Phal gigantea with yellowing leaves

[fotofashion]

My P. gigantea is losing its leaves one by one. It dropped one leaf last week and the next oldest one is turning yellow (really more a gold color) from the tip. This is not a seedling plant either. The leaves are a good 12" long. I paid a lot for this plant and do not want to lose it. The first sign of problems manifested itself in the spring when a new leaf started growing. It got about 1 1/2" long and then started drying out from the tip. It has not developed any further. The plant is mounted on a bark slab, is hung where it gets good light and fertilized weekly/weakly. Help!
Beverly A.

[CPKidofAugusta]

A couple of questions:

Are the yellowing from the crown down to the roots or from the roots up?

Have the roots recently incurred damage recently?

[fotofashion]

The yellowing starts at the tip of the leaves and progresses toward where they emerge from the main stem or crown, of the plant. I see no damage to the roots.
Beverly A.

[CPKidofAugusta]

I apologize, I've been away from the computer for a while.

How many leaves has it lost and where are the leaves being lost from: the bottom where the roots come out the top or where the new leaves come out?

[MattWoelfsen]

A picture would go a long way to determining the problem.

[fotofashion]

The plant had four leaves. One had fallen when I wrote in about the problem. The second one was just about all yellow when I cut it off near the main stem. The newest leaf grew only about 1 1/2", started browning at the tip and I cut that off. I have since remounted the plant onto a new piece of bark and given it new moss. I also painted the cut parts with cinnamon. The leaves are falling about the way old leaves usually fall from a plant-at the place where they emerge from.
I took the plant with me to the HOS meeting on Thursday and was given very little encouragement as to its hope for survival. Was told to spray it with fungicide but Which One? Another piece of advice was what I have done-remounting, trimming and the cinnamon. I guess that, at this time, only time will tell.
As to a picture, well, I already cut off the leaf and it is probably in the compost heap. If the next leaf starts to yellow, I'll take a picture. Thanks for your help.
Beverly A.

[CPKidofAugusta]

Where they emerge from? I believe giganteas are prone to crown rot, I don't know first hand but they have a reputation for that. If it is rot and you can keep the last lea(f/ves) you might be able to get a basal keiki.

[fotofashion]

Yes, that was also mentioned (the crown rot) but when I cut off the new leaf as far as I could, what was left was green, not rotted. I have not seen anything I would consider as rot. The leaves have just turned yellow, no black or mushiness typical of rot.
Beverly A.

[CPKidofAugusta]

Lets try cultural conditions. Your original post stated that you water and fertilize weakly/weekly. Does that mean that it only gets watered once a week? Because a mounted plant would need an awful lot of moss to keep it moist enough for that long.

But more generally, what are your cultural conditions? Light, temp, etc.

[Oscarman]

How about a picture of your plant as it is now Beverly. Let us see what your working with.

I only recently started growing gigantea, but would suspect cultural aspects are the concern. leaning towards changes in watering, temperature or light levels.

Hope it is doing OK.