Compost Teas: 24 hour, EM, IM, BD & fermented plant extracts

[Steve Diver <steved AT ncat.org>]

Effects of water extracts of a composted manure-straw mixture
on the plant pathogen Botrytis cinerea

World Journal of Microbiology and Biotechnology
Issue: Volume 10, Number 1
Date: January 1994
Pages: 20 - 26

http://dx.doi.org/10.1007/BF00357556


M. P. McQuilken, J. M. Whipps, and J. M. Lynch

Microbiology and Crop Protection Department, Horticulture
Research International, Littlehampton UK


Abstract

Manure-straw mixtures were composted and water extracts,
made by incubating compost in water for 3 to 18 days, were
assessed for antagonistic activity against Botrytis cinerea,
using a range of tests. Extracts of all ages inhibited conidial
germination on glass slides and reduced mycelial growth on
agar. Mixing extracts of all ages with droplets of suspensions
of B. cinerea conidia on detached Phaseolus bean leaves
suppressed lesion development, but only 3- to 8-day-old extracts
had an effect when sprayed onto leaves 2 days before inoculation.

Extracts contained a large and varied microbial population of
actinomycetes (0.3 to 2.4×10(5th) c.f.u.ml–1), bacteria
(1.5 to 5.6×10(10th) c.f.u.ml–1), filamentous fungi
(25.0 to 45.5 c.f.u. ml–1) and yeasts (26.1 to 62.6 c.f.u.ml–1).

Eight- and 18-day-old extracts lost activity completely on filter
sterilization or autoclaving. Weekly sprays of 8-day-old extracts
onto lettuce in the glasshouse had no effect on the incidence of
grey mould, but significantly reduced its severity and increased
marketable yield. The use of compost extracts in biocontrol of
plant diseases and their possible mode of action is discussed.

Key words: Biocontrol - Botrytis cinerea - compost - compost extract


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