Knowledgebase
Is this fire blight? #874272
Asked June 23, 2024, 11:35 AM EDT
Montgomery County Maryland
Expert Response
Miri
We rarely see damage this significant on Black Tupelo (Nyssa sylvatica). Unfortunately, we don't have a concrete diagnosis from the photos, but we do suggest you contact a certified arborist who can assess the tree in person. Some of the larger tree companies have their own diagnostic lab in case they submit samples for pathogen testing, but companies that don't have their own lab could submit samples to nearby labs since the UMD pathology lab is temporarily closed (see the linked page for alternatives).
We can say that Fire Blight is not responsible for the symptoms if this is a Nyssa. Was any digging done in the tree's root zone (anywhere outside the branch tips or closer to the trunk) in the past year or so? Is there any visible damage to the trunk itself, like large scars or decaying holes from old branch removal?
If physical root damage isn't responsible, our working theory is perhaps severe Botryosphaeria canker, since it affects a very wide range of plants that are stressed (often by drought, which we experienced last year). Verticillium Wilt can cause wilting, collapsed foliage, but usually the damage from those infections is more widespread than the scattered tips visible currently. This might be something a lab can test for, however.
The pebbly, bumpy texture to some leaves (visible in the foreground of your last image) is commonplace and not concerning, as they are a type of mite gall which don't cause the tree any notable harm.
If samples are sent to a pathology lab, we would be interested to learn what the testing reveals, if a pathogen is detected.
Miri