Fusarium mycotoxins in UK oats. Simon Edwards

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1 Fusarium mycotoxins in UK oats Simon Edwards

2 Presentation Fusarium head blight on oats Legislation for oats HT2 + T2 in UK oats Impact of agronomy Impact of processing

3 Fusarium Head Blight in Oats Less of an issue than FHB on wheat and barley. Fusarium graminearum issue in N. America and recently in Nordic countries. Results in mycotoxins, deoxynivalenol and zearalenone, in harvested grain. Fusarium langsethiae common FHB pathogen in UK oats F. langsethiae predominant HT2+T2 producer in oats F. langsethiae do not produce symptoms on growing crop or harvested grain Unable to inoculate F. langsethiae successfully in field

4 EU Mycotoxin Legislation Maximum legal limits for unprocessed oats intended for human consumption (July 2006) Mycotoxin Deoxynivalenol 1750 Zearalenone 100 HT2+T2 Legal limit (ppb) 1000 (indicative level) Lower limits for retail products and infant food European Commission published indicative levels for HT2+T2 in HT2+T2 to be monitored and investigations instigated where indicative levels are exceeded. Control options to be reviewed in 2015 (2016?).

5 Fusarium mycotoxins in UK oats DON Number Incidence, % Mean Median <10 <10 <10 <10 <10 <10 <10 >1750ppb, % ZEARALENONE Number Incidence, % Mean Median <5 <5 <5 <5 <5 <5 <5 >100ppb, % HT2+T Number Incidence, % Mean Median >1000ppb, %

6 Occurrence data since 2008 Monitored as part of AHDB contaminants projects at Campden BRI but limited to low sample numbers (ca. 10). High mean (529 ppb) in 2009, since then mean has been ca. 100 ppb and few samples have exceeded 1000 ppb. Commercial mill intake samples in agreement with this until 2014 harvest.

7 Impact of agronomy Various UK oat studies since Observational surveys of commercial crops - Field experiments of single agronomic factors Organic and conventional UK oats Previous crop and cultivation N rates x PGR Fungicides Variety

8 HT2 and T2 (ppb) DON (ppb) Observational study Conventional and organic oats HT2 and T2 in oats DON in Wheat Conventional Organic 0 Conventional Organic Practice Practice

9 HT2+T2 (ppb) Observational study Cereal intensity within rotation Intensity = number of previous cereal crops based on last four year data >3 Cereal intensity 9

10 Industry funded agronomy trials Conducted over 3 years for winter and spring sown varieties (n=6) Variety x Nitrogen rate x PGR Winter oat varieties: Gerald, Mascani and Brochan Nitrogen rates: 96, 108 and 120 kg/ha N PGR: +/- 1.7 l/ha 3C chlormequat applied at GS31-32 Spring oat varieties: Firth, Leven, Husky Nitrogen rates: 96, 108 and 120 kg/ha N PGR: +/- 1.7 l/ha 3C chlormequat applied at GS31-32

11 Industry funded agronomy trials Conducted over 3 years for winter and spring sown varieties (n=6) Variety x Nitrogen rate x PGR Variety had a significant effect Nitrogen rates had no significant effect PGR use had no significant effect

12 HT2+T2 (ppb) QUOATS Project Nitrogen trials Conventional (ADAS) and Organic (ORC) trials with variable N rates. Conventional with Nil rate and RB209 rate 30% lower HT2+T2 with RB209 rate Organic with Nil rate and additional 60 kg N (poultry manure) no difference Nil RB209

13 Industry funded agronomy trials Conducted over 3 years for winter (Gerald) and spring sown (Firth) varieties (n=6) Treatment Growth Stage GS GS 39 GS Untreated Untreated Untreated 2 Opus 0.4 l Opus 0.4 l Untreated Flexity 0.2 l Amistar 0.75 l 3 Opus 0.4 l Fandango 0.8 l Untreated Flexity 0.2 l 4 Opus 0.4 l Untreated Opus 0.4 l Flexity 0.2 l Amistar 0.75 l 5 Opus 0.4 l Untreated Fandango 0.8 l Flexity 0.2 l 6 Opus 0.4 l Opus 0.4 l Fandango 0.8 l Flexity 0.2 l Amistar 0.75 l 7 Opus 0.4 l Fandango 0.8 l Opus 0.4 l Flexity 0.2 l Amistar 0.75 l 8 Opus 0.4 l Fandango 0.8 l Opus 0.4 l Flexity 0.2 l Amistar 0.75 l 9 Opus 0.4 l Untreated Opus 0.4 l Flexity 0.2 l Folicur 0.4 l 10 Opus 0.4 l Opus 0.4 l Untreated Flexity 0.2 l Folicur 0.4 l 11 Opus 0.4 l Untreated Proline 0.3 l Flexity 0.2 l Comet 0.3 l 12 Opus 0.4 l Opus 0.75 l Untreated Flexity 0.2 l Folicur 0.75 l 13 Opus 0.4 l Untreated Opus 0.75 l Flexity 0.2 l Folicur 0.75 l 14 Opus 0.4 l Opus 0.75 l Opus 0.75 l Flexity 0.2 l Folicur 0.75 l Folicur 0.75 l Amistar; 250 g/l azoxystrobin Fandango; 100 g/l fluoxastrobin g/l prothioconazole Flexity; Folicur; Opus; Proline; 300 g/l metrafenone, 250 g/l tebuconazole 125 g/l epoxiconazole 250 g/l prothioconazole

14 Industry funded agronomy trials Conducted over 3 years for winter and spring sown varieties (n=6) Fungicides Fungicide input had no significant effect

15 HT2+T2 (ppb) Oat varietal resistance AHDB RL data Winter Oats Spring Oats After name (N, naked; S, short-strawed).

16 Oat varietal resistance PhD investigating varietal resistance See Tijana Stancic (Poster 11) Is difference between spring and winter varieties genetic or agronomic (ie sowing date)? Is height a morphological resistance trait? Is nakedness a morphological resistance trait?

17 Agronomy Summary High levels can occur on UK oats Previous crop and cultivation differences not consistent Nitrogen rates within normal range have no significant effect PGR inputs have no significant effect Fungicide applications have no significant effect Lower levels on organic oats Lower levels in less intense cereal rotations Lower levels on UK spring oat varieties

18 Good agricultural practice? Not economically feasible to grow oats in a rotation without other cereals Not economically feasible to switch from Winter to Spring varieties due to yield penalty Need to identify/develop high yielding/high quality winter varieties with resistance to Fusarium / low accumulation of HT2+T2

19 Impact of Processing Majority of trichothecenes in outer hull (husk) All oats are de-hulled for human consumption Lower concentration in retail oat products Mycotoxin concentration high in the pelleted by-product used for animal feed, typically 3-fold higher

20 Summary DON (and ZON) currently not an issue in UK oats EC legislation for HT2 and T2 to be reviewed in 2016? Current indicative limit for unprocessed oats is 1000 ppb HT2+T2 High levels of HT2 and T2 in UK in some years Limited reduction available by Good Agricultural Practice Good reduction by de-hulling (Good Manufacturing Practice) High levels in oat pellets used in animal feed

21 Acknowledgements UK funding bodies for financial support: - Danielle Henderson (Harper Adams University) - Sandy Cowan and Catherine Howarth (University of Aberystwyth, UK) - Richard Jennaway (Saaten Union, UK) - Ingerd Skow Hofgaard (Bioforsk, Norway)