Agriculture Reference
In-Depth Information
Fig. 8.3
Schematization of the ecological theory of compost suppressivity based on the interac-
tive coevolution between the microbial community (
M
) and their trophic niche or environment
(
E
) that occur dynamically in a determined period of time. The suppressivity results from the sum
of the effects of simple and complex microbe-to-microbe (
I
), microbes-to-environment (
II
) and
environment-to-microbes (
III
) interactions, in each timeframe (
0-i
)
8.5
Compost Suppressivity in Integrated Pest
Management
Thus, compost-based suppressivity can be considered a successful tool for disease
management only through a new ecological and global vision of the agriculture. In
order to potentiate the effectiveness of compost phytoiatric applications, the integra-
tion with other control methods is desirable. Additional suppressive factors is often
indispensable because they improve efficiency of compost, extending the spectrum
of controlled pathogens and prolonging the time of protection. For example, the
compost could be actually fortified by combining it with the incorporation of vari-
ous microbial antagonists, which contribute with their specific mechanisms (Sid-
diqui et al.
2008
). Trillas et al. (
2006
) used cork compost enriched with the Spanish
strain T-34 of the bio-control agent
Trichoderma asperellum
as plant growth media
for protecting cucumber seedling from Rhizoctonia disease. Similarly, the addi-
tion of a compost-derived isolate of
Trichoderma harzianum
significantly increased
the ability of rice straw and empty fruit bunch null-effective compost extracts in
controlling
Choanephora
wet rot in okra production (Siddiqui et al.
2008
). Same
bio-control formulations prepared by amending a paddy straw compost whit singles
antagonistic cyanobacteria isolates, such as
Anabena oscillarioides
(C12) and
Ba-
cillus subtilis
(B5), proved more effective in reduction of tomato diseases caused
by a plant pathogenic fungal consortium including
Fusarium oxysporum
,
Pythium
debaryum
,
P. aphanidermatum
and
Rhizoctonia solani
(Dukare et al.
2011
). Forti-
fication of composts with antagonistic microbes seems to be a suitable strategy of
integrated biological control. However, the effectiveness levels depend by the com-
post type and the plant pathosystem, as demonstrated by using antagonistic isolates
of
Verticillium biguttatum
and non-pathogenic
F. oxysporum
in various bioassays
(Postma et al.
2003
).
