The Endo type mycorrhizal fungi, also known as VAM for Vesicular Arbuscular
They are generalists which means that any species of Endo can associate with any plant species with only modest differences in who favors who.
The spores of the Endo type mycorrhizae are huge in comparison to the Ecto type and are not airborne like the Ecto’s. Being so large they also do not move easily through the soil, since the soil’s porosity is smaller than the spores, therefore putting them on the surface does not work very well.
The way to use them is to dust the seed before planting or dust the roots of transplants before planting. The spores need to be in direct contact with the seed or the root of the potential host plant.
Again, dusting the spores dry onto the seed or the roots is the best way to use a mycorrhizal product.