I’m in Louisiana, having a few problems with trident maple.
My new emerging leaves have black on the tips and the rest looks like sunburn, but the tree is watered and in part shade in summer heat.
Is this a fungus and if so what should I do moving forward?
I am in a completely different climate (much drier) so take what I say with a grain of salt (for you, not the trees!). If you have fungal issues on your other trees or in your yard I would suspect a fungus. The main fungal issue I have is powdery mildew on Norway maple seedlings (not in my other maples or the yard Norway maples).
I have seen that type of damage on some of my maples as a result of too much sun when they go a bit dry or if I keep them too wet. It looks like you have fertilizer bags on the soil and that can create an ionic imbalance in the soil (even with organic fertilizer) that drives water from the tree into the soil.
Hopefully someone in a climate closer to yours will chime in.
I also see this when I over fertilize (regardless of type) or over water any of my maples (tridents and Japanese). I also am in a different climate but I typically pull off any left over fertilize and focus on letting the tree get closer to the “dryer side” …for a maple! goodluck
