Rapid yellowing of Phal leaves

[Tukatuka]

Hi,

It does get water on the crown because of natural rain and the plant being outside. But the body and crown feels firm and are a heatlhy shade of green.

I have had Phals in a pot that I carefully water die of crown rot, where the whole body slowly erodes with a black lesion. In that particular plant the leaves also starts to drop like this current case, which is why I keep checking the body for any evidence of softness.

Regarding the rain and water in crowns, isnt this what happens naturally in forests? This plant has adapted to this by slanting its leaves downward, it looks like it may topple over.

Should I spray it with anything? What if another leaf yellows?

Thank you