What is the conversion rate from growmore to plant matter?

Yes, I already know that there is no such thing as that but ..., in an
ideal situation for each gram on growmore how much plant matter will be
produced? - assuming that no other nutrients are limiting. I want to
know the theoretical maximum.

I use growmore on my garden vegetables and I usually put it around each
plant, half a teaspoonful at a time.

So, for instance, what is the most growmore I should give each
individual parsnip or strawberry plant?