Abnormal mottling on Paph. Druid Spring

[CMW]

Hello!

I've been reading for a while, but this is my first time posting, so everyone

I have a small (ha!) collection of about 60 plants that I grow indoors under lights. Anyway, I bought this Paph. Druid Spring (which is druryi X primulinum I think?) at a local orchid show in Spring of 2013. It was in bloom when I got it.

A few months later, these white chlorophyl-lacking areas appeared quite rapidly. As of now it is putting out new growths, and these too show are mostly white.
Any idea what it is? Disease, mineral deficiency?

(I attached a couple pics but I'm not sure if they stuck).

Thanks for any info!

[billc]

Welcome. I have a Maudie type that occasionally will have a leaf exhibit something similar to what you are describing. I don't know what it is and since it's only that one plant, once in a while I don't really pay much mind.
Take a look at these sites even though they don't seem to cover exactly what your issue is.

Diagnosing Orchid Problems

Orchid Diseases

Bill

[jeremyinsf]

Is it possible your plants are getting way too much light? The one next to it looks pretty bleached also.

[CMW]

Could be; I am growing them on the bright side. All my paphs have been getting progressively yellower and sadder over the last couple of years (new growth green, yellows as it matures; old growths yellowing and dying pre maturely), and I am beginning to suspect that they may have a Calcium deficiency/overabundance of Potasium?

I am moving my paphs over to S/H culture too, since I've figured out that I've been growing them too dry. My growing area is in my laundry room, in the same room as the furnace, so the advice to "water less in winter" doesn't quite apply! I'm thinking a steady source of moisture instead of a moist/dry cycle will help. And I can see clearly when they need to be watered.

The mottling on the Druid Spring occurred quite quickly, over the span of a week or so. The plant was being displayed in an East windowsill with only dappled sun. A mystery! As long as it isn't a virus, I'll let it be for now and see how the new growths come out.

[jeremyinsf]

Can you tell us more about your lighting situation? I get they are under lights, but, what kind, how far from the lights, and for how long each day?

What kind of fertilizer are you using?

[CMW]

They are under florescent tubes, 3' long. One 'warm white' and one 'cool white.' The tops of the plants are about 12" away from the lights. Right now they are getting 12 hours of light, and the time will be increased a bit come spring.

I am using the MSU fertilizer, R/O water formula (and I water with R/O water I get in 5 gallon refills from the grocery). I fertilize once every other watering, at about half strength. Less often in winter, of course.

[jeremyinsf]

Do you know what kind of tubes? T5? T8?

That may very well be too close, for too long. If they are T5, I can almost tell for you for sure that it is.

Do you have a light meter, or a light meter app on your phone?

[CMW]

They are T8, 25 watt tubes. I don't have a light meter pr an app for one, but I suppose it wouldn't hurt to check. I always figured that since I've read to keep the plants 6" away from the lights, or as close as possible with light loving species, that my lights were far enough away. Maybe that's not the case.

[jeremyinsf]

Originally Posted by CMW

They are T8, 25 watt tubes. I don't have a light meter pr an app for one, but I suppose it wouldn't hurt to check. I always figured that since I've read to keep the plants 6" away from the lights, or as close as possible with light loving species, that my lights were far enough away. Maybe that's not the case.

I use T5 so I can't speak to T8, but I know the light levels are much lower anyway.

I learned with my lighting that what I read didn't always apply or was current. I burned plants at 6" away.

Highly suggest the free light meter apps - you can search on this board for threads specific to that.

[Orchid Whisperer]

Originally Posted by CMW

They are under florescent tubes, 3' long. One 'warm white' and one 'cool white.' The tops of the plants are about 12" away from the lights. Right now they are getting 12 hours of light, and the time will be increased a bit come spring.

I am using the MSU fertilizer, R/O water formula (and I water with R/O water I get in 5 gallon refills from the grocery). I fertilize once every other watering, at about half strength. Less often in winter, of course.

Hi CMW

I'm not sure - does the CMW formulation provide Ca and Mg? In Central IL, your tap water might provide adequate Ca and Mg, or you can add some to your RO water. (1) CalMag of some type, or (2) provide dissolved gypsum (1 tsp/gal) + Epsom salts (also 1 tsp/gal), add a few ounces of this solution per gallon of your RO water.

As others have suggested, my bet is on too high a light level. Symptoms of Ca deficiency typically show as new growths that blacken; I don't think that is it. I have read that Mg deficiency can lead to prematurely yellowing leaves, though; easily fixed with Epsom salts.

Good luck with it, hope you can fix the problem!