Re: [tomato] light, not heat

Louis Mensing (
Thu, 4 Mar 1999 09:20:31 -0800

-----Original Message-----
From: margaret lauterbach <>
To: <>
Date: Thursday, March 04, 1999 7:49 AM
Subject: [tomato] light, not heat

Thanks Margaret for this information.

>"The bottom line, say mycorrhizal researchers, is that if you already have
>healthy soil that contains a lot of beneficial microorganisms, you probably
>won't derive much benefit from mycorrhizal inoculants.  If you have just
>moved to a new development where the topsoil was replaced with fill dirt
>and construction debris, mycorrhizae may be beneficial if used in a program
>of organic soil amendments and if use of pesticides and quick-release
>synthetic fertilizers is kept to a minimum....

Researcher Dr. Robert Linderman and others have spent a great deal of time
studying Easter lilies on the southern Oregon/northern California coast.  He
found that cultivation and phosphate (super phosphate) suppressed
mycorrhiza.   There is evidence that different species of fungi produce
different responses.  Most commercial innoculants provide combinations of
different species for just that reason.   What I have in my home garden may
or may not be the most benificial.  Also, I want the mycorrhizal established
on the roots even before I transplant my plants into the garden.  (Timing
obviously makes a difference re the direct seeding posts)  The mycorrhizal
relationship takes about two weeks to become established.  We usually see
the results of fertilizing in an additional two weeks (unless we use foliar
applications...which make a much more rapid response).

"(Michael) Miller of Argonne National Laboratory says, 'Under most
>gardening conditions, you have mycorrhizal fungi already present in the
>soil.  You have to have the appropriate fungi to get the optimum response
>from different host plants.  Unfortunately, with most commercial
>inoculants, you don't know if it's going to work...."

Yes, most soils have mycorrhizal fungi present.  Are the most benificial
species present?  Commercial innoculants usually contain species that have
proven valuable in tests.  There are regional differences and differences
even in one's own gardening area in the species of mycorrhiza present.

I might also be well to remember that unless there is big money behind a
product...whether it is vitamins, medicine, or in this case 'home garden use
of mycorrhiza' it is not going to get the funding to do the tests.  Somehow
I don't believe my 17 tomato plants are high on any researcher's list!

Then too I believe that for a couple of dollars I am willing to see if using
innoculant make a difference on my soil and plants.  That is the ultimate
test.  Either I choose to try the innoculant or I don't.  At least now I can
make that choice...five years ago I couldn't (as the product was available

An interesting research report, beyond 'will my tomatoes do better' is
and also

Louis Mensing
Eugene, OR