Agriculture Reference
In-Depth Information
frequent rainfall and heavy dew favour spore germination. Temperature and water
activity of the host are the fundamental factors that affect fungal growth inside grain.
DON synthesis is mainly influenced by temperature and water ativity and its production
seems to play a decisive role on the aggressiveness of
F. graminearum
and
F. culmorum
:
it has been suggested that in the presence of DON, plant defence mechanisms are not
triggered fast enough, thereby leading to an increased aggressiveness of the pathogen.
The accumulation of DON in the grain is intimately related to the development of the
disease in the field. Prevention strategies through pre-harvest agronomic management can
achieve the quality and safety standars required by the market and international
regulations. Among the agricultural practices, FHB development and DON
contamination in wheat grains are mainly affected by tillage, crop rotation, varieties and
fungicide application. None of these strategies on their own are able to significantly
reduce the impact of this disease. Nevertheless, careful planning of all the different
management decisions canl lead to the designing of crop management systems able to
reduce FHB and mycotoxin incidence and severity. In other words, it is necessary for
producers to make use of the available wheat varieties that are known to be more resistant
and to apply all of the good agricultural practices tuned to a determined cultivation area.
Useful tools for prevention are represented by FHB and DON predictive models: the
use of a model to predict the outcome of a disease is desirable to enhance and trigger
management opportunities with the aim of reaching high technological, nutritional and
productivity quality and safety of the production.
Keywords
: Fusarium Head Blight, deoxynivalenol,
F. graminearum
epidemiology,
FHB economic impact, crop management systems, predictive models
1.
I
NTRODUCTION
Fusarium Head Blight (FHB), also known as scab, is a devastating disease of enormous
economic importance throughout the world that attacks all classes of barley and wheat. Every
year, all of the most important cereal producers in the world are affected by this disease. As a
consequence, FHB is responsible for serious direct and indirect economic losses.
FHB is caused by different species of the genus
Fusarium
, but two of them represent the
most important species worldwide:
Fusarium graminearum
Schwabe (teleomorph
Gibberella
zeae
(Schw.) Petch.) and
Fusarium culmorum
(W.G. Sm.) Sacc. (teleomorph unknown).
Their temperature requirements determine their relative competitive strength and their
consequent geographical predominance:
F. culmorum
tends to predominate in the cooler
maritime regions of northwest Europe, where
Fusarium poae
(Peck) Wollenw.,
Fusarium
avenaceum
(Corda) Sacc.
and
Microdochium nivale
(Fr.) Samuels & Hallet (syn.
Fusarium
nivale
)
also
assume a greater importance (Birzele et al., 2002; Kosiak et al., 2003; Ioos et al.,
2004). Other less frequently isolated species are
F. poae
,
F. cerealis
(syn. F. crookwellense),
F. equiseti
(syn.
F. scirpi
) (
G. intricans
),
F. sporotrichioides
, and
F. tricinctum
. Many other
species may be sporadically encountered, including
F. acuminatum
,
F. subglutinans
(syn.
F.
sacchari
),
F. solani
, F
. oxysporum
,
F. semitectum
(syn.
F. pallidoroseum
,
F. incarnatum
),
F.
verticillioides
(syn.: F
. moniliforme
), and
F. proliferatum
(Bottalico and Perrone, 2002).
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