Effects of Fusarium infection of wheat on mycotoxin concentration in straw when stored under different conditions

Publication Type

Contribution to conference

Authors

Rohweder D., Valenta H., Sondermann S., Schollenberger M., Drochner W. and Dänicke S.

Year of publication

2008

Published in

Conference Abstracts

Editor

Gesellschaft für Mykotoxinforschung e.V.

Series/labeling

Mycotoxin-Workshop

Page (from - to)

127

Conference location

Utrecht (Niederlande)

Conference date

28.04.2008

Keywords

Fusarium culmorum, mycotoxins, Stroh

Introduction: Fusarium head blight is an important plant disease in cereals. As consequence thereof not only the grains might be contaminated with mycotoxins but also the remaining parts of the plant, i.e. straw and chaff. Cereals straw is mostly used as bedding material, but also as a structural component in ruminant feeding. Straw is sometimes stored under unfavourable conditions which enable a post-harvest water uptake which favours initiation and progression of microbiological destruction and mycotoxin formation.The aim of the present experiment was to investigate the time course of the concentration of mycotoxins of Fusarium infected and not infected straw under different storage conditions.

Materials and Methods: The wheat straw (Straw from Fusarium culmorum inoculated [F] and not inoculated wheat [C]) was stored either in a barn (B) or outdoor (0) covered by a tarp. Samples of the four variants of straw (CB, FB, CO and FO) were taken at the beginning of the storage period and after 2, 4, 8 and 16 weeks. The samples were dried, ground to pass a 1 mm screen and frozen at -18°C until analyses. Zearalenone (ZON) was determined by HPLC with fluorescence detection according to a preliminarily method of the VDLUFA with slight modifications.

Results: The initial ZON concentrations of the C- and F-straw were 100µg/kg DM (dry matter) and 604µg/kg DM, respectively. The ZON concentration of the CB-straw remained at the initial level after storage time of 16 weeks whereas a small increase was found for the FB-straw. In the outdoor storage variants the ZON contents increased in the CO-straw by approximately 800µg/kg DM and in the FO-straw by approximately 1400µg/kg during the 16 weeks of storage. The dry matter of the straw stored outdoor decreased down to approximately 50 %, whereas the dry matter of the straw stored in the barn remained at the initial dry matter of approximately 84 %.

Discussion and Conclusion: Outdoor storage of straw favoured the post-harvest water uptake by straw and induced an increase in the ZON concentration when compared to the straw stored inside the barn. The degree of this increase depended on the initial ZON concentration and was more pronounced In the F-straw.