© Benaki Phytopathological Institute
Hellenic Plant Protection Journal - Special Issue
88
Succinate dehydrogenase inhibitors (SDHIs)
constitute a fungicide class of increasing rel-
evance in crop protection. These fungicides
could play a crucial role in the successful
management of grey mould disease. In the
current study the effect of fluopyram, a nov-
el SDHI fungicide, on several developmental
stages of
Botrytis cinerea
was determined
in
vitro
, and its protective and curative activi-
ty against the pathogen was determined in
strawberry fruit. Furthermore, fungal base-
line sensitivity was determined in a set of
192 pathogen isolates. Germ tube elon-
gation was found to be the most sensitive
growth stage affected by fluopyram, while
mycelial growth was found to be the least
sensitive growth stage. Fluopyram provid-
ed excellent protective activity against
B.
cinerea
when applied at 100 μg ml
-1
96, 48
or 24h before the artificial inoculation of
the strawberry fruit. Similarly, fluopyram
showed a high curative activity when it was
applied at 100 μg ml
-1
24h post-inocula-
tion, but when application was made 48 or
96h post-inoculation disease control effica-
cy was modest or low. The measurement of
baseline sensitivity showed it to be unimod-
al in all populations tested. The individual
EC
50
values for fluopyram ranged from 0.03
to 0.29 μg ml
-1
. In addition, no correlation
was found between sensitivity to fluopy-
ram and sensitivity to other fungicides in-
cluding cyprodinil, fenhexamid, fludioxonil,
iprodione, boscalid and pyraclostrobin. The
obtained biological activity, baseline sen-
sitivity and cross-resistance relationships
data suggest that fluopyram could play a
key-role in grey mould management in the
near future and encourage its introduction
into spraying programmes.
Sensitivity of isolates of the fungi
Aspergillus niger
and
Aspergillus
carbonarius
in registered fungicides in viticulture
M. B
ERTOLI
, M. D
IMAKOPOULOU
and D.I. T
SITSIGIANNIS
Agricultural University of Athens, Department of Crop Science, Laboratory of Plant
Pathology, Athens, Greece
The filamentous fungi
Aspergillus niger
and
A. carbonarius
cause significant rot prob-
lems in grapes at pre-harvest and post-har-
vest level and produce various carcinogenic
mycotoxins (i.e. ochratoxin A) in grape ber-
ries and wine. The goal of this study was to
evaluate 14
A. niger
and
A. carbonarius
iso-
lates from the fungal collection of the Labo-
ratory of Plant Pathology in Agricultural Uni-
versity of Athens (isolated from grapes in
different regions of Greece) for sensitivity in
various fungicides that are included in viti-
culture plant protection programs. The first
experiments were performed with the ac-
tive ingredients fludioxonil, cyprodinil and
azoxystrobin used alone and/or in combi-
nation with salicylhydroxamic acid (SHAM-
inhibitor of alternative cellular respiration).
The applied concentrations of the active in-
gredients fludioxonil and cyprodinil were
0.01, 0.05, 0.1 and 0.5 ppm for azoxystrob-
in 0.01, 0.1, 1.0 and 10.0 ppm and 100.0 ppm
for SHAM. First, cyprodinil showed higher
inhibition rates in all of the tested isolates
compared to fludioxonil at all concentra-
tion rates. After six days of incubation of the
plates with the fungal isolates, the two fun-
gicides showed a statistical difference be-
tween themonly in the two lower concentra-
tions. The tested
A. niger
and
A. carbonarius
isolates did not demonstrate any statistical-
ly significant difference between them re-
garding their sensitivity to the two active
ingredients of fludioxonil and cyprodinil.
In azoxystrobin, all isolates showed moder-
ate sensitivity which was increased signifi-
cantly when SHAM was added in the medi-
um. The exception was the isolation 315 (an
A. carbonarius
strain isolated from the grape
variety Corinthiaki Stafida from Trikala in
Corinthia) that showed a small inhibition in
all four treatments of fludioxonil, cyprodinil,
azoxystrobin and azoxystrobin+SHAM. This
particular isolate has preserved this resis-
