Definition from wkipedia:
A mycorrhiza (Gk.,: fungus roots, pl mycorrhizae, mycorrhizas) is a symbiotic (generally mutualistic, but occasionally weakly pathogenic) association between a fungus and the roots of a vascular plant.
In a mycorrhizal association, the fungus colonizes the host plants’ roots, either intracellularly as in arbuscular mycorrhizal fungi (AMF), or extracellularly as in ectomycorrhizal fungi. They are an important component of soil life and soil chemistry.
Soil & Organics: I use Mycorhizae in my Hum-tea creating a rooting juice much like Root Accelerator or Hygrozyme for my soil, also I add 3 tablespoon per yard of soil I mix.
Hydroponics & Aeroponics: this is where I need a fine granular to keep from clogging so I would use Great White or possibly Plant Success’s also makes a cheap fine granular, but if not grind it to a powder it works. And I add a teaspoon for every 5 gallons of water. Do not add hydrogen peroxide with this because it will kill all the myccrohizea.
Well today as I was in one of Oahu’s growing and gardening shops geared more towards our needs, when I was moved to ask another customer how he was going to use the product he was buying, Plant Success Great White( premium grade). In so he was asking if he should dust the top of his soil pots with it, in my advice I changed his purchase from great white 4oz. $42 to Hydro Organics rooters myccrohizea $12 for 3 times as much and better to blend in soil, also Plant Success makes cheaper versions. I have used Great White but only in hydro and aeroponics, which a fine powder helps from clogging. But I could suggest a coffee grinder to do the same thing for fractions of the cost. So be frugal and understanding why and how we use each product helps a farmer be efficient and cost effective. Buy for your purpose farmers!