Catasetinae leaf chlorosis and curl?

[Dorchid]

The one cat I’ve been watering is growing well but the leaves aren’t unfurling as quickly as I would have expected. They’re also a bit chlorotic on the tips...just a slight mottling. It’s getting fed a tsp/gal of 20-20-20 a couple times a week with a flush every fifth watering and may be a tad close to the lights but the leaf is cool to the touch. Thought?

[SouthPark]

The leaves appear to have dimples across it. Just monitor the orchid closely. If the leaves begin to all yellow, then check the roots - to ensure that the sphagnum isn't overly wet.

[Dorchid]

The sphag stays damp and never completely dries out as I was under the impression that’s how they like it. The medium to plant/root ratio is also very low as it’s in a 4 inch pot. Not sure if this is what you’re referring to as dimples, but a couple of the plants have these bumps on them. The plants are right under a very strong COB fixture with 2 chips, so, I’m thinking they may simply be getting blasted and I should increase the distance between them.

[Roberta]

You can't water Casetenae too much when they're in active growth. And they benefit from high fertilizer levels as well though twice a week of 1 tsp per gallon sounds a little on the stiff side, I'd really be thinking "spider mites" - the underside of the leave that I see has the "stippling" or silvery quality that is their signature. And Catasetinae are spidermite magnets. Some of that damage could also be from being too close to lights, but when in active growth these also need a lot of light so I doubt it.

[Dorchid]

The only pest I can find are fungal gnats. I’ll back down to half tsp fert and raise the lights. Appreciate the input, all!

[Roberta]

Remember, spidermites are microsopic. Difficult to see even with a magnifying glass, a jeweler's loupe maybe. You can try wiping the underside of the leaf with a tissue or piece of cotton soaked in rubbing alcohol. A reddish residue would be the tipoff.

[Dorchid]

🤔 No luck with that. Also, the plant right next to it shows none of the same symptoms and none of the other plants are showing any damage either. Can’t see anything under the loop either. I’ll keep an eye on them. Thanks for the tips!

[SouthPark]

Apologies dorchid. I should have written pimples instead of dimples. Those bumps. Those close-up shots may even suggest that condition that somebody mentioned in one of the recent posts --- edema or something, which is apparently benign or not harmful.

But those checks for spider mites etc was well worth the effort. Totally agree that spider mites can be dynamite or explosive on catasetums.

If there's some chlorosis, could maybe give a little mag-cal treatment.

[Dorchid]

Thanks, SP! Yep, looks like edema. Seems strange as I don’t keep them sopping wet and it’s also on one that hasn’t been watered yet.