I started a bunch of seedling apples this year to fruit for fun/ have some extra rootstock kicking around. I plan to make some intentional crosses for fun in the future and this was a bit of a trial run.
Some (I would say close to half) of them have done something I wasn’t expecting and I was wondering if someone on here knew the cause.
They started growing straight up as your typical whip, but some stopped growing at 2ft or so and started vigorously branching out ( lateral buds popping like crazy often getting quite bushy). I trimmed the laterals off of most of them and they seem to be responding by going back to terminal bud growth and gaining height.
Here is an example of on of the seedlings I have in a nursery for rootstock (note the growth on top):
Some have done this all up and down the stem not just the top. My initial thought is that insect pressure is triggering this lateral growth. Am I correct in assuming that? I didn’t think they had that much but they have had random bouts of caterpillars, aphids, rose chafers and Japanese beetles.
Any other theories? Anyone else run into this with their seedlings?