Is This Erwinia on my Phal leave?

[Jayfar]

Looks like it could be. If you're going to cut the leaf off and keep the plant, isolate it far, far away from your other plants. You might want to proactively spray your other plants with Phyton 27, which is systemic, unlike Physan 20, and clean all table/shelves surfaces with physan or bleach. That's what I did last summer when several phals got hit with what I believe was Erwinia following a prolonged period of high humidity. I only lost 3 or 4 plants and one Ambo that I was iffy on whether or not it was infected with the same has fully recovered and since rebloomed.

EDIT: Be sure to read the safe handling instructions that come with the Photon 27 and wear rubber gloves. It's fairly safe once diluted to the appropriate strength, but you do not want to get even a tiny drop of undiluted phyton on exposed skin.