BACKGROUND The aim was to determine the influence of harvesting time and meteorological conditions on the occurrence of Fusarium spp. and mycotoxins in the grain of spring cereals. A field experiment was performed in 2016–2018 with spring oat (Avena sativa L.) and spring triticale (× Triticosecale Wittm.) plots. Grain samples of oat and triticale were analysed for Fusarium infection and co‐contamination with mycotoxins deoxynivalenol (DON), zearalenone (ZEA) and T‐2 toxin (T‐2). RESULTS Results from the three‐year study showed that the occurrence of Fusarium spp. fungi and mycotoxins produced by them in spring oat and triticale grain was most influenced by the meteorological conditions at harvesting time and crop species. CONCLUSIONS It was found that in all experimental years, F. poae, F. tricinctum and F. sporotrichioides predominated in oat grains and F. graminearum, F. sporotrichioides and F. avenaceum predominated in spring triticale; as a result, oat grains were more contaminated with T‐2 and triticale grains with DON and ZEA. Due to the rainy harvesting period in 2017, the contamination level of Fusarium fungi of grain of both crop species was 100%, and the concentrations of DON and ZEA in the samples of spring triticale were several times higher than those set forth in the EU regulation. Co‐occurrence of all three mycotoxins analysed (DON, ZEA and T‐2) was identified in these samples. © 2020 Society of Chemical Industry

Two buckwheat groats processing methods were used for production of final commercial product. The first one involved thermal processing (steamed) and then dehulling, and the second one dehulling without thermal treatment (raw). The research evidenced that the raw groats and hulls were several times more contaminated with aflatoxin B1 compared with steamed ones. High concentrations of aflatoxin B1 (75.8 µg kg −1) and T-2 toxin (351.0 µg kg −1) were detected in the raw hull samples. The total phenolics responded more sensitively to thermal treatment than phenolic acids. More than 20 times higher concentrations of quercetin (65.47 ± 6.3 µg g-1) were determined in steamed hulls compared to other raw and steamed samples. Buckwheat groats and hulls, containing the highest concentrations of quercetin and hydroxybenzoic acids, were found to be 10-fold less contaminated with aflatoxin B1 and T-2 toxins; however, the correlations between the phenolics and mycotoxins were statistically insignificant. El efecto del procesamiento de granos de trigo sarraceno en el contenido de micotoxinas y compuestos fenólicos RESUMEN Se utilizaron dos métodos de procesamiento de granos de trigo sarraceno para la producción del producto comercial final. El primer método incluía procesamiento térmico (vapor) y después descascarillado. El segundo método, se trataba de descascarillado sin tratamiento térmico (crudo). Esta investigación evidenció que los granos crudos y las cáscaras estaban contaminados de aflatoxina B1 en mayor medida que aquellos al vapor. Se detectaron altas concentraciones de aflatoxina B1 (75,8 µg kg −1) y T2 toxina (351,0 µg kg −1 .) en las muestras de cáscaras crudas. El total de fenoles respondió de manera más sensible al tratamiento térmico que los ácidos fenólicos. Se determinaron concentraciones de quercetina (65,47±6,3 µg g −1) 20 veces más en las cáscaras al vapor en comparación con otras muestras crudas y al vapor. Se encontró que los granos de trigo sarraceno y las cáscaras que contenían concentraciones mayores de quercetina y ácidos hidroxibenzoicos, resultaron 10 veces menos contaminadas de aflatoxina B1 y toxinas T2; sin embargo, las correlaciones entre los fenoles y las micotoxinas fueron estadísticamente insignificantes.

Fusarium head blight (FHB) is one of the most serious diseases of small-grain cereals worldwide, resulting in yield reduction and an accumulation of the mycotoxin deoxynivalenol (DON) in grain. Weather conditions are known to have a significant effect on the ability of fusaria to infect cereals and produce toxins. In the past 10 years, severe outbreaks of FHB, and grain DON contamination exceeding the EU health safety limits, have occurred in countries in the Baltic Sea region. In this study, extensive data from field trials in Sweden, Poland and Lithuania were analysed to identify the most crucial weather variables for the ability of Fusarium to produce DON. Models were developed for the prediction of DON contamination levels in harvested grain exceeding 200 µg kg−1 for oats, spring barley and spring wheat in Sweden and winter wheat in Poland, and 1250 µg kg−1 for spring wheat in Lithuania. These models were able to predict high DON levels with an accuracy of 70–81%. Relative humidity (RH) and precipitation (PREC) were identified as the weather factors with the greatest influence on DON accumulation in grain, with high RH and PREC around flowering and later in grain development and ripening correlated with high DON levels. High temperatures during grain development and senescence reduced the risk of DON accumulation. The performance of the models, based only on weather variables, was relatively accurate. In future studies, it might be of interest to determine whether inclusion of variables such as pre-crop, agronomic factors and crop resistance to FHB could further improve the performance of the models.

In this work, we studied the impact of harvesting time on Fusarium mycotoxin occurrence in spring wheat and the effect of mycotoxin contamination on the quality of these grains. The spring wheat grains (Triticum aestivum L.) were collected in 2016–2018 when the crop had reached full maturity, 10 ± 2 days and 17 ± 3 days after full maturity. The grain samples were analyzed for Fusarium infection and co-contamination with mycotoxins deoxynivalenol (DON), zearalenone (ZEA), and T-2 toxin (T-2), as well as the quality of the wheat grains (mass per hectolitre, contents of protein, starch, ash and fat, particle size index (PSI), falling number, sedimentation, wet gluten content, and gluten index). The occurrence of Fusarium spp. fungi and the mycotoxins produced by them in the grains was mostly influenced by the harvesting time and meteorological conditions. The correlations between Fusarium species and the mycotoxins produced by them in the grains of spring wheat showed F. graminearum to be a dominant species, and as a result, higher concentrations of DON and ZEA were determined. The co-occurrence of all the three mycotoxins analyzed (deoxynivalenol, zearalenone, and T-2 toxin) was identified in wheat. In rainy years, a delay in harvesting resulted in diminished grain quality of spring wheat, as indicated by grain mass per hectolitre and falling number. Negative correlations were found in highly contaminated grains between mycotoxins (DON, ZEA, and T-2) and falling number and grain mass per hectolitre values.

Fusarium Head Blight (FHB) is one of the most common worldwide wheat and other small grain diseases. The infection is caused by Fusarium graminearum and other related species, which significantly reduce grain yield and contaminate grains with mycotoxins which are harmful for humans and animals. Fusarium pathogen survives the winter well in plant debris left on the field. Weeds around and within crops are alternative hosts of Fusarium fungi when an economically important host plant is not present. This article focuses on the determination of DNA content of Fusarium species (F. graminearum and F. avenaceum) in artificially inoculated wheat plants with isolates from weeds, as well as its influence on the severity of FHB and spring wheat 1000-grain weight under field conditions. Fungal DNA content in grains was evaluated by quantitative real-time PCR. The results showed that the DNA concentration of F. graminearum was significantly higher in the grain than F. avenaceum. The severity of FHB when wheat heads were inoculated with F. graminearum was significantly higher than with F. avenaceum. All F. graminearum strains statistically significantly reduced the weight of spring wheat grains, while F. avenaceum did not affect the weight of 1000 grain. This investigation has shown that weeds in crop rotations are a potential source of FHB infection. However, the severity of the disease is more affected by the Fusarium species than the host plant. This experiment is, to our knowledge, the first report on the estimation of Fusarium DNA content in artificially inoculated wheat plants with isolates from weeds, as well as its comparison with pathogenicity to wheat and its effect on 1000-grain weight.