Does Paclo affect wound closure?

[Alec]

In a juvenile American Elm that had been treated with Paclo a few years prior, many cuts as small as 1" dia. were still far from closed, with wood decaying. The tree is in fine fettle and had been growing at a good clip prior to treatment.

If Paclo is slowing growth might it also be inhibiting wound closure? A friend suggested Paclo might inhibit primary but not secondary growth, but the lack of wound closure seems to contradict that. Anyone know if Paclo inhibits secondary growth as well as primary and if that affects would closure?



@KTSmith , @guymayor, @ATH , @colb , @evo

 

[KTSmith]

I don't know of any research on the effects of an anti-gibberillin on tree wound response. I know I haven't done anything with that. I'll poke around a bit in the research/practitioner space.

 

[ATH]

I found a couple of articles. Sounds species dependent.

https://www.jstor.org/stable/43594794 - it is about impact on Syzygium Campanulatum (not familiar with it - nor any other Malaysian species!)

You need to create account to read full article, but it is free...or log in through your library.

Towards the end of the article, they report findings of reduced xylem thickness by 48.6%. They cite studies that found similar results peach trees and mango trees.

So, if xylem thickness is reduced each year, it seems reasonable it to assume that wound closure would be slowed...right?

Then more direct to the question:
https://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=209&Type=2 (will download a pdf)

in the abstract states:
"The rate of pruning wound closure was reduced in black walnut, European black alder, red oak, sweetgum, and white oak, but was not influenced by paclobutrazol treatment in white ash, white pine, or yellow poplar."