Weird green bullseye on my Den Findlayanum . . .

[blackvine]

Does anyone what this could be? It appeared rather suddenly - one day after I put it from about 18" from a T5 light, at an angle, to 6" under the light. I moved it back again from the under the lights immediately, when I saw it today. Honestly, it could have been there before the move, but not more than 3 or 4 days ago. The whole leaf turned yellow, except for that odd green circle with a brown "bullseye" in the middle. Another half one at the edge of the leaf. What could it be?

[WhiteRabbit]

[blackvine]

Thanks, Sonya! I think I've stumped my OB friends . . .

[NYCorchidman]

There were a few threads on this symptom of dendrobiums in the past, and no one knew what it was.

I call it "the mystery ring disease". I hate it because usually the appearance of this ring is the beginning of the demise of the affected plant.
I'm not saying yours will die, but mine did. lol

[blackvine]

Originally Posted by NYCorchidman

There were a few threads on this symptom of dendrobiums in the past, and no one knew what it was.

I call it "the mystery ring disease". I hate it because usually the appearance of this ring is the beginning of the demise of the affected plant.
I'm not saying yours will die, but mine did. lol

Nooooooo! Oh, I hope not!

[NYCorchidman]

I did not mean to freak you out, but I did. lol

As long as this stays confined to just one or two leaves, then I wouldn't worry.

When this hit mine, it either caused the entire cane shed leaves in a short time, or I would trim the affected leaves, but the ring would keep coming back, eventually leading me to trim all the leaves. lol

So either way, it was a losing battle for me and I dumped the plants. Mine were both phal type hybrids.

One is now replaced, which is dendrobium Sonia, and it is super healthy.

The other one was a unique art shade, but oh, well...

The good news is that there are always so many exciting dendrobium hybrids out there in the market for me to choose from.

Oh, ok, I just remembered that I do have one nobile hybrid, Country Girl, which had one or two leaves with this ring, which I stripped off the cane last spring.

I have never seen it since.

So there you go, some hope too, right?

[blackvine]

Yes, thanks, NYCorchidman!

[Bloomin_Aussie]

I've seen this a few times and in my opinion it is an immune response of the plant to avoid spread of infection. It simply stops nutrient supply at the base of the leaf so the whole lot yellows. Not sure why the green ring. Possibly the fungus or bacteria is breaking down the leaf and producing sugars that temporarily sustain the surrounding tissue. In my experience the green doesn't stay around for long.

[blackvine]

NYOrchidman, I do see two threads with pics that look very similar to my issue: http://www.orchidboard.com/community...endrobium.html

http://www.orchidboard.com/community...endrobium.html

Bloomin'Aussie, that makes sense! I don't think the viral/fungal attack was serious because the rest of that particular plant as well as all the rest of my plants are perfectly fine. I just cut the leaf and threw it out.

[Phal-lover]

I have this on my Onc. Incurvium... It's only on one and a half leaves. (there's only half a ring on one) However so far the plant's healthy and growing two new psedobulbs. Hopefully yours and mine will live!