What are these spots?

[KristenReuel]

This Bifrenaria harrisoniae is under attack by something. It is only affecting the newest leaves, so I assumed it was a fungal infection, and sprayed it with a fungicide. But the new leaf that was hit the hardest kept getting worse quickly and the leaf has now dropped off. This leaf in the picture is the last new leaf on one of the two new psuedobulbs. There is no sign of infection on the other older leaves at all.

The marks are slightly pitted where there is black/brown, and all of the marks are clearly visible from the front and the back of the leaf. What is it, what is the best course of action, and should I cut this leaf off completely?

Thanks for any info!

[Luizacft]

I don't know what it is, but I'd check for virus infection.

[KristenReuel]

I just found this

Leaf and pseudobulb diseases on Bifrenaria harrisoniae (Orchidaceae) caused by Phyllosticta capitalensis in Brazil (PDF Download Available)


There is a picture very similar to what mine looks like. Apparently it is a fungus that is difficult to treat? Great.

[LizB88]

I had a plant with similar marks, and anti fungal did not work to eradicate, and brown Listerine worked, don't ask me why, I just know that I wash my plant with Listerine, let it sit for a few minutes, them spray clean water and if I do this once every 6 to 7 weeks, I don't see any spots on the leafs.
I think I'm starting to sound like a commercial for regular Listerine, but it works in keeping my plants healthy, so I have bottles of the stuff!

Good luck and hope you find something that works for your plant.

[KristenReuel]

I have heard of the brown listerine before! Do you wash the whole plant, including the media?

[LizB88]

Originally Posted by KristenReuel

I have heard of the brown listerine before! Do you wash the whole plant, including the media?

Yes, you wash the whole plant, including the media. Just make sure you let it sit for a few minutes and then wash the plant again.

I have used other fungicides on already infected plants, and don't know why regular Listerine seems to give me the best and fastest results.

[KristenReuel]

Thank you! I will go regular listerine hunting today