Cherry tree progress super-enhanced: explanations please

I’ve seen one thing somewhat fascinating which I’m certain one in every of your readers would be capable to clarify: super-enhanced vigour of a cherry after infestation with black fly. Final yr we had two grafted timber of the identical selection on the identical rootstock (I’m certain), one yr outdated on the time, and one was closely attacked however the different (solely a few yards away) was not touched. As final summer time progressed and the black fly disappeared that tree placed on an enormous spurt of progress, actually thick new wooden with a little bit of a kink the place the brand new progress started. I assumed that the injury had stimulated the tree to make up misplaced floor, however curiously this yr the identical tree is continuous it’s super-enhanced progress (with large leaves), while the unaffected tree seems fairly regular!

I can solely guess that the aphids will need to have contaminated the tree with a virus of some sort, although since they’re in all probability rising from the identical rootstock (grafted on suckers from a close-by customary tree) a virus may be anticipated to journey again and have an effect on the opposite one?

Any solutions can be most welcome!

James Evans