Submitted to: Mycotoxin Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2009
Publication Date: 11/20/2009
Citation: Dowd, P.F., Johnson, E.T. 2009. Field incidence of mycotoxins in commercial popcorn and petential environmental influences. Mycotoxin Research. 26(1):15-22. Interpretive Summary: Insects are known to cause physical damage to corn and also increase mold toxin levels in corn, but there is little information on what environmental factors affect levels of these mold toxins in popcorn. A four-year study at multiple locations using commercial popcorn hybrids determined that weather, insect damage, and prior crop can influence the levels of two different mold toxins. This information provides direction for developing management plans and predictive models for mold toxin occurrence in popcorn, which should ultimately lead to lower levels of mold toxins in popcorn. Reduction of mold toxins in popcorn should lead to an economic benefits for producers, marketers, and consumers; a healthier product for consumers and export advantages for U.S.-produced popcorn.
Technical Abstract: Insect ear damage and mycotoxin levels were monitored in several commercial popcorn fields in Central Illinois over a four-year period. Aflatoxin was rare, but fumonisin and deoxynivalenol (DON) were commonly encountered each year and occurred at mean levels in fields up to 1.7 ppm (sample max 2.77 ppm) and 1.9 ppm (sample max 2.66 ppm), respectively. Neither fumonisin nor DON levels were significantly correlated with the percent of ears with visibly moldy insect damaged kernels (few were seen). Significant correlations were noted for the percent of ears with early caterpillar damage (as indicated by discolored pericarps) and both fumonisin and DON levels overall for some years and at specific sites in other years. Fumonisin levels were generally more highly correlated with insect damage than DON levels. Insect damaged kernels had 100-500 fold or greater levels of fumonisin compared to non-insect damaged kernels, while DON levels were closer to 10-30 times higher in insect damaged vs. non-damaged kernels. A high percentage of DON contaminated kernels were not insect damaged in 2007 and 2008. In some cases, differing mycotoxin levels for the same hybrid and same year planted at different locations appeared due to the prior crop. Higher DON levels in 2008 than other years were most likely associated with higher levels of rainfall and cooler temperatures than average during ear fill.