Rootshield aka trichoderma harzianum
 

Hi everybody,
on the UK Orchid forum a forum member made the following comment recently:

I was wondering whether this is something any of you have experience with?

As I know, The main function for Trichoderma harzianum is controlling soil-borne diseases, Root promotes and soil conditioner.

It can protect roots away from harmful fungus in soil.

Reference: Trichoderma Harziahum bio control

Such beneficial fungi do predate pathogenic ones, but also actually help the plant take in water and nutrients.

As the rhizosphere is colonized, the fungi extend a hyphae network throughout the potting medium, which acts as a "root" system for them. They also extend mycelia that penetrate the plant's roots. Together, they absorb water and nutrients from the entire mass of potting medium - far more broadly than the plant's roots reach - and "pump" them directly into the plant.

Some species of beneficial bacteria also predate pathogenic ones, and in the process of replication, exude antibiotics that prevent infection, as well as root-growth stimulating hormones.

If you do some digging, you'll find a fair number of formulations that contain beneficial fungi or beneficial bacteria, but rarely, both.

Could be worth a shot testing out with your orchids. There is some research that shows benefit to orchids and there are some products I could find that have two species of trichoderma. Root shield is expensive!

Trichoderma Based - Mikro-Root

Sounds like a sourdough starter - the goal of which is to create a balanced environment of yeast (fungus) and lactobacillus and acetobacter (bacteria). In that case, the biggest factor driving equilibrium is the temperature its kept at and what kinds of sugars are available to eat for the yeast. Less effect of the initial innoculant. I suspect there will be a similar role of temperature in orchid media.