Black freckles on Dendrobium.

[Linton]

About a month or two ago, I bought a phal type Dendrobium at Ikea with what I think is some black scarring on some of the leaves. The plant was in bone dry sphagnum for several weeks but I kept going back and looking at it and eventually just had to rescue it, despite not being sure what the black spots were from.

When I got home and repotted, it turned out to be two separate plants growing in little coconut husk blocks, wrapped tightly in the sphagnum. The plant on the left seems to be in fine shape besides some older dehydrated canes, but one of the smaller canes on the other plant has been developing small black freckles in addition to the larger black spot that I thought was just scarring of an abused plant.










Is this a virus or infection of some sort, or is it related to the dehydration the plant went through? Should I cut off the smaller freckled leaf?


On the bright side, I have a cute new growth.


I'm still new to orchids, so thank you in advance for your help.

[RobS]

Besided the spots on the 4th pictures they seem harmless to me. The 4 picture with the group of spots on the leaves is something I haven't seen before on an orchid. Did you try to wipe them of? Are they raised on the surface of the leaf?

[Linton]

I also wasn't worried until the spots in the 4th picture appeared.

The large black spots are sunken in like something damaged the leaf, but the freckles seem to be discolored inside the leaf. They don't go through to the bottom of the leaf, but they're not raised and they don't scrape off.

I would have removed the leaf already but I don't want to do that and forget about it if there's something more drastic I should be doing.

[Zdenglan]

These look like either bacterial or fungal leaf spots to me..I have them myself on some of my dens and I regard it as fairly normal but I guess a spray with Physan20 wouldn't do any harm...

[Linton]

That makes me feel better, thanks a lot. I don't have any physan and don't know where they carry it, but I suppose I could order it online.

[RobS]

If the spots don't get worse don't spray. Sparying chemicals almost always has a slight negative effect on a plant. Personally I only use chemicals on soft rot and scaly and wooly bugs.

[Zdenglan]

I agree with RobS, if it's not serious, I tend not to use it, however it's handy to have it just in case, you can easilly get it on ebay for instance..