Rootshield aka trichoderma harzianum

[Lars Kurth]

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

Hi all, I´ve recently been experimenting with trichoderma harzianum which is a parasitic fungus that seems to work rather like a symbiont, it protects the plant roots from fungal and bacterial pathogens and as well enhances the performance of the plant. It´s marketed as RootShield in the US ...

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

[doraagritech]

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

[Ray]

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.