EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 5: DISEASE CONTROL AND FORECASTING MODELS<br />
Wheat monitoring in Switzerland: Which cropping<br />
factors influence occurrence <strong>of</strong> Fusarium species and<br />
mycotoxins?<br />
S. Vogelgsang, I. Bänziger, T. D. Bucheli, F. E. Wettstein, H. R. Forrer<br />
Agroscope Reckenholz-Tänikon Research Station ART, 8046 Zurich, Switzerland<br />
E-mail: susanne.vogelgsang@art.admin.ch<br />
Throughout four years, wheat samples and information on cropping measures<br />
were collected from Swiss growers. Wheat grains were examined for incidence <strong>of</strong><br />
various Fusarium head blight (FHB) causing species, DNA amount <strong>of</strong> F.<br />
graminearum (FG) and content <strong>of</strong> different mycotoxins. In a total <strong>of</strong> 527 samples<br />
from 16 cantons, three Fusarium species were dominant: FG (64%), followed by<br />
F. poae (19%) and F. avenaceum (10%). The mean content <strong>of</strong> deoxynivalenol<br />
(DON) was 650 ppb and 12% <strong>of</strong> all samples were above the European limit for<br />
unprocessed cereals (1’250 ppb). The mean DON content varied between 260<br />
ppb in 2009 and 970 ppb in 2008. There was a significant positive correlation<br />
between FG incidence and DON content (r 2 =0.52) and between FG DNA quantity<br />
and DON content (r 2 =0.64).<br />
The combination <strong>of</strong> pre-crop maize and conservation tillage versus ploughing<br />
resulted in an average DON content <strong>of</strong> 2’200 ppb or 370 ppb, respectively. The<br />
use <strong>of</strong> other pre-crops further reduced the average DON content to 240 ppb. In<br />
samples from the two cropping systems wheat after maize with or without<br />
ploughing, zearalenone and nivalenol (NIV) contents were lower but showed a<br />
similar pattern as that DON, with means <strong>of</strong> 208 and 17 ppb for ZEA and to 27<br />
and 16 ppb for NIV, respectively. No significant correlation was found between F.<br />
poae incidence and the NIV content. One reason may be the presence <strong>of</strong> F.<br />
graminearum NIV chemotypes in Switzerland.<br />
Currently, DNA quantities <strong>of</strong> F. poae as well as the ratio <strong>of</strong> FG chemotypes are<br />
investigated by PCR analyses. The resulting data combined with in-depth<br />
multivariate analysis <strong>of</strong> various cropping measures will provide a better<br />
understanding <strong>of</strong> the relationship between fungal prevalence and toxin content.<br />
This knowledge is crucial to develop sustainable cropping systems with low risks<br />
<strong>of</strong> Fusarium occurrence and contamination <strong>of</strong> wheat.<br />
Keywords: cropping, Fusarium head blight, monitoring, wheat<br />
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