Huge fireblight strike on 7 year old Kentucky Limbertwig apple on G 30: A four inch sunken blight canker on the underside of the right scaffold branch where it meets the trunk plus about 180 degrees of trunk circumference is blackened but possibly no canker on the trunk proper.
If I carve off the canker and all the black is there a chance to save the tree? Surprised blight got into such old wood. Looks like toast doesn’t it?
Thanks for ideas.
I’m not a fan of the taste of Kentucky Limbertwig but now it belongs to my friend and she wants to save it. This variety has been Typhoid Mary here-it’s surrounded by hundreds of Callery pear volunteers, probably source of blight although nearby Keener Seedling, Black Limbertwig, Caney Fork Limbertwig and Paducah are pretty clean.
I wonder how far the blight has run down the trunk inside the tree below the black? Isn’t this crazy how it got such a foothold in older wood?
Maybe cut the whole top off at an angle about 4 inches above ground and bark graft to a much better variety. It has a nice root system. I’ve got the idea Ken LT will have blight problems forever at this site. Last year had to cut the top 1/3 out of the tree. This is why Enterprise, Freedom look better every day.
@rayrose Please expand. Do you mean blight extends inside the trunk a lot lower than the black? Like into the roots? Maybe I can saw below any discoloration in the heartwood. As I understand it blight goes no farther than the discoloration in heartwood. So if cut down to clean wood, should be ok, yes?
@Martin Yes, agree on disease prone interstem. Thanks for your perspective. Think I will lop and bark graft under the “nothing to lose” approach. Willing to put in a bit of time and then monitor. Will report back on how it does.
Sounds like it’s now critical to top graft a really blight resistant scion to keep blight away from the susceptible interstem. Liberty, Enterprise or take a flyer on Hunge or recently rediscovered Kittageskee that had a reputation for blight resistance. Roll the dice!
I think I would bleach the trunk before I cut it, and maybe after the cut too.
I have seen big blight strikes like that on trunks. That just stop all on their own, but I would not count on it.
That needs cut out
With fire blight , the living bacteria is mostly at the edge of a canker , in the cambium bark layer ,not in the wood or branch above.
So yes ,if you can scrape /cut out, back to healthy wood, with out reinfection , in theory it can be eradicated.
The problem being, it usually enters through a wound, the act of cutting it out creates new wounds, and your tools become carriers of the bacteria , so that’s why I recommended lots of bleach ( or other sanitizer) on tools and cuts before and after.
So- if I see a blight canker in the middle of a scaffold branch, the right thing to do is:
Shave off the canker down to clean wood, disinfect and I’m done? OR
Saw off the branch just below the canker?
Where does the blight in the canker come from? From the air straight to the canker site OR does it enter the tip of the branch and travel inside the branch all the way to the canker site and then erupt? If I knew the answer to that I’d know what to do.
Many times I see no evidence of blight on the branch above the canker. Thanks.