[APWG] Allelopathy knowledge can save a lot of time whenweeding+restoring areas

[Wayne Tyson]

I'd like to be brought up to date on allelopathy research. "Back in my day," 
there was C. H. Muller at UCSB and another guy at UCB who argued the issues 
back and forth a lot. Steve Lincoln did a master's on one of my very early 
projects (1968-69), but didn't come to any conclusions that would be useful 
(in my view, at least) in ecosystem restoration practice. The problem then 
was, as it often is in ecological research, too many variables. The 
"chemicals" needed to be identified; perhaps they have been, and have been 
demonstrated to be effective in lab tests. Muller noticed that, for example, 
where cows rolled in stands of black mustard, recruitment of indigenous 
species would occur, so he had a graduate student roll around in some of his 
study plots. This might be analogous to laying the straw down, but I am not 
certain whether or not other factors (other than "chemicals") are 
involved--or, for that matter, not a significant factor at all.

WT

"There are strange things done in the midnight sun, by the men who moil for 
gold . . . " --R. Service

PS: Olivia, I have long been "unsubscribed" from rwg too, through no act of 
my own . . . I don't know that I need to be.


----- Original Message ----- 
From: "Ty Harrison" <tyju at xmission.com>
To: "Craig Dremann - Redwood City Seed Company" <Craig at astreet.com>
Cc: <apwg at lists.plantconservation.org>; <rwg at lists.plantconservation.org>
Sent: Friday, August 26, 2011 10:53 PM
Subject: Re: [APWG] Allelopathy knowledge can save a lot of time 
whenweeding+restoring areas


> Craig et al.:  It will be interesting to see the results of your Nasella 
> pulchra straw mulch on the germination of the exotic annual weeds in Palo 
> Alto.  Might I suggest scattering the straw prior to the soaking fall 
> rains which trigger the annual's germination, rather than waiting for them 
> to germinate and then applying the native grass straw mulch.  I think that 
> allelochemics work in various ways (both germination inhibition as well as 
> radicle growth inhibition) but I suspect that having the germinating weed 
> seed exposed to the chemicals leached into the soil during the germination 
> process may give better control.  This is like the classical alllopathic 
> seed germination assay tests on moist filter paper but doing it in the 
> soil (microbes and all).  Regards,  Ty Harrison
>
> ----- Original Message ----- 
> From: "Craig Dremann - Redwood City Seed Company" <Craig at astreet.com>
> To: "Craig Dremann - Redwood City Seed Company" <Craig at astreet.com>
> Cc: "Ty Harrison" <tyju at xmission.com>; "Craig Dremann - Redwood City Seed 
> Company" <craig at astreet.com>; <ialm at erols.com>; 
> <apwg at lists.plantconservation.org>; <rwg at lists.plantconservation.org>
> Sent: Saturday, August 20, 2011 10:34 AM
> Subject: Allelopathy knowledge can save a lot of time when 
> weeding+restoring areas
>
>
>> Dear Ty and All,
>>
>> Knowing which native plant give off the strongest herbicides and which 
>> are
>> the strongest weeds, can make you weeding life so much easier, and you 
>> can
>> have the native plants help you as allies in your efforts.
>>
>> For example, yesterday I drove 400 miles round trip, just to pick up a
>> single bale of Stipa native grass straw, Nassella pulchra, whose straw
>> contains one of the strongest herbicides of our native grasses.  It was
>> like buying a 5 gallon bucket of Roundup in a bale.
>>
>> I am working on some test plots in the hills of Palo Alto, a beautiful 70
>> acre canvas that is currently solid exotic grasses, and I want to see 
>> what
>> can be done, to get it back to 99.5% native plant cover.
>>
>> So in test plots last year, I looked at the interaction between adding
>> fertilizers to modify the weed cover, and also adding California poppies,
>> that you can see photos at http://www.ecoseeds.com/arastradero.html
>>
>> The ideal situation is if you are left with any weeds, you want to get 
>> all
>> perennial rye plants, rather than any wild oats, ripgut, blando, foxtails
>> or zorro grass, because the perennial rye has the weakest herbicide
>> effects of the six grasses.
>>
>> So what I am going to do, is wait until the first rains bring up the weed
>> seeds, scatter a thin layer of Stipa straw on top of them, add poppy 
>> seeds
>> plus fertilizers, and wait 3-4 months and see what I get, like baking a
>> cake but it takes a little longer.
>>
>> What I am hoping for is no foxtails, zorro, ripgut, blando, or wild oats,
>> maybe <5% cover of perennial rye and 95% cover of the poppies.  Then next
>> autumn, start sowing in the local native grass seeds, like the Stipa
>> itself.
>>
>> So I am going to give the weeds a double dose of allelopathy, first with
>> the Stipa straw, then with the poppy plants producing it in their roots--
>> especially effective against annual grasses.
>>
>> You can think about this allelopathy issue, as the land is one big giant
>> petri dish.  And all the plants, all of the natives and all the weeds, 
>> are
>> each giving off herbicide-like chemicals like antibiotics at a greater or
>> less amount.  We need to go out and see what the relationships are, and
>> use them to our advantage.
>>
>> Many of our Endanagered plant and animal species in the West are 
>> grassland
>> species, and knowing which weeds are the most toxic against the native
>> plants, and knowing which native plants are the strongest against the
>> weeds, can help save a lot of time and effort when managing or recovering
>> those species.
>>
>> Sincerely,  Craig Dremann (650) 325-7333
>>
>>
>>
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>
>
>
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