I have noticed something rather interesting which I’m sure one of your readers would be able to explain: super-enhanced vigour of a cherry after infestation with black fly. Last year we had two grafted trees of the same variety on the same rootstock (I’m sure), one year old at the time, and one was heavily attacked but the other (only a couple of yards away) was not touched. As last summer progressed and the black fly disappeared that tree put on a huge spurt of growth, really thick new wood with a bit of a kink where the new growth began. I assumed that the damage had stimulated the tree to make up lost ground, but interestingly this year the same tree is continuing it’s super-enhanced growth (with big leaves), whilst the unaffected tree appears quite normal!
I can only guess that the aphids must have infected the tree with a virus of some kind, though since they are probably growing from the same rootstock (grafted on suckers from a nearby standard tree) a virus might be expected to travel back and affect the other one?
Any suggestions would be most welcome!
James Evans
Fruit Forum 