Undergrounder, just for clarification on the diseases I mentioned, black spot on roses and black rot of orchids -- they’re both fungal infections. You’re probably thinking of bacterial brown rot.

Yes i was thinking of bacterial rots, although they can be black as well.

Have read that tricoderma is used on corn corps both on seeds before they are planted and as a spray after growth. Could that be the reason it is common in corn meal? It is said to promote root growth and encourage Nitrogen uptake as well as preventing bad funus attack.
Have found a Biotech company that offers tricoderma both in the liquid and powdered form. They are sending me a sample. Have a covered test of wet corn meal in the greenhouse - my wild bird seed got moldy due to wet conditions so added a sprinkling of that to the corn meal. When the tricoderma gets here and the corn meal gets moldy will spray the surface and see what develops. Also have a few orchids that would go in the trash - there are culls from a flask. Will apply the tricoderma and observe the result.
Am seeing some opinions that tricoderma may attack other pathogens than just fungus.

Thanks for posting this very interesting thread. Plant-fungi relations are one of my specific interests and this might make an interesting topic or project in one of my horticulture classes.

Very interesting stuff, but the thought of putting something into the medium that absolutely will decompose quickly (compared to the medium) would seem to be a concern for limiting root zone aeration.

Can't wait to find out what happens with those experiments, orchids3!

I don't know about the Trich on cornmeal thing, but i would hope that there isn't green Trich. mold spores all through the cornmeal we are eating? I know its supposed to be harmless, but ... blleeccchhh!

Florida is full of mold spores. We are a wet humid semi tropical to tropical place. A lot of people have respatory problems due to this condition. Organic matter decomposes so fast in gardens that the only way to get nutrients to plants is with fertilizer addatives. Even gardening in the ground! A chemist friend of mine says we really use hydroponics. Organic matter decomposes very quickly and is useless as a soil ammendment. To try to understand the process that is going on is only natural.

Trichoderma harzianum in orchids
 

Hi there! I have been using weekly trichoderma harzianum for the last 2 years and I have seen a really better performance in survival, height and root zone of my cattleyas seedling including those recently deflasked.

Trichoderma have good effect on controlling fungus diseases，promoting root growth and improve soil contion. Especially Trichoderma harzianum T-22, testing reuslts is very good.

That species is well known for its effects, but that does not mean that all trichoderma species are beneficial.

Relying on ubiquitous species is playing Russian Roulette.