Contamination of sesame seed grown in Mississippi with aflatoxin, fumonisin, and mycotoxin-producing fungi

Abstract

Four sesame varieties (S-34, S-35, S-38, and S-39) were planted in the Mississippi Delta in 2014 and 2015 at four nitrogen fertiliser application rates from 44.8 to 112 kg N/ha, and evaluated for grain yield and contamination by mycotoxins and toxigenic fungi. Variety S-35 had the highest yield in both years. Harvest seed moisture was not related to variety, because opposite results were obtained in the two years. N fertiliser application rate had no effect on yield or mycotoxin contamination of harvested seed in 2014, but significantly increased yield in 2015. Harvested sesame seed density was influenced by treatments (N rates and variety) with varietal differences occurring in the different years. While observed differences were small, even small differences could impact marketability. There was no significant effect of N fertiliser application rate, variety, crop year or interaction between them for contamination of harvested seed by aflatoxins, fumonisins, Aspergillus flavus or Fusarium verticillioides in cleaned and uncleaned harvested sesame seed. Similar results were obtained from trials conducted in the Florida Panhandle during 2015. In general, sesame seed is not susceptible to aflatoxin and fumonisin contamination. None of the mycotoxin levels observed in this study were significant in regard to human or animal health, but further testing is needed. This is the first report of fumonisin found in sesame seed. The results of this study indicate that sesame seed is a safe crop for growers and consumers.