If you read the Shigo study from the 70's he found that in a 5 year period the painted wounds had more decay, after 5 years there was no differeance the unpainted or any of the painted.
The purpose of the study was to find out which product worked better and the unpainted were just controls for the experiment.
So it showed not that painting is inherently bad, but that pruning paint is a waste of time and money. There was some evidence that tar based products killed the initial meristem push ie true callus per Shigo's definition (callus the precursor to wound wood in his dictionary)
there is no difference, it is the same attractant with some vector insects. There is s school of thought that elm bark beetle is just as attracted to the scent of buds growing (think of populus in the spring, how you can smell them down wind) because the adults feed at twig unions.
So one idea is that pruning paint is effective in masking this attractant on a wound when the adults are active. Or in the case of oak wilt, when fungal mats are sporing.
A study in the Twin Cities showed a higher mortality in dormant pruned trees then in trees that were pruned after storms in the summer.
I think Nels was being sarcastic here, or at least trying to pull someones chain
. He probably would have gutted the inner canopy more too, the meethod I call "raise and gut"
Something like that too, but i would probably done more reductions to reduce the number of stems in the canopy Leaving more inner canopy.
That is part off it, green mass feeds the closest tissue first, a bigger factor is that in the heat of the summer the branch ends will go semi dormant and partially wilt. This inner canopy is the only functioning tissue for photosynthesis, so trees that have had the raise and gut are more prone to heat and drought stress.
Ugg, too long, did anyone read all that?