This spotting is insane

[Bamanana]

Several months ago I purchased Den. Firewings (12 canes) from a seller in Hawaii that couldn’t get it out of the pot, so he cut down the side of the pot and deeply into the dehydrated rootball. I whined and he said, of course, “trust me, I’ve been doing this a long time.” So it languished and developed bizarre spots on leaves before they dropped with only green spots left on yellow orange leaves. It finally gave up the ghost and I pitched it. I really wanted a Firewings, so I ordered one from a Louisiana nursery that sent me a pristine orchid with new growth that I planted in semi-hydro. (Yes, the previous one also went into semi-hydro because I was new to SH and didn’t catch the new growth thing in all the info I sifted through.) It is crazy that this new plant is developing the exact same spots. I do not share any water whatsoever and none of my other dendrobiums and orchids are affected. Is this something that only Firewings do? Will it snap out of it? Do I need to take some action? What the heck is this? See picture.

[SADE2020]

Ohh..

Looks like a puccinia fungi, and after that incident if desinfection didn't ocurre It may definitely be a fungi. Let see what the seniors says, but I would bet a fungicide treatment and quarantine will be the advice.

Good luck!

[estación seca]

What are your temperatures/humidity? How much light are you giving it? How are you watering? Describe your S/H pot, medium, the holes you drilled. Was it actively making new roots when you moved it to S/H?

[Bamanana]

Temp 70ish, humidity 60%, moderately bright light, flushing biweekly, glass vase with two holes drilled about 1/3 way up, hydroton, it had several new roots starting.

---------- Post added at 06:36 PM ---------- Previous post was at 06:31 PM ----------

Additionally, the first Firewings did not get that dry brown patch. Just the yellow leaves with the bright green spots with the tiny divot in the middle. This pic is the only leaf with the brown dry patch.

[estación seca]

This is a hybrid in Dendrobium section Latouria. They should never dry out completely. Letting them dry out once often causes significant leaf fall. Many people who grow them in pots with standard medium put the pot in a dish with a small amount of water at all times.

I would water a Latouria newly moved to S/H as often as necessary to keep the old root system moist, and keep this up until the new roots grow down into the always-moist zone. You can water once a day in S/H without causing problems.

I'm not sure whether lack of water is causing everything you are seeing, but drying out a Latouria can cause this. Healthy plants aren't as susceptible to fungal attacks as are stressed plants.

I'm actually in the process of establishing a Den. rhodosticta (section Latouria) and a Den. forbesii (section Formosae) in S/H. Both arrived bare-root. I put them into S/H immediately, and have watered so the roots never dry out. For me that has been every 1-5 days, depending on the weather.

[Bamanana]

Thanks! I keep it moist, but it dried some in shipping. The first one that died was bone dry when I received it. So do you think this is stress related and not some king of crud? I sure do appreciate all you helpful people on this board!

[estación seca]

Lack of water causes leaf drop on this kind of Den. I don't know what fungi live in your area. I don't know whether the water stress weakened the leaf enough for fungus to attack. In my grow area I have temperatures and humidity like that during winter, and I've never seen a leaf like that.

Are there any orchid societies near you? You could ask somebody nearby whether they recognize this.

[Shadeflower]

No a dendrobium should not do this.
It looks like an infection over a water issue.
The first seller introduced this into your home whatever it is and I also think you need to disinfect everything.
It will carry on living on living tissues and moist surfaces.
Any affected leaves need to be disposed of.