Phalaenopsis bellina - leaf tips darkening, turning yellow, spreading down leaf

[OzPhal]

Hi Everybody,

I was hoping to get some advice on the following:

Plant: Phalaenopsis bellina seedling 6 leaves so it is i would probably say 12-18mths old
Growth Conditions: Semi-Hydroponic, 25oC - 30oC, 70%-90% humidit, grown in a covered aquarium (with other seedlings), has an aquarium heater in the reservoir to keep the water at 25oC along with a large fan for air-movement. The whole setup sits in front of a south east (Australia) facing window with lace curtain in front of it. I have fertilised in weak concentration with Growth Technology "Orchid Focus"

I have this seedling sitting in its own independent reservoir within the aquarium. There is some algae growing in the reservoir. What i have noticed is that the older leaves, one at a time, start appearing thinner at the leaf tip, then the tip goes blackish and dry. Then yellowing starts to move down the leaf gets to about halfway. To date only one leaf has been effected in this way - i looked over the plant and gently moved the leaf and it fell off in my hand. The base of the leaf was yellowed. A second leaf has started to show the blackening tip with the descending yellowing.

Any advice? The plant is isolated in regard water supply although it is in a common growth area as other seedlings. I don't want to lost this seedling as Phal bellina is one of my favourites

[Ray]

How long has it been in semi-hydroponics?

What is the formula of the fertilizer, and at what concentration are you using it?

Tell us about your water supply.

Is water ever standing on the leaves?

[OzPhal]

Thanks Ray for your reply...

About the plant - it's been in S/H for about 6mths now. It came from S/H, was transported in wet sphag and spent a few weeks in that, and was then put back in to S/H. It has thrown up two new and very nice leaves in that time.

The fertilizer components are:

%w/v
Nitrogen 1.29
Phosphorous 0.31
Potassium 1.01
Calcium 1.00
Magnesium 0.40
Sulfate 0.15
Iron 0.031
Manganese 0.00925
Boron 0.0021
Zinc 0.0020
Copper 0.0010
Molybdenum 0.0005

I'm making it up at 15mL per 1500mL

The water supply is straight tap water from Melbourne, Australia (it's not overly hard). The only thing that could stand on the leaves is water from the humidity although i never notice wet leaves. There has been the occassional droplets that have landed on this plant when i take the lid off (water condenses on the underside of the glass lid when it's quite humid in the tank)

Any thoughts?

[OzPhal]

Any help would be appreciated - i really dont want to lose this beauty

[nheidar]

Does anyone have the answer to this question? I have the same problem:



I recently got a compot of two Phal bellina. They were both in the same little 2 inch pot in sphag, so same conditions.

Unfortunately, one of the phals started to lose one or two of its leaves a couple days after I brought it home, but I didn't think much of it because they were bottom leaves. The way it happens is the leaf slowly starts to yellow from the tip, and it spreads until the entire leaf is dead. Today it lost its last full leaf (one remains that is about halfway mature).

Its roots are very hardy and green (which is also why I originally thought nothing of it losing leaves). There are no other signs of stress, no spots, nothing else that I can think of or see. The other phal is doing great with new roots on the way and very quick growth.

In an attempt to discover if there is an issue with the deeper roots, I unpotted it; but there is nothing wrong with it. [FYI: I put it in its own pot with hydroton in s/h -- I understand that this may cause extra stress, but I just did it anyway in hopes that something different would be a good thing, since its original conditions were not doing it any good.]

Does anyone know how I can salvage this bellina, or what is wrong with it?

These pictures were taken a few days ago, before the last yellow leaf fell off.

Thanks,

Natasha