In article ,
Chris Hogg wrote:
On Wed, 10 Jul 2013 18:21:30 +0100, "Bob Hobden"
wrote:
"Emery Davis" wrote

The thing about mycorrhizae is that you need a pretty great whopping lot
of it for a tree that size, and the stuff is expensive.

I'm surprised at that. Never used the stuff, but I would have thought
that being a fungus, provided the soil conditions were favourable and
not hostile to it, the fungi would increase and multiply once the soil
had been inoculated by even a fairly small amount. After all, it's not
like a fertiliser, that slowly diminishes with time as it's used up or
leached out. The Rootgrow FAQ says "If you under-dose colonisation
will be slower maybe 1-2 months rather than 2-4 weeks", which makes
sense. Perhaps AT was aiming for long-term soil improvement rather
than instant effect.

You are right. From the Web site, it's hard to tell where on the
snake oil to miracle compound spectrum that is. They do say that
mycorrhizal fungi are host-specific, but don't give much of a
clue as to which plants would benefit, and their implication is
that their mixture is suitable for most plants. That sticks in
my gullet from what I know about mycorrhizal fungi. Also, some
mycorrhizal fungi can be pathogenic under some circumstances!

I didn't see a reference to a controlled experiment, either, though
there is at least one in progress:

http://www.sustainable-edale.org.uk/.../introduction/


Regards,
Nick Maclaren.