimed as peach
Intermediate trunk and scion graft
An interstem of some kind, apparently. But what they’re trying to accomplish I don’t know.
Now that you have more pictures it’s easier to see what you are talking about. One of those two “unions” probably isn’t a graft. It’s more likely just a spot where the tree was cut back. It’s nothing to be concerned about.
If it is double grafting, it means that an intermediary has been inserted, for the purpose of controlling vigor or precociousness, or for resistance to external factors and diseases.
Which one the bottom or the top?
Interesting that they went with a peach root stock for (?) when peaches are now being increasingly grafted on plum root stocks. The tree has a few flowers, it probably had more but they might have fallen off during the transportation handling etc. Given that EU plums are known to take 7-10 years to fruit, the inter-stem could be what inducing early flowering? perhaps its some variant of plum.
Perhaps to prevent borers?
I don’t know really. I am not aware of such a function of an intermediary.
I know that plum is grafted with an intermediary for the purpose of vigor control (for example P. domestica grafted to P. cerasifera), and the intermediary is a dwarfing vegetative variety. If it is done for this purpose, the intermediary is longer, 30 cm or so. To resolve the incompatibility, a shorter intermediary can be used (which is not the case here anyway).
Just heard back from the nursery, apparently this tree was a multi-bud on Marianna 2624 interstem, other scions failed and this one grew.
