Can I use grafting to speed up flowering?
I have grafted scions of American persimmons onto mature trees and then had them fruit the next year. My question is whether a cutting from a one-year old seedling grafted onto a mature tree would produce flowers (and fruit) similarly the next year. I would be doing this to decrease the time between generations of crosses for an American persimmon breeding project. So the question is basically: does scion juvenility persist when grafted outside the zone of juvenility on a mature tree. I realize this is not normally done -- which is why I don't know the answer and haven't read about it anywhere either. Thanks.!
Michael Byrne -- Lawton, Michigan
No would not work to hurry up flowering. The one-year-old seedlings are still in their juvenile stage and not capable of flowering until they transition to the adult or mature phase when they are capable of flowering. The potential to flower is determined by the phase of the tissues. seedling plants begin as juvenile plant and may have different characteristics than adult plants such as thorns, different shaped leaves and the ability to flower. as the plant grows the new tissues transition to the adult phase losing their juvenile characteristics and become able to flower. The juvenile tissues in the plant are always Juvenile. I can think of several examples. You only see pine cones in the tops of conifers no the bottoms, in Oaks retaining leaves through the winter is a juvenile characteristic. In the fall you see leaves fall from the larger oaks but not the small young oaks and even on the older trees you see the leaves retained though the winter in the lower interior of the tree, where the tissues are still juvenile.
When we graft scions from a mature bearing tree onto another mature bearing tree the grafts will flower. Grafting mature tissues onto juvenile tissues, as you would do when grafting to a rootstock or a seedling tree results in mature tissues growing from the mature bud which was capable of flowering. In the reverse which you are thinking of you would be grafting juvenile tissues into a mature tree and the new growth would still be juvenile and not capable of flowering until those tissues transitioned into mature adult tissue. Many breeder wish they could do what you want to do.
You can search the internet looking for 'Juvenility in Plants' and find a lot of information, slide shows, and other references.