[compost_tea] Comfrey study abstract

From: Ryan, Matthew <matthew.ryan_at_rodaleinst.org>
Date: Fri, 20 Feb 2004 15:47:12 -0500

Hi Everyone,

Here is some background on comfrey tea for disease suppression.

 Antifungal activity of aqueous extracts of the leaves of cowparsnip and
comfrey.
Karavaev, V. A.; Solntsev, M. K.; Yurina, T. P.; Yurina, E. V.;
Polyakova, I. B.; Kuznetsov, A. M.
Department of Physics, Moscow State University, Vorob'evy gory, Moscow
119899, Russia.
Biology Bulletin of the Russian Academy of Sciences , Volume: 28 ,
Number: 4 , Page: 365-370 , 2001
translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya (2001)
No. 4, 435-441 (Ru)
Language: English

Abstract: We found that extracts from the leaves of medicinal comfrey
(Symphytum officinale) and cowparsnip (Heracleum sibiricum) strongly
inhibit the germination of Erysiphe graminis conidia and uredospores of
Puccinia graminis. Spraying wheat seedlings with these extracts, in
contrast to the irrigation of soil, markedly diminished infection in
plants with powdery mildew. Antifungal activity in vitro and protective
activity (when plants were sprayed) correlated with the level of
phenolic compounds in these extracts. Experiments with healthy plants
demonstrated that the photosynthetic apparatus of wheat plants was
stimulated by extracts. Spraying seedlings with the extracts resulted in
an increased rate of O2 evolution calculated per unit of chlorophyll, an
increase in the ratio (FM-FT)/FT in the experiments that recorded slow
fluorescence induction, an increase in the relative light intensity of
band A, and a decrease of relative intensity of band C in experiments
with thermoluminescence of wheat leaves. These results provide evidence
that the protective activity of comfrey and cowparsnip extracts is
associated with their action on the pathogenic fungus and with the
activation of natural defence reactions of the host plant. (31 ref.)

Subjects: antifungal properties conidia defence mechanisms fungal
diseases in vitro leaves medicinal plants oxygen phenolic compounds
photosynthesis plant diseases plant extracts plant pathogenic fungi
plant pathogens wheat Araliales Heracleum sibiricum Erysiphe graminis
Heracleum Puccinia graminis Symphytum officinale Triticum Triticum
aestivum Field Crops, (New March 2000) Viral, Bacterial and Fungal
Diseases of Plants, (New March 2000) Pesticides and Drugs; Control, (New
March 2000) Non-food/Non-feed Plant Products

CAB ABSTRACTS
(c) 2004 CAB International. All rights reserved.
Dialog(r) File Number 50 Accession Number 4127329







Received on Fri Feb 20 2004 - 19:26:33 EST

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