Ok, so I have started doing stem injection treatment for Elm leaf-beetle.
I'm using the 'Wedgle Direct Inject' system which only has a small hole that goes in as far as the the bark/wood interface.
Elm beetle will probably be around for many years to come, and I anticipate having to re-inject tree in the future. I'm hoping to get 2-3 years of protection from each cycle of injection...seems to be possible based on previous efforts by others.
SO what I'd like to discuss is, what do you think the long-term impact will be on repeatedly injecting a tree around its circumference probably 3 yrs. apart.
The initial injection sites are staggered vertically so there is not a horizontal 'zipper line', rather if there is any damage to tissue that it would be spread out and separated.
You can't use the same area for subsequent injections, so in two or three years, I'd be using the spaces left from this go around...and in three years from then, another area...and on and on.
I've seen trees cut down that had repeated attacks from string trimmers at their bases, years of small compartmentalized wounds, but plenty of sapwood between them...somewhat debilitated trees to be sure, but still functioning.
The trees I'm talking about are big, old established trees, still actively growing, but is there a risk of gradually causing any girdling effect? Of causing more harm than good, i.e, the cumulative physical effect of repeat micro-injections outweighing the effect of insect control?
My initial thought are that wall 4 would come into play, and next year there would be a layer of new sapwood over the injection site, and more layers in subsequent years...but how often could you introduce small 'defects' before they collectively became a problem...or is this just one of those impossible 'what if' scenarios!
I'm using the 'Wedgle Direct Inject' system which only has a small hole that goes in as far as the the bark/wood interface.
Elm beetle will probably be around for many years to come, and I anticipate having to re-inject tree in the future. I'm hoping to get 2-3 years of protection from each cycle of injection...seems to be possible based on previous efforts by others.
SO what I'd like to discuss is, what do you think the long-term impact will be on repeatedly injecting a tree around its circumference probably 3 yrs. apart.
The initial injection sites are staggered vertically so there is not a horizontal 'zipper line', rather if there is any damage to tissue that it would be spread out and separated.
You can't use the same area for subsequent injections, so in two or three years, I'd be using the spaces left from this go around...and in three years from then, another area...and on and on.
I've seen trees cut down that had repeated attacks from string trimmers at their bases, years of small compartmentalized wounds, but plenty of sapwood between them...somewhat debilitated trees to be sure, but still functioning.
The trees I'm talking about are big, old established trees, still actively growing, but is there a risk of gradually causing any girdling effect? Of causing more harm than good, i.e, the cumulative physical effect of repeat micro-injections outweighing the effect of insect control?
My initial thought are that wall 4 would come into play, and next year there would be a layer of new sapwood over the injection site, and more layers in subsequent years...but how often could you introduce small 'defects' before they collectively became a problem...or is this just one of those impossible 'what if' scenarios!