Pale new leave on Paph Little Alexander...

[Kavanaru]

I have two plants of this same cross, both growing under exactly the same condition. However, one of them (just the one starting a spike ) is loosing color on the newest leave. You can compare the plant on the photo, and see the old "healthy" darker green leave and teh newest pale & reticulated ones...

Does anyone knows why this could be happening? How could I solve this?

Note: The rootsystem seems to have no problem... lots of new roots (already checked )

 

[PaphMadMan]

You didn't tell us anything about your fertilizer program, but it looks like a nutrient deficiency - calcium, magnesium, iron, etc. Could just be showing up in this plant because it is working to make a spike.

 

[Ross]

My first impulse would be to slightly reduce the light on this one. If it's under florescent lights, put it toward the end of the bulb where the light level is lower. I would be watchful, but not overly concerned. The next step would be to repot. Although both Alexanders are in the same media, maybe something is just slightly different in the pot of the yellowing one. I've repotted yellowing plants that looked otherwise healthy, and they have responded with even more root growth and healthier looking foliage. With the plant well established in a semi hydro mix, though, maybe a series of flushes with pure water might eliminate any possible salt build up in the mix. I might try this first.

 

[goldenrose]

I'd give it a shot of epsom salts & slightly reduce light.

 

[Kavanaru]

Thanks a lot!!! I water all my plants with RO water and fertilize every second week with Peters Excel for pure water (13-5-20-7 CaO-2 MgO): 1 week fertilizer, 1 week pure water). For my calcareous Paphies I also add Dolomit to the medium, however, since this is a cross of a calcareous (helenae) and a non-calcareous (gratrixianum) I did not add Dolomit (assuming that the needs for Ca and Mg would be covered by the fertilizer... Maybe, I should add some Dolomit to this particular plant (??)