Canker/blight affecting Aronia melanocarpa in a bioretention pond. - Ask Extension
Hello, I'm trying to identify what looks like a blight affecting Aronia melanocarpa in a bioretention pond. After removing invasive weeds that were...
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Canker/blight affecting Aronia melanocarpa in a bioretention pond. #828005
Asked May 01, 2023, 5:17 PM EDT
Hello, I'm trying to identify what looks like a blight affecting Aronia melanocarpa in a bioretention pond. After removing invasive weeds that were covering the plants, I discovered that many of the branches of the aronia appeared to have areas where the bark looks like it had been peeled away. I eliminated it as deer pressure. I could not find any insects present. I was wondering if it could be fire blight. it appears to be a canker and at some points gridles the branch. Any branch that has it is dead or dying. Almost all the branches show signs of it. Some of the bark cankers are at the upper levels of the branches and some are at soil level. I am just having a hard time finding out what this is. If it is fire blight, should i trim back and remove the plants and all of its suckes? Thanks.
Baltimore County Maryland
Expert Response
These symptoms do not appear to be caused by an infection like a canker-causing blight, nor is it due to fire blight, whose stem dieback begins at the branch tips since the bacterial pathogen enters the blooms. With a canker infection, the tissues underneath the bark wound would appear darker, sunken, and/or deteriorated. Instead, this appears to be animal feeding, and if not by deer, then likely rabbits or a rodent, possibly over the winter (though not exclusively) as the sapwood under bark has nutrients when other food sources are scarce.
The branches with the damage are dying/dead because the vital sapwood transporting water and nutrients into the top growth has been damaged or removed. The innermost wood on tree and shrub trunks and branches is dead tissue (naturally) so will not be able to regenerate this lost sapwood. There is some callus tissue forming over the wounds that we can see in the photos, so perhaps some will recover in time and can sucker near the point of damage (though probably not beyond it if it's stripped all the way around the stem). Otherwise, yes, cut back all injured branches and as long as the plant's root system is still healthy, regrowth should appear from the base stems or root system to gradually replace what was lost. Chokeberries are, fortunately, fairly vigorous plants.
Miri
The branches with the damage are dying/dead because the vital sapwood transporting water and nutrients into the top growth has been damaged or removed. The innermost wood on tree and shrub trunks and branches is dead tissue (naturally) so will not be able to regenerate this lost sapwood. There is some callus tissue forming over the wounds that we can see in the photos, so perhaps some will recover in time and can sucker near the point of damage (though probably not beyond it if it's stripped all the way around the stem). Otherwise, yes, cut back all injured branches and as long as the plant's root system is still healthy, regrowth should appear from the base stems or root system to gradually replace what was lost. Chokeberries are, fortunately, fairly vigorous plants.
Miri
