[permaculture] Re: a herbicide for organic agriculture perhaps
Lawrence F. London, Jr.
lfl at intrex.net
Sun Sep 22 16:15:17 EDT 2002
Subject: Re: a herbicide for organic agriculture perhaps
Date: Sun, 22 Sep 2002 13:32:40 +0800
From: David Menne <menne at IINET.NET.AU>
To: SANET-MG at LISTS.IFAS.UFL.EDU
Followed this up as the subject of trying to move towards safer herbicides
is always of interest to me. Even more interesting was that
"In fact, the knapweed leads a bizarre existence by producing two mirror
images of catechin. One form, known as negative catechin, is the
plant-killing poison, while its mirror twin, positive
catechin, kills off disease-causing bacteria in the soil."
Might need to be careful regarding first assessing any significant effects
on the Soil-Food-Web ?
In any event regarding the allelopathy :
1. Found that Centaurea maculosa is not poisonous : " it is consumed by
livestock [only when other vegetation is unavailable]. The plant releases a
toxin that reduces growth of forage species.
2. It is described [for us aliens unfamiliar with this weed - although I
notice in New South Wales it falls into the highest Weed Category, must
report & fully destroy] on :
3. Agrimonia eupatoria L. (Agrimony, Sticklewort) might be a better source
It has "Long used as a substitute for tea in Europe", and might be grown as
a value-adding byproduct of forestry as a high-value speciality crops are
cultivated under the protection of a forest canopy that has been modified
and managed to provide the appropriate conditions(*) - providing short-term
income while high-quality trees are being grown for wood products.
[This is suggested on http://www.agroforestry.co.uk/forfarm.html so
obviously the alleopathy does not harm the trees ? And replacing the full
sun noted as a requirement elsewhere is not critical ?]
(*)The amount of light in the stands is altered by thinning, pruning, or
adding trees to achieve 5-40% crown cover.
The estimable Jim Duke notes that Agrimony contains 2.6% catechin in the
whole plant [easier to harvest than roots] - also notes very useful
quantities of Ursolic Acid which is very much a medicinal cure-all; should
one start putting up extraction plants and equipment.
In any event, agricultually one might not extract the Catechin - instead,
lay "hay" on the ground for it to leach into the weed root zones ?
AGRIMONOLIDE Plant: DUKE1992A
ALPHA-AMYRIN Plant: DUKE1992A
APIGENIN-GLUCOSIDE Plant: DUKE1992A
CATECHIN Plant 26,000 ppm; DUKE1992A
CATECHIN-TANNIN Leaf: DUKE1992A
CERYL-ALCOHOL Plant: DUKE1992A
COUMARINS Plant: DUKE1992A
ELLAGIN-TANNIN Leaf: DUKE1992A
FAT Seed 350,000 ppm; DUKE1992A
GALLO-TANNIN Root: DUKE1992A
LUTEOLIN-GLUCOSIDE Plant: DUKE1992A
PALMITIC-ACID Plant: DUKE1992A
QUERCETIN-GLUCOSIDE Plant: DUKE1992A
QUERCITRIN Leaf: DUKE1992A
SILICIC-ACID Exocarp 120,000 ppm; DUKE1992A
STEARIC-ACID Plant: DUKE1992A
TANNIN Leaf 50,000 - 80,000 ppm DUKE1992A
THIAMIN Leaf 2.4 ppm; DUKE1992A
TRITERPENES Plant 15,000 ppm; DUKE1992A
URSOLIC-ACID Plant 6,000 ppm; DUKE1992A
David Menne : http://www.plantsfood.com
"We can't solve problems by using the same kind of thinking we used when we
created them" - Albert Einstein (1879-1955)
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