Zygo Trouble
 

I'm having some trouble with my Zygos. The leaves start with brown or black spots, then yellow and drop off of the plant. I've been reading about different ailments, but I can't seem to narrow it down. This is my second Zygo with this issue, the first lost all of its old leaves, but retained its pseudobulbs and new growth shoots. I have attached pictures of the second plant with the problem which seems to be attacking all leaves of this plant, but not the bulbs.

Any help or recommendations for treatment are appreciated!!

do you wet the leaves when watering?
I soak the pot in a basin for 5 min. weekly or if the mix dries up....preferrably let it be moist but not soaking wet....
they have thin sensitive leaves that are prone to cold water spots(dark spots created when exposed to shaded sun=that will attract fungi if its not treated); the yellow rings on pic 2 is fungi and it can be sprayed with hydrogen peroxide ....
also look for mites and scales that will tend to infest them

Sorry for not providing more background. The plants are watered from below, so the leaves don't get wet (no misting either). I haven't' been able to find any pests on either plant and surrounding plants seem fine. They are windowsill grown with ~60% hum 65-85oF temps and have seemed very happy until August when the first started to drop all of its leaves, now this one...

I have read that Zygos get spots on the leaves when they are over-heated. They don't like an excessive amount of heat or sun although mine get quite a bit of sun. I try to keep them cool and give them good moving air. I bought one from Paramount a year ago that had little spots all over the leaves and by growing it cooler all the new growth has no spots. I would try some sulfur powder on the spots to stop it from spreading or some other fungicide.

I should add that I only have one bloom size and one smaller one so I don't have a lot of experience with them.

on picture #2 the yellow rings around the black spots is fungi....you may spray it with peroxide

I had the same thing happen to my Zygolum Louisendorf, bought it in full bloom, but when the new growth unfurled it's leaves, they seemed sticky and then slowly turned that same color. It bloomed anyway, but the leaves dried up and died. Same thing happened to the following growth. It only kept the leaf on the oldest bulb.

A grower in the Toronto area told me he had the same thing happen to a batch of Zygonisia Blue Birds and to other plants of his in the Zygo family. He told me the change the media and soak the whole plant in a Physan 20 solution. It's what worked for him, even if he never knew exactly what the cause was and no other plants ever had the same issue. I did it for my zygo and it pushed a new growth and the leaves seem normal this time!

I also water it by soaking the plants in a bucket for a while. I think getting water on the new growth by accident might be what caused that for me. And, because I am a very bad person and I soak several plants in the same bucket, I think whatever fungus this is might be targeting Zygos only if that's at all possible? None of my other plants caught this and I had to have shared that water with phals and catts before I noticed the problem.

My solution, Physan spa treatment :) Whichever fungi is the bane of our zygo leaves doesn't like it at all.

silken - at first I did think this was overheating as they were in the hotter of my growing spaces. I moved them to the cooler, fan-ed area and the disease kept on progressing.

sithwitch - This is exactly what is happening and the plant in the picture is a Zygo Louisendorf. I gave it a Physan bath last night, I really hope that's enough to stop this nonsense.

Thank you all for your help!

I have the same zygo, Louisendorf. It did this when I switched to the new fertilizer (MSU-type) from my former system (Ironite, powdered milk, Epsom salts, Better-gro orchid fertilizer). Could it be nutrition or pH related? I am still experimenting with this idea. Adding the ironite and calcium back into the mix seems to be having a positive effect. If anyone figures out the perfect way to grow these....