Rootstock effect on dormancy period

I’m interested in late dormancy, and late flowering apples. I know the rootstock and scion can have very different dormancy periods, for example with my Belle Fille De Salins, the scion is only just leaving dormancy now, but the rootstock (M7) woke up at least a month ago.

Can the opposite be true? Would a late dormancy rootstock delay an earlier leafing scion? Could you use something like a Court Pendu Plat interstem to delay leafing or flowering from an early scion in a late-frost prone area?

Cant say that I have seen anything regarding that technique, and we would probably know about it if someone had stumbled onto it and it was successful. With that being said I see no harm in giving it a trial run on a few young trees if you have the time and means.

My understanding is that rootstocks with the lowest chill hours requirements will wake up soonest.

But will a rootstock that’s late to wake delay a scion that’s not? That’s the question. It sounds logical, but does it actually happen?

Hi Casper - Last fall I made an informal note of when the various of my varieties dropped their leaves compared to the others. I wondered if late dormancy coincided with later maturing (which it did more or less, but not always). My grafts are on a variety of rootstocks, some same varieties on different rootstocks.The experience in my orchard was that the dormancy was individual to the variety and didn’t matter the rootstock. Many times the grafted variety and the rootstock dropped leaves at different times, and the same variety dropped similarly even when on different rootstocks.

Full bloom here happens over a week’s time or less (depends on weather) so a lot of overlap, and I haven’t paid attention to bloom time between a grafted variety and the rootstock. I have noticed Black Oxford is one of my latest bloomers and is also one of the latest to drop leaves in the fall (it’s on Antonovka). Crabs here generally are the first to bloom. Something to make note of in the future! Mostly the rootstock branches aren’t left to bear fruit but a few do. Interesting to compare the difference when the time comes. Sue

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