In the intervening years since this thread first circulated, I've seen a lot of improvement in my trees. I haven't seen this symptom in any of my tridents for three growing seasons now. Growth has been strong and healthy - even in the trees that had these symptoms before. But I don't think it was the Bravo, Mancozeb, or any of the other fungal sprays I used. This year, I haven't sprayed fungicide on my tridents at all.
What I think has helped a lot is to adopt a dormant spraying regimen. I've done this every year for the past four years - two spray applications while the tree is dormant. I spray dormant oil early in winter as soon as the trees are fully dormant. This is for bugs. Then in the late season I spray with lime sulfur for fungus. Timing of the lime sulfur application is critical:
- It should be done over four weeks after spraying the dormant oil
- It should be sprayed as the buds are swelling, but before they have opened
This last point is important, because if they've opened, the fungus will have become active and entered the living tissue - at that point, fungal infections become difficult, if not impossible, to control.
Watch this video:
Follow the instructions to the letter. You'll reduce your reliance on spraying with strong chemicals during the growing season and have healthier trees to boot.
Sort of curious how the trees the OP posted about are doing.