Fungus?

[Kevinator]

Hey guys. Kevin here. I recently inspected my Pescatorea dayana to find these spots on the leaves. Not only that, the new growth browned and died! Is this thing some sort of fungus? Temperatures are in the high 60's and humidity is 50%. I've been keeping it moist and it has a spike developing. I feel that more spots are appearing. Is there any way to treat/prevent this?

[King_of_orchid_growing:)]

It's possible it's fungus.

This is one of the reasons I don't really like growing Pescatorea, Chondroscaphe, Chondrorhyncha, Huntleya, or any of the other "pseudobulbless" Zygopetalinae in full moss. Rotting out happens far too easily with this potting medium for this group of orchids.

I think they do far better in coconut husk chips, imo. Just my .

[lepetitmartien]

Pic 1, I'd say fungus (see guignarda/phylosticta on Sue Bottom's pdf on STAUG)

Pic 2 has a mechanical damage turning bad, maybe the same as the upper spot, upper spot looks nasty, now I'm not sure what it is. If oozing liquid (contagious) and stinky, it's bacteria. If you're lucky, a fungus will smell fungus.

Avoid any water on leaves, whatever it is, it'll spread with water. I'd cut the leafs, apply cinnamon on cuts and apply Bordeaux mixture. Maybe peple more acquainted with Pescatorea will have a better option.

[King_of_orchid_growing:)]

This is going to sound like it's contradictory advice, but it really isn't if you consider where they come from in the wild…

Increase the air circulation to not just the leaves, but the roots as well while maintaining a decent humidity level and a good amount of moisture for them. This is why I mentioned the CHC, so that the potting media can retain water while providing the orchid with plenty of air.

Btw, they do awesome at around 85% humidity, but it isn't necessary.

[Leafmite]

Here is the link to the Sue Bottom site:

http://www.vaos.org/vaosblog/wp-cont...SueBottom1.pdf