Fungus Bacteria or Sunburn - Dendrobium kingianum
 

Hey all, thoughts on this? Have used Mancozeb three times on it hoping it wasn't fungus but really don't know.

Top side: No issue
http://i1299.photobucket.com/albums/...psb98b5443.jpg
Bottom Side:
http://i1299.photobucket.com/albums/...ps4d39f00b.jpg

And whilst I'm here, can anyone confirm spider mites and suggest a treatment? Have tried sulphur and mineral oil, maybe need successive doses of both.

http://i1299.photobucket.com/albums/...pse457bb33.jpg
And a microscope image I got of one of the little fellas, he is well under 1mm, maybe 0.25mm.
http://i1299.photobucket.com/albums/...psa1e3f6d7.jpg

Certain that it's a mite. The damage looks like spider mite damage.

Unpot, clean the plant really well. I would discard all of the medium & re-pot in new medium. Treat with a product that is labeled to treat mites. Try the Bayer 3-in-1 product (labeled as including a miticide), or you can try a Neem-based product.

Thank you! I thought it was mites, started treatment but i'll keep it up til they dont come back.

Any thoughts on the brown splotches on the D. kingianum?

I can't help with the den but am giving you a bump.
Joann

The brown spots are a fungus spread by the spidermites…

Ah ok, so it's a type of fungus. I'll make sure it doesn't spread and keep the mancozeb up if it recurs. It's got 4 new canes at the moment so it's kicking along ok.

Mites often infest plants that are otherwise stressed, by dry air, heat, standing air. So you have to question your growing conditions.

Fungus Bacteria or Sunburn - Dendrobium Kingianum
 

Yes, caused by spider mites. Dendrobiums are very susceptible to them when humidity is low and temps are warm. That's exactly what mine had a couple of summers ago. I grow indoors and can't use chemicals so I kept washing the leaves and their undersides with Dr. Bronner's Hemp Eucalyptus Castille soap to keep it in check but the damage was done. The brown's leaf damage, it won't revert. So not pretty but the plant survived. Check your growing conditions.
Here's what my plant looks like right now and no mites in sight.
http://img.tapatalk.com/d/14/04/02/upenyqu4.jpg

Yeah its been pretty rough down here the last few months, have had many days over 40 degrees c (104f) so have been misting daily (twice some days) to keep the humidity up. Should get a bit easier going into winter. Thanks for all the help! P.s thats a beautiful flower! Cant wait for mine!

Sounds familiar.
Thank you and best of luck.