Ugly spot on leave

[Orquiadicto]

I detected this ugly spot on the leave of one of my phals.
Any idea of what it can be? Should I cut the ugly part of the leave? The rest of the plant and the roots seem healthy.

[Kelo]

Looks like some kind of rot. I would cut out to half an inch beyond the damage and dust with cinnamon or some other fungicide to prevent further spread.

[Eyebabe]

It looks like Erwinia

Cut if off the plant leaving at least one inch of clean tissue margin.

[RosieC]

I agree with Eyebabe, after cutting it also dab the edge of the cut with cinnamon powder.

Erwinia can spread fast both on the plant and to other plants. You need to act fast to cut away the infected part.

[fishmommy]

yep, looks like erwinia and it is very serious!
cut the leaf back and practice very strict hygeine because it can spread like wildfire.
I recently had a bout with this and found that Phyton 27 worked best to stop it.
Check your plants daily to make sure it doesn't spread - it can melt a whole plant practically overnight!