I have successfully used it on citruses. It can control the growth of citruses without pruning and it induces early blooming for citruses grown from seeds. The major advantage is that the tree size doesn’t grow vigorously and so you don’t need to prune for about 4 years and then you do light trimming and another bark inversion again. You do this when you want to maintain the size of the tree, citruses specially because if you prune citruses, especially snipping off the terminals, you would have severe reduction in fruit production.
Bark inversion has been practiced by utility folks in Canada to maintain the roadside trees so they only need to prune the trees once a while instead of every year and saves a lot on labor.
Basically, you remove a ring of bark near the base of the tree on the main trunk, pull it out the ring of bark, turn it upside down and put it back and seal with parafilm. It reverses the polarity of the cambium in the ring of bark, limiting but not stopping the supply of nutrients into the roots. Without big roots, the tree remain small and so it concentrates the photosynthates into fruit production, improving the quality of the fruits. Similar in effect to mild girdling done on grapes or on selected branches of citruses.
Here’s a tutorial that I did to illustrate what Bark Inversion is all about. Make sure to read the descriptions on each picture as it has very good explanations and minor discussions about each step.
There are interstems that have ultradwarfing effect, provided that they are at least 5" long. I haven’t tried reversing the interstems though.
I know the scientific explanation or principles about the cambiums on the ring of bark inversion, similar to girdling, but the xylems would be problematic for a case of inverting both the cambiums and the xylem vessels and I haven’t come across peer reviewed articles about such. Maybe someone can point me into those articles.
Dang… I am severely limited in my responses as newbie. last night, I was told to wait 14 hours, now 10 minutes!!! before I can start replying again. They think I’m a robotic spammer…
the bark inversion literally means it, only the ring of bark is inverted, it doesn’t include the xylem vessels. Besides it is almost impossible if not extremely difficult to do a whole graft inversion of a very big tree on the main trunk…
Yes, sorry, I was replying to Auburn on his question about reversing the direction of the graft on interstems. I’ll have to find that old grafting book I read. I wouldn’t be surprised if your method was listed as well. The book had so many different grafts for nearly every situation, a fair portion of which I’d never even heard of before.
Anyway, thank you for sharing your knowledge. I always like learning new things.
I did bark inversion(sometimes also called ‘ring-barking’, on a couple of pecan seedlings, years ago… not sure where they are now, if still alive, but it did make a big, ugly knot at the inversion site, at least for a few years.
‘Looping’ (tying an overhand knot in a limber seedling) supposedly accomplishes a similar effect.
In my limited experience grafting upside down is very severe. I did it accidentally on an apple tree and the scion stayed alive but did very little growing. The other scions of the same ‘rescue’ tree on the same kind of root-stock grew vigorously. It sounds like this ring inversion is for trees that already have some stature, and now mostly are to be kept healthy and fruiting. Sounds good.
Just as an FYI, at the time of this writing, the system had already moved you to a level 1 (basic) so that should have solved the issue. I went ahead and moved you (again) to a level 2 (regular) just to make sure.
As you mention, the “Trust Level” system used by the forum is in place mostly to try to minimize spamming of the forum. It works pretty well (most of the time) but occasionally our forum “Alexa” can get a little heavy handed.