Replacing rootstock on mature Fukomoto?

[harveyc]

I have a friend with a small commercial orchard of Fukumoto.  I forget what rootstock that was used, but it's one that was later determined to have poor compatibility with Fukumoto.  His orchard is at least 10 years old and he replaces some trees completely each year when the tree health is very compromised.  Is it feasible to plant a new rootstock next to the existing trees and do an approach graft?  I'm guessing he might not get this sort of advice from a nursery since they'd prefer to sell a new tree.  I couldn't find any discussion of this online. Thanks.

[Millet]

Harvey look under inarching graft - Millet

[harveyc]

Okay, thanks, I'll search those terms.  He's already done some inter-planting over the past few years.  Wish he had looked into this first.