Black spots on Zygo leaves and yellowing on a NOID

[Kethry1313]

Hi, I introduced myself earlier in the intro thread and said I would be coming here with a question about my mom’s Zygo. Syd Monkhouse. Here are the pictures of it. What are the black spots and how do I get rid of them? Thank you for any help.





I also have a NOID that I believe is an Oncidium. It's leaves are turning yellow with brown spots.

[Lagoon]

Welcome to the forum Kethry

I don't grow Zygos, but I do grow oncids.
With the zygos is seems to be a pretty commen problem as I've heard from others who grow these.
I don't believe there was much you can do about most of those spots.
Sorry I couldn't help - maybe someobe else can.

The oncids do get black spots, but they should be very small and NOT spreading - many of mine have spots from higher lighting. I've accepted oncids and their spots, some always seem to be there no matter what.

Your yellowing leaves maybe a sign of your bulbs becomming - 'back bulbs', they will in time become leafless - it's normal, leave them.

[Ross]

On the Oncidium, I believe this is a common thing steming from spray the leaves while it is growing. They, typicallicaly don't like this. The yellowing could be from old back leaves or from lots of light. Neither is is cause to worry. The black spots might mean you want to quit spraying the leaves (if you doing this).

[Kethry1313]

Thanks for the information, Lagoon. I'll keep an eye on it to see if that's what's going on.

Ross, I only recently started spraying them because of the black spots. I had read somewhere else that the spots might be caused by too little humidity, so I put it in a tray filled with rocks and water making sure to keep the bottom of the pot out of the water. I'll stop spraying though. Thanks for the info.

[Ross]

Rocks and hunidity don't cause the spots. Only the spraying. Keep up with everything EXCEPT the spraying

[dave b]

The leaf you were holding with the large brown area needs attention. Cut it off an inch or two below the discoloration. Could be pythium bacteria (soft brown rot), so wash your hands and the cutting utensil afterwards. Actually, use alcohol and or a flame to sterilize the utensil before and afterwards. I'd then sprinkle cinnamon on the end of the cut to ward off infection.

Water getting on the leaves, cool temps near the window, and too low of air flow increase the spotting. Especially with the pythium.

[hayesraceing28]

My oncid/odontoglossum not sure which it is but I am not sure what to do with it. It has a bunch of black spots all over the leaves and look to be spreading at a pretty quick pace. The tips of the plant are turning into brown/black lesion like places on them.

[King_of_orchid_growing:)]

I recommend just leaving your Zygo alone. I grow one, and they do that if they're not acclimated to a certain growing location. Particularly if they were grown in a greenhouse, then they get moved outdoors.

It's no biggie. Subsequent growth will produce disease resistant leaves, and eventually the new leaves won't do it anymore. The old leaves will drop, then the spotting will be nothing but a faded memory.

It just looks ugly at first that's all.

[Maryanne]

Try spraying with Neem. I spray my Zygos and Oncidiums - such as Shari Baby - several times a year.
Neem is a natural oil from the neem tree, whihc has been used for centuries by Asian Indian people.
It is a mild pesticide and fundgicide.

It won't cure the already exisiting black spots, but will reduce the number of new spots on newly emerging leave greatly.

Good Luck ~
Maryanne

[Angurek]

Keep an eye on that brown spot on the zygo. If you notice that it's spreading, you can cut off the affected part and, as someone on this thread mentioned, sprinkle the lesion with cinnamon. I've tried that with some of my plants and it seems to work reasonably well.

Good luck. I hope your plants grow and bloom for you for many years to come.