sun burn?

[ikotka]

Howdy,
I have two orchids my mom saved from a Trader Joe's last year. I babied them to the best of my inexperienced ability and so far so good I think. This Vuyl. Melissa Brianne "Tawny Tart" got some spots on it summer of last year and I ruled (from online searching) that it was just sun burn. It has been doing fine, no spots or critters on the underside of the leaves. But now a new shoot is growing, I think they're called pseudobulbs (???) and the centers of each new leaf also has the brownish/black spots. However, it seems to be growing fine, new leaves, new roots, no spike/inflorescence yet - but i'm hoping one will come from the new growth. Can anyone confirm that the spots are just sun burn?

Also, my MIL cut the leaves back (without asking) in a V shape and I about died. I know that when cutting orchids you have to use precaution to avoid bacteria. The shears she used are kitchen/garden shears, and I did not put anything on the leaves when I found out. Any suggestions or should it be fine as is?

Thanks!!!!

BTW here's a pix. you can see a new little growth at the bottom too.

[kmarch]

The new growth looks healthy and of a good colour, so at the very least the plant is headed in a positive direction. Also the pseudobulbs look plump and pretty healthy so that's good.

I have never seen spots on a leaf as yours seem to have. I've seen bacterial spotting from beign too humid or wet and too cool, but they are black and sunken anddon't look quite like your spots.

It looks like the leaves responded unfavorably to something that was sprayed on them. Or perhaps something was sprayed on them then they got too much sun. I'm not really sure. I'm curious and eager to see of other members have seen this kind of spotting before.

[articuno75]

I agree with Kmarch. The leaves look really good in color and the bulbs look fine. What I do want to ask is do you mist your plant?

Oncidiums can develope a fungus from misting. I have to dig in my files for the article and I'll post it.

I still mist all of my Oncidiums and other orchids, but I promote good air circulation for prevention of fungal growth.

[jay]

I have a couple of Oncidium type orchids with spots like this on the leaves. It doesn't seem to bother the plants as they continue to put out new growths and flowers.

[Hummer344]

I to have spots on Onc Sharry Baby. I just live with it. It isn't dystructive at all.

[articuno75]

I've got black spots on my leaves, what are they?

This is generally a leaf rot caused by types of fungi that are commonly classified as Cercospora or Colletotrichum. Many times this rot will start out as yellow spots, gradually turning to a brown or black colour. Note that certain plants such as most Oncidium hybrids often get several small black spots on the leaves due to the sun. In this case it is natural spotting and will not harm the plant.

The best kind of treatment for this problem is to use a bactericide or
fungicide spray such as Phyton 27. After treatment, examine to see if the spots are increasing in size or number within a 7 to 10 days. If you have successfully cured of the problem, the spots should dry up and turn brown. If there are still signs of new rot, repeat treatment. Leaves that are heavily covered in rot should be completely removed. Make sure you sterilize whatever tool you may use to remove the infected leaves with as it can spread the disease to other plants.

This is a copy from simply-thai.com. I cannot find my article, but this mentions the same thing. I know that Oncidiums are more prone to these bacteria, especially with misting, and especially the mule ear types. Thus with misting air circulation is stressed and encouraged.

[evagentry]

The spots look simular to the ones my zygo has , have you tried a little less light?

[ikotka]

Thanks for all the input!! I haven't tried more light - it's in the same spot as my Phals, and continually has new growth, so I guess I'll leave it alone and continue on the same path. Thanks all!
Beca

[clarita]

Looks like oncid."Freckles" to me. If so that is a sign that the plant has been well light.