Harpin Protein

[dice]

One thing about spores of mycorrhizae and similar products:
if you start early enough, you only need a little bit for each
plant.

I have some MycoGrow Soluble left from last year, and what
I have done is measure it out with a tiny measuring spoon
that holds about half-a-pea's worth of whatever is in it (came
in a set of tiny measuring spoons with quantities like "pinch,
dash, smidgen," and so on). Then I sprinkle that over the roots
of a seedling when potting up the first time.

It will populate the root system and grow right along with it,
and that should be all that the plant needs for the whole
season.

If I were inoculating thousands of seedlings, this would probably
be too time-intensive, and I would either mix it into the
container mix that I was using or mix it with water and water
it in after potting them up instead.

Dusting it on the seeds when starting them would need even
less per plant, but my initial watering is with a mild hydrogen
peroxide solution, which would probably kill off the beneficial
fungi and bacteria as soon as they hatched. By the time that
I am potting up from seed starting cells to larger pots, the
hydrogen peroxide has all reacted with other materials in the
seed-starting mix and is no longer an issue.