[APWG] What caused surprise results in Poppy Project?

[Robert Layton Beyfuss]

I have nothing against pots but they do not accurately represent what physically happens in field or forest soils when it rains. Any container will adversely affect the drainage of a field soil, resulting in very different soil moisture levels at different depths within the container compared to the real world. This is true whether the pot  is 12 inches or 2 inches deep, six inches or 6 feet wide.  This is called a "perched" water table. The drainage holes at the bottom of pot channel the water above them to the holes, resulting in wetter soil for a longer time then if the water drained naturally through the field soil. Pathogens that cause the complex known as "damping off" thrive at higher moisture levels. Pots tend to keep those pathogens in the immediate vicinity of the seedlings where they may or may not kill them. These fungal pathogens are widespread in all soils. I don't know how you can rule out damping off. Did you have them tested by a pathologist?

________________________________
From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of craig at astreet.com [craig at astreet.com]
Sent: Friday, September 13, 2013 9:50 PM
To: apwg at lists.plantconservation.org; craig at ecoseeds.com
Subject: [APWG] What caused surprise results in Poppy Project?


Dear Robert and All,

Sorry you don't like pots?  How about a one foot by two foot flat that is four inches deep, as an ex situ test pot?

You can see that same result in two flats at http://www.ecoseeds.com/good.example.html.

Not damping off,  in either case.

Sincerely,  Craig Dremann (650) 325-7333







> Hi Craig
>
> Putting soil in pots changes the entire ecology of the experiment. I hate
> it when people do pot studies on plants that are growing in natural
> settings and try to extrapolate that data into the real world. Your plants
> most likely died from damping off, a common complex of fungal pathogens
> that is most virulent in containers and much less so in the real world.
>
> Bob
>
> ________________________________
>
From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of
> craig at astreet.com [craig at astreet.com]
> Sent: Wednesday, September 11, 2013 1:41 PM
> To: apwg at lists.plantconservation.org; craig at ecoseeds.com
> Subject: [APWG] What caused surprise results in Poppy Project, where
> seedlings all died?
>
>
> Dear All,
>
>
>
>From my Poppy Project in Palo Alto, California, (Google = Poppy
> Project+Arastradero) I took soil samples from under the poppies where
> they had been shedding seeds this summer from locations 10 feet apart, and
> put the soil into 4 inch plastic pots.
>
> I watered the pots and within a few weeks, had a lush growth of poppy
> seedlings in both pots. Both pots were side-by-side evenly watered and
> neither were fertilized.
>
> However, within a month, every single poppy seedling in one pot died, and
> you can see a picture of both pots at
> http://www.ecoseeds.com/what-difference.jpg.
>
> These pot-tests of checking soil samples from the future revegetation
> sites have become the standard for Caltrans for their projects, ever since
> I taught them classes on the use of native plants 13 years ago, to
> discover and correct this problem.
>
> This is the second time I have encountered this very important issue in
> such a dramatic way that is often overlooked, when trying to get native
> plants established here in the West---so any guesses of what the
> difference was?
>
> Sincerely, Craig Dremann (650) 325-7333
>
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