RE: [compost_tea] early blight in tomatoes

From: Tom Jaszewski <tomj_at_livesoil.com>
Date: Mon, 10 Feb 2003 01:01:35 -0800


Basilios Papageorgiou, Jürgen Helbig, Carmen Büttner:
Ability of Watery Extracts of Composted Organic Waste from Urban Households
to Control Airborne Plant Pathogens

[*]
<http://mars.wiz.uni-kassel.de/tropentag/proceedings/2002/html/#foot5474>
BASILIOS PAPAGEORGIOU, JÜRGEN HELBIG, CARMEN BÜTTNER
Humboldt University Berlin, Institute of Horticultural Sciences, Germany

The effect of compost applications on plant health has mainly been
investigated regarding soil borne diseases. The few investigations on the
effectiveness of shoot treatments with watery compost extracts showed that
leaf pathogens were effectively controlled and that different mechanisms
seemed to be involved. Additionally to systemically acquired induced
resistance, some other antagonistic mechanisms of the microorganisms present
in compost extracts were observed, including production of antibiotics,
concurrence for nutrients or parasitism. In the present investigation, the
effectiveness of watery extracts from composts that were produced from
organic household waste in West Africa, was examined using the pathosystem
tomato and Alternaria solani.
Applications of watery compost extracts successfully suppressed infection of
A. solani on tomato. Different factors were checked for their impact on the
effectiveness of the extracts and the density of microorganisms present in
the extracts. Temperature and frequency of stirring significantly influenced
the density of microorganisms and the effectiveness against A. solani. Daily
stirring of the compost-water mixture during the extraction period (3 days)
increased the density of microorganisms sevenfold and disease incidence was
reduced by [27]% as compared to the treatment with only one initial
stirring. The incubation of the compost-water mixture at [20]C increased the
number of microorganisms in the extract tenfold as compared to mixtures
incubated at 30 and [35]C. The extract incubated at [20]C reduced incidence
of A. solani by [66]% as compared to the control, whereas the other variants
were less effective.
The formulation substances cellulose, alginate and xanthan were added to the
extracts to increase their effectiveness against the pathogens. The extract
enriched with xanthan reduced disease incidence on tomato by [23]% as
compared to the extract without formulation substances.
Storage duration of the composts after their preparation significantly
influenced the density of microorganisms present in the extracts and their
effectiveness against A. solani on tomato. Those composts that were stored
for a shorter period showed a higher number of microorganisms in the extract
and a higher effectiveness of the extracts


Tom Jaszewski
www.livesoil.com
702-595-7012

-----Original Message-----
From: Ross Orner [mailto:rorner_at_pennswoods.net]
Sent: Sunday, February 09, 2003 7:28 PM
To: compost_tea_at_yahoogroups.com
Subject: [compost_tea] early blight in tomatoes

Does anyone have any experience with the effects of compost tea on early
blight on tomatoes? This is a problem disease for a producer in New Jersey
conditions.
Thank you,

Ross Orner
www. ornerfarms.com

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Received on Mon Feb 10 2003 - 11:42:52 EST

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