Survey of the occurrence of deoxynivalenol (vomitoxin) in barley grown in MN, ND and SD during 1993.

Schwarz, P.B., Casper, H.H. and Barr, J.M.

Abstract
The upper midwestern barley growing region of the USA, comprising the state of North Dakota plus adjacent parts of two neighbouring states (western Minnesota and northeastern South Dakota), was afflicted by widespread Fusarium infection during the 1993 barley growing season. Because of concern over possible mycotoxin contamination, 204 barley samples from the region were analysed for deoxynivalenol (DON). Results ranged from negative (i.e. below the detection limit of 0.2 micrograms/g) up to 22 micrograms/g. The highest DON levels were found in the eastern part of the region (Minnesota, South Dakota and eastern North Dakota) where most samples were found to be contaminated, whereas contamination was less common in the central area of North Dakota and extremely rare in the west of that state. No significant amounts of any of 16 other mycotoxins were found in any of the composite samples (made up by blending a portion of grain from each county within a crop reporting district) analysed for them. A significant negative correlation between DON contamination and grain weight per unit of volume was found, but no statistically significant relationships with other quality parameters were identified. However, it was noted that the area where contamination was most severe was largely devoted to six rowed varieties, whereas two rowed barley predominates in the less badly affected parts of the region.
Keywords : barley contamination Fusarium mycotoxin survey