IAS Aroid Quasi Forum

About Aroid-L
 This is a continuously updated archive of the Aroid-L mailing list in a forum format - not an actual Forum. If you want to post, you will still need to register for the Aroid-L mailing list and send your postings by e-mail for moderation in the normal way.

  RE: Harmful Fungus in Sphagnum Moss?
From: Ron McHatton rmchatton at photocircuits.com> on 2001.06.21 at 19:36:27(6798)
When the use of sphagnum moss as a potting material for orchids caught
on some 15 years or so ago, one of the first issues to surface was the
purported presence of spores of a fungus which could be contracted by
humans. The physical manifestation of infection is the formation of a
round cyst like object deep within the skin which works its way slowly to
the surface and breaks open releasing spores. These cyst like objects are
typically about half the size of a pinhead or so although in some published
cases they are quite large and apparently bothersome. There was an article
illustrated with pictures published in the American Orchid Society Bulletin
some years ago (if you would like a copy, I could probably locate it).
That article demonstrates being able to culture the spores from virgin as
well as used wet moss. This launched the scare that had a lot of people
sterilizing their moss, working with impermeable gloves and surgical masks
or for some people even respirators around the moss. What wasn't reported
publicly (very well anyway) was subsequent work which demonstrated that the
same fungus can be cultured from anything we use as potting material, even
things like Fafard 3B and Promix. Infection in humans is possible (as far
as I am aware, only through an already existing wound), but it is extremely
rare and apparently not worth the effort worrying about and bottom line is
that you can get the same infection from any material, fir bark, promix,
sphagnum moss, coconut husk chips, etc. I have been growing orchids for
something like 37 years, and I am more worried about the dust from dry
perlite and the little slivers of bark than fungal problems.

Ron McHatton

Note: this is a very old post, so no reply function is available.