Oncidium Firecat Harmony - Black Outer Edges of Lower Leaves

[realoldbeachbum]

Once again I come asking for diagnosis/treatment.

This Oncid has been in my care for around 6 months. It bloomed beautifully for 2 months in an East facing window in the dining room (low humidity, 75-80 F temps, and normal Oncid watering - damp not soggy).

Today when I unpotted it from the tiny pot it was purchased in, I found good roots, but black outer edges on the lower portions of many growths. (The black is only along the outer edges of the leaves.) The pbulbs are fine and roots are many and look healthy in 100% spagh. The center roots were still embedded in the foam plug from its seedling days.

What to do? Should I try to cut the outer edges of the leaves? Treat with something -- what? Ignore it and repot in new spagh?

Album — Postimages

Thanks so much for your advice! ROBB

[SADE2020]

The Oncidiums have a point where despite receiving the "indicated" water, it seems that they are receiving more than necessary and sometimes fungi arrive. Also if you try to cut those sheets or layers in the bulb and leave small wounds the plant has more propensity to get infected.

If it were my plant; when I am in doubt, I would do an antifungal treatment with 2 applications, the second being 20 days apart from the 1st.

I see you have it unpot; another thing they don't like not having a medium, the deterioration is rapid when they go downhill. The report should be done quickly; fast.

[estación seca]

I think that's normal for older leaves on older growths. I would repot and not worry about them.

[OrcishOrchids]

Maybe try not to let the moss touch the base, mine hate having water anywhere besides the roots.
(P.s. My oncidiums get these all the time, but they don't seem to do any harm)

[Ray]

I agree with ES. Nothing to be concerned about. Those will be the first leaves to be lost anyway, as the plant matures.

If it becomes too much for you to mentally handle, just rip those leaves off.

[realoldbeachbum]

Thanks Sade, es, OO, & Ray. I feel better now. Will fungicide it, then repot a little "HIGHER" in new spagh.

Ya'll are the BEST!!! ROBB

[estación seca]

I would not use fungicide unless you regularly have known fungus problem in the space where you grow this orchid, and you know the fungus you have is susceptible to the fungicide you use. Even at the temperatures you mentioned fungus would be rare in a home unless the relative humidity is too high for human comfort.

Fungicides kill beneficial organisms as well, organisms that inhibit the growth of pathogens. Instead I would recommend using a mixture of beneficial organisms. They are often sold as mychorrhizal fungi but they include beneficial bacteria. I still have some Inocucor in my refrigerator, which is no longer sold in the US. When that runs out I'll get some of Ray's beneficial organism product.

[realoldbeachbum]

Originally Posted by estación seca

I would not use fungicide unless you regularly have known fungus problem in the space where you grow this orchid, and you know the fungus you have is susceptible to the fungicide you use. Even at the temperatures you mentioned fungus would be rare in a home unless the relative humidity is too high for human comfort.

Fungicides kill beneficial organisms as well, organisms that inhibit the growth of pathogens. Instead I would recommend using a mixture of beneficial organisms. They are often sold as mychorrhizal fungi but they include beneficial bacteria. I still have some Inocucor in my refrigerator, which is no longer sold in the US. When that runs out I'll get some of Ray's beneficial organism product.

So es, I suppose I will NOT go the fungicide route. I have Quantum-Total on hand. Does that serve as beneficial bacteria? If so, all is well. If not, what is the name of the product that Ray sells?

Thanks millions!! ROBB

[estación seca]

I have not used Quantum-Total, but this is the kind of product I mentioned. I trust Ray's judgment, and when I have run through my Inocucor I will get some of that.