HT-2 and T-2 toxins in Norwegian oat grains related to weather conditions at different growth stages

Abstract

High concentrations of the mycotoxins HT-2 and T-2 (HT2 + T2), primarily produced by Fusarium langsethiae, have occasionally been detected in Norwegian oat grains. In this study, we identified weather variables influencing accumulation of HT2 + T2 in Norwegian oat grains. Oat grain samples from farmers' fields were collected together with weather data (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013). Spearman rank correlation coefficients were calculated between the HT2 + T2 contamination in oats at harvest and a range of weather summarisations within estimated phenological windows of growth stages in oats (tillering, flowering etc.). Furthermore, we developed a mathematical model to predict the risk of HT2 + T2 in oat grains. Our data show that adequate predictions of the risk of HT2 + T2 in oat grains at harvest can be achieved, based upon weather data observed during the growing season. Humid and cool conditions, in addition to moderate temperatures during booting, were associated with increased HT2 + T2 accumulation in harvested oat grains, whereas warm and humid weather during stem elongation and inflorescence emergence, or cool weather and absence of rain during booting reduced the risk of HT2 + T2 accumulation. Warm and humid weather immediately after flowering increased the risk, while moderate to warm temperatures and absence of rain during dough development, reduced the risk of HT2 + T2 accumulation in oat grains. Our data indicated that HT2 + T2 contamination in oats is influenced by weather conditions both pre-and post-flowering. These findings are in contrast with a previous study examining the risk of deoxynivalenol contamination in oat reporting that toxin accumulation was mostly influenced by weather conditions from flowering onwards.

Genome‐wide association mapping of Fusarium langsethiae infection and mycotoxin accumulation in oat (Avena sativa L.)

“…In this study, high rainfall and low temperatures around anthesis favoured the growth of F.langsethiae (Supplemental Figure S4) and increased T-2 and HT-2 contamination. This is in agreement with recent studies (Hjelkrem et al, 2018;Kaukoranta et al, 2019;Schöneberg et al, 2019) that associated cold temperatures before anthesis and warm temperatures during the 3-weeks after anthesis with increased grain infection and toxin levels. The 2018 environment was hotter and drier during anthesis, which resulted in lower grain infection (Supplemental Figure S4).…”

Contrasting responses of T-2, HT-2 and DON mycotoxins and Fusarium species in oat to climate, weather, tillage and cereal intensity

“…A comparison of the weather responses observed in Finland, the UK (Xu et al 2014) and Norway (Hjelkrem et al 2018) shows that the responses are qualitatively remarkably similar with only minor differences. Early in the season, temperature response was weaker in Finland than in the UK, but due to late sowing in Finland this period is warmer and drier in Finland than in the UK Table 3 For predictions shown in Figs.…”

Agronomic Factors Influencing the Scale of <em>Fusarium</em> Mycotoxin Contamination of Oats

“…In this study, 15 samples (7.4%) were found to contain levels of combined T-2 and HT-2 above the EU recommended limits (Table 5). Previous mycotoxins surveys have also shown that oats produced particularly in Northern and Western Europe are more susceptible to T-2 and HT-2 contamination compared to other cereals -wheat, barley and Rye [15,[36][37][38]. A very high prevalence of T-2 and HT-2 toxins was observed in 458 unprocessed oat samples collected between 2002 and 2005 from various oat fields in the UK [36].…”