[APWG] Allelopathic chemicals, Dr. Stebbins, and warning about test plots

[Craig Dremann - Redwood City Seed Company]

Dear Wayne and All,

Thanks for your emails.

If you check Google Scholar, there are a lot of articles about plant
allelopathy. For example, a good one is The allelopathic phenomenon, a
dynamic process. By Francisco A. Macías, Alberto Oliveros-Bastidas, David
Marín, Diego Castellano and José M.G. Molinillo

http://www.regional.org.au/au/allelopathy/2005/1/2/2647_maciasfa.htm?print=1

This article has details about the natural herbicide-like chemicals
involved, phenols and benzoxazin.

Regarding Dr. Stebbins, there is a list of his papers in chronological
order that I posted on the web when I was co-authoring some native grass
technical papers with him, before he passed away in 2000.  You can see the
list at http://www.ecoseeds.com/stebbins.html

Yes, Dr. Stebbins did find that some populations of native grasses do
produce sterile seeds, especially within some groups.  Elymus, Sitanion,
Bluebunch wheatgrass are populations in the West where that can be found,
but probably only one out of every 100 populations of plants.

It is easy to check for sterile seeds, if you just take your fingernail
and if you do not feel anything hard, the seed did not form.

One of the most interesting papers, that Dr. Stebbins and I published in
1998, is that there are 100 more species of native grasses to be
identified and named here in California.  The 300 current described
California native species were named by physical features in the 1800s
before taxonomists knew about genetics and chromosomes.  Now we need to
tease out of those 300 species of grasses, 100 more, based on chromosome
counts, because they are separate species.

A WARNING about small scale test plots.  While you are sowing your native
seeds in amongst the weeds, at the same time, you absolutely need to set
up two EX-SITU TEST POTS.

What you do is get two 8 inch diameter plastic pot and scrape off the top
inch of soil from the weed site, and fill up one of your pots to within
3/4 of an inch of the top.  In a second pot, you fill it with a commercial
potting mix, I personally like Miracle Grow Organic Choice or their Orchid
potting mix.

Then, at the same time that you sow the native seeds, you also sow some of
the native seeds into your two plastic pots, and take those pots back to
your home or office to keep an eye on.  Give them the same conditions as
your test plot site.

You are doing this to check for soil problems.  If the native seeds grow
in the commercial potting soil, and do not thrive in the weed-soil, then
you may have soil problems.

I was teaching classes to the California Dept. of Transportation
(Caltrans) and the Delaware DOT in 2000 about replacing the roadside weeds
with local natives, and the results of planting in Ex-situ Test Pots was
one of the exercises, that you can see at
http://www.ecoseeds.com/good.example.html

You can see all the Natives for Roadsides DOT training exercises at
http://www.ecoseeds.com/natives.html

And never, ever be the least bit discouraged if your test plots fail the
first time.  Or the second time, or even the third time.  It took UC Davis
three tries and $450,000 to get their native test plots to work and not
get completely eaten alive by the weeds, that you can see at
http://www.ecoseeds.com/road.test.html

Sincerely,  Craig Dremann (650) 325-7333