Nectria cinnabarina? on a sharp's pigmy - how to rescue


this winter I’ve noticed some orange spots on my sharp’s pigmy nursery stock. According to a google picture search it’s nectria cinnabarina for which there is no cure.

Is this correct? If so, would it be safe to air-layer the other branches or are all parts of the tree infected now? If it is only a local infection where the spots are visible I was actually thinking of making a diagonal cut, to remove the left part and grow the right branch as a new leader.

What do you think?

So air layers above should be fine. Though this may be sacrificing the rest of the base if you do not remove that infected section. The removal hopefully wouldn’t be too bad. Have a look at the link below as this mentions some tips on how to avoid and prevention/treatment.