if you go to Google groups at
http://groups.google.com/group/rec.gardens.orchids/
and search the archive of this newsgroup for the term "microfungus" you will
find threads in which the term has been mentioned as far back as 1995. I
don't think anything conclusive has ever been posted about it and I tend to
think of it as a kind of 'internet' lore, because I have not been able to
find anything written about it anyplace else. I have even asked a few
agriculture extension agents I know... None of my text books on botany or
pest management mention it, but they all talk a lot about fungus problems.
And most fungus diseases that infect living plant tissue are microscopic so
the term is somewhat confusing and misleading to begin with and probably
applied a bit loosely when nothing else seems to apply...

Whenever this term comes up I wait to see if somebody can post something
definative.

"van" wrote in message
oups.com...
I was talking with an orchid grower today who warned me about a problem
that orchid growers seem to be having, but don't know much about it or
what to do. It is called a microfungus and once it sets in it
eventually kills the orchid. It spreads very easily throughout a
greenhouse or collection and affects phrags, paphs, phals, and other
things. Small brown or orange lesions appear mostly on the undersides
of leaves and discoloration eventually spreads killing the leaf or
entire new growth or eventually the plant. Healthy established plants
may have the microfungus symptoms but still grow and bloom.
Apparently not much is known about this and there is no known cure.
Phyton 27 may help control it but it never seems to go away. One West
Coast commercial greenhouse operation apparently lost an entire
greenhouse orchid collection to what was attributed to this mysterious
"microfungus."

Anyone know more about this "microfungus?"

Thanks