Tests for field mould and associated mycotoxins in South Australian lentil (Lens culinaris) grain

Abstract

Rain events in South Australia during the lentil harvest of 2010/2011 raised concerns as to whether grain had been infected with field moulds and associated mycotoxins. Grain samples from commercial crops were tested for the mycotoxins Deoxynivalenol (DON = Vomitoxin), Fumonisin B1 and B2 and zearalenone, which are produced by Fusarium spp. Sampling was biased towards more severely affected grain to increase the probability of detection of moulds and toxins, including worst case samples of discarded waste grain (screenings) from cleaning plants. No mycotoxins were detected although Fusarium spp. were detected in all but three of the samples. No Alternaria or Aspergillus spp. were detected. Fusarium spp. were detected at a higher level in grain harvested after a significant rain event in December 2010 compared to grain harvested prior to this event. Percentage of stained seed was higher in plants sampled in machinery wheel tracks compared to those from the remainder of the paddock. The fungal pathogen Ascochyta lentis was also detected on the grain but percentage infection was not affected by harvest date. No Botrytis spp. were detected on the samples. The pilot study identified that the lentil grain in these samples from the 2010/2011 harvest in South Australia was free of mycotoxins and posed no risk to humans or livestock. © 2012 Australasian Plant Pathology Society Inc.