Natural occurrence of mycotoxins in forage maize during crop growth in Japan: case study

Abstract

We investigated concentrations of mycotoxins during the growth of four cultivars of forage maize (Zea mays L.) in Nasushiobara, Tochigi prefecture, and their distribution in ears of maize grown in Morioka, Iwate prefecture, Japan. In experiment 1, we measured concentrations of naturally occurring fumonisin, nivalenol, deoxynivalenol and zearalenone at progressive crop growth stages. Concentrations of fumonisin in stems+leaves remained very low or not detectable, but those in ears became detectable at 40 days after heading and increased rapidly after 50 days after heading (DAH) (fumonisin B1+B2<3260 μg/kg; mean value at 50-74 days after heading). Concentrations varied widely within cultivars on the same day. Concentrations of nivalenol, deoxynivalenol and zearalenone in stems+leaves and in ears were low or not detectable throughout the experiment. In experiment 2, we collected three ears of each cultivar at the late yellow-ripe stage that showed extreme symptoms of Fusarium ear rot. Concentrations of fumonisin were extremely high in the upper half of ears in all cultivars (fumonisin B1+B2 18,000-25,900 μg/kg) but low in the lower half and bracts. Concentrations of nivalenol, deoxynivalenol and zearalenone were extremely low or not detectable. These results show that fumonisin concentrations in ears increased rapidly after 50 DAH, they were extremely high in ears of all cultivars with symptoms of Fusarium ear rot, and fumonisin was the most common contaminant. These results will help reduce mycotoxin contamination.

Fumonisin reduction using fungicides in forage corn cultivation

“…In the case of the Kimimaru corn in 2016, the FM concentration was higher in the fully ripe stage than in the yellow ripening stage (Figure 2). This result is similar to that obtained in 2015 and a previous report (Uegaki et al, 2015). In contrast, in LG3490, the concentration of FM during the yellow ripening period (control: 10.5 mg/kg) was already as high as that during the fully ripe stage (control: 10.8 mg/kg) (Figure 2), and neither fungicide was effective in reducing the FM concentration.…”

“…The concentrations differed between the types, but both values doubled. This is the same tendency as previously reported (Uegaki et al, 2015). This result may be caused by the proliferation of FM‐producing fungi as the corn ripens, increasing FM production.…”

Variations in the yield and moisture content of ears of forage corn varieties with different relative maturity

“…Asian corn borer feeding on the ear also promotes fungal infection and mycotoxin synthesis (Maiorano et al, 2009). The mycotoxin accumulation increases rapidly in the corn ear after the yellow ripe stage (Okabe, 2015;Uegaki et al, 2015) and is addictive to farm animals and regulated by concentration value in formula feed (FAMIC, 2021). Climate risk can be posed by typhoons, which cause yield decline because of crop lodging by strong wind or heavy rain (Kanno et al, 2021;Minami & Ujihara, 1991).…”

Development of an analytical method for fumonisin B₁ in porcine tissues and body fluids using UHPLC-MS/MS

“…Fumonisin B 1 (FB 1 ) is one of the major mycotoxins produced by Fusarium fungi and mainly contaminates corn and corn-derived products (WHO, 2000). In Japan, FB 1 -producing fungi and FB 1 have been widely detected in forage grains and animal feeds (Uegaki et al, 2015(Uegaki et al, , 2018. Among the various fumonisins identified, FB 1 is the most harmful to animals (EFSA, 2018) and it exhibits highly species-specific toxicities.…”