North American Fruit Explorers mailing list at ibiblio

[Lucky Pittman <lucky.pittman@murraystate.edu>]

At 10:56 AM 11/30/2006, Richard wrote:
> I believe cutting the bark halfway around the tree is called girddling. It's
> not a very wide cut so that it will heal over and next year the trees can be
> griddled again (at a slightly different place. This has been pacticed in
> China for 100's of years on Jujubes. It's hard on the trees though and I
> believe that with time the trees will be become stunted.

Several years back, Gordon Nofs sent me a transcript on an article on 
procedures used by Dr. Sax, former head propagator at the Arnold 
Arboretum; one of those procedures was bark inversion - removing a 1" 
or so ring of bark all the way around the trunk of a tree, replacing 
it 'upside down', and wrapping/sealing, as one would for a routine 
graft.  This bark inversion technique interferes with normal flow of 
sugars/auxins produced in the canopy, back down to the roots, 
resulting in dwarfing, and inducing earlier or heavier fruiting - at 
least for a few years, until normal 'flow' is re-established.
Similar effects can be achieved by tying an overhand knot in the stem 
of a limber young seedling.

I've done bark inversion on a few pecan seedlings and a few seedling 
apples - makes for a fairly ugly burl at that site, but to date, I've 
not yet seen any nut production from the trees I tried it on.

I think I've still got the article, in its entirety.  If anyone wants 
a copy, email me direct and I'll send it as an attachment.

Lucky