Fusari Um Guide

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Guidelines to minimise risk of

fusarium mycotoxins in cerealsSummer 2007

Home-Grown Cereals Authority Updated

Autumn2007


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Regulations have been introduced settingegal limits for certain mycotoxins incereals and cereal products intended forhuman consumption. In recent years veryfew grain samples from UK crops haveexceeded these limits.

These guidelines aim to help the industrydentify the risk factors and theappropriate agronomy which canminimise risk of mycotoxins from field

nfections. They also aim to identify whentesting is appropriate without incurringneedless costs.

These guidelines should be read inconjunction with the UK Codes of Practiceproduced by the Food Standards Agency,see: www.food.gov.uk/foodindustry/farmingfood/fusariumadvice

Occurrence and significanceMycotoxins are toxic chemicals produced by specificungi which infect crops. Different fungal species

produce mycotoxins of widely varying toxicity tohumans and animals; hence there are differentpermitted levels in foodstuffs and feed.

n cereals, mycotoxins can result from fungi that eitherdevelop in stored crops or from field-borne infections.This publication focuses on the fusarium mycotoxins,which can arise from field-borne infection. Whileusarium mycotoxins remain stable during storage inhe UK, levels do not normally increase.

Mycotoxins from field fungi

Five Fusariumspecies:F. avenaceum, F. culmorum,F. graminearum, F. poaeandF. langsethiae; andMicrodochium nivaleandM.majusinfect cereals and maycause head (ear) blight.However, Microdochiumspecies do not producemycotoxins.

Some FusariumandMicrodochium species alsocause seedling blight andbrown foot rot (see The WheatDisease Encyclopaedia).

Infection of ears by Fusariumspecies can result inmycotoxin development when the weather is warmand wet at flowering. Mycotoxin occurrence may begreater when wet weather delays harvest.

Crops infected at flowering may have individualbleached spikelets, or partially bleached ears, resultingat harvest in pink or chalky-white shrivelled grains.However, there is little correlation between fusarium-damaged grains and mycotoxin occurrence.

Fusarium mycotoxins

)bpp(levelN

O

D

0

200

400

600

800

1000

1200

2001 2002 2003 2004 2005 2006Wheat 200106 Barley 200205 Oats 200205

Maximum permitted level for unprocessed wheat and barley

intended for human consumption (limit for oats is 1,750ppb)

Figure 1. Average DON concentration inex-combine cereal samples harvested2,800 samples)

)bpp(levelenonelaraeZ

0

20

40

60

80

100

120

2001 2002 2003 2004 2005 2006Wheat 200106 Barley 200205 Oats 200205

Maximum permitted level for unprocessed wheat,

barley and oats intended for human consumption

Figure 2. Average zearalenone concentrationin ex-combine cereal samples harvested(2,500 samples)

1 Guidelines to minimise risk of fusarium mycotoxins in cereals

Mycotoxins from storage fungiOnce in storage, grain may be infected by fungi,such as Penicillium verrucosum, which canproduce the mycotoxin ochratoxin A when grain isstored damp, even for short periods. Grain above18% moisture content is at risk.

Legal limits for ochratoxin A are 5ppb (parts perbillion) for grain intended for human consumptionand 3ppb in finished cereal products.

(seeThe grain storage guide).


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Occurrence of mycotoxins in UK cereals

Levels of mycotoxins in cereals were assessed in HGCAand FSA-funded work across the UK.

The most common fusarium mycotoxins of concern aredeoxynivalenol (DON) and zearalenone. There are legalimits for these mycotoxins in grain intended for humanconsumption. HT-2 and T-2 are also found in cereals and legalimits are under consideration.

Average results in wheat, barley and oats for DON andzearalenone are shown in Figures 1 and 2.

Wheat

DON and zearalenone are frequently detected in wheat, butaverage concentrations are well below the legal limits. Lesshan 3% of all samples taken between 2001 and 2006

exceeded the legal limits for DON and zearalenone.

Barley

n general barley had very low levels of DON andzearalenone compared to wheat and legal limits werenot exceeded.

Oats

n general mycotoxin levels were low compared with wheat.The predominant Fusariumspecies that infect oats producehe mycotoxins HT-2 and T-2, for which there are currently noegal limits. However, ongoing research is investigating theisk factors associated with mycotoxins in oats.

There is good evidence that at least 90% of mycotoxins areemoved during de-hulling. In 2003, a FSA survey of fusarium

mycotoxins in retail oat products concluded exposure tohese toxins from this group in the UK diet is very low.

Maize

In the UK crop debris from maize grown for silage or graincan be a significant source of fusarium inoculum forfollowing small grain cereal crops.

Control of fusarium in wheat

Rotation and cultivation help to reduce overwinteringinoculum by lowering levels of infected crop debris on thesoil surface.

Fungicides can provide control at various stages of thediseases life cycle:

1. Seed treatment: the main method of controllingseedling blight (see Wheat seed health and seed-borne diseases a guide).

2. T1 fungicides: control stem-base disease, but notappropriate if only fusarium is present.

3. Effective T3 fungicides (eg dimoxystrobin, metconazole,tebuconazole or prothioconazole): specifically controlfusarium head blight and other diseases (see Wheatdisease management guide).

HGCA-funded R&D has indicated that:

using azoles at half to full rate significantly reducedDON concentration in harvested grain.

more reliable fusarium head blight control may beachieved by angling nozzles backwards. Medium sprayquality, or air-included sprays, may provide bettercontrol than fine sprays.

Guidelines to minimise risk of fusarium mycotoxins in cereals 2

Head blightsymptoms

Splashdispersalof conidiaup plant

Seedinfection

Seed infectioncauses dampingoff and earlyinfection of plant

Dark brown

lesions onstem baseand verticalstreaks upstem

Overwinters in crop debris,grass weeds and volunteers,and as chlamydospores on soil

In established crops, spores

are splashed up the plantstem and leaves by rainfallduring flowering and grainformation. This may lead tohead blight and seed-borne

infection.

Crop debris, stubble and

volunteers are moreimportant sources offusarium than seed. Earlyinfections in wet weathercan cause seedling diseases,

eg damping off, which maythreaten establishment ofuntreated seed.

Figure 3. Life cycle ofFusarium species


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PleaseNote:Theinformationinthissection has now been updated.Youcanfindtheupdatedinformationviathefollowinglinkhttp://www.hgca.com/document.aspx?fn=load&media_id=5511&pu

blicationId=2764


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Mycotoxin levels in grain vary from year to year and between regions. The key factorsaffecting likely risk in wheat are: preceding crop, crop residues, variety, agronomy, andweather at flowering and harvest.


The risk factors Importance

Variety

More resistant varieties have a lower risk of fusarium mycotoxin contamination.

Current UK wheat varieties have a limited range of resistance to head blight.

Consider head blight resistance in choice of winter wheat varieties from the HGCARecommended List.

Moderate risk

Wheat varieties withrating 5 and below

Low risk

Wheat varieties withrating 6 and above

Lodging

Lodging causes humid conditions conducive to mycotoxin production.

Consider a PGR application at the appropriate dose and timing.

Moderate risk

Lodged cropsLow risk

Standing crops

Harvest

Other agronomic factors

A range of broad-leaved and grass weeds, as well as some insects, can carry fusarium leading toinfected weed and crop debris as well as a carry-over of spores.

Grain that could becontaminated

must be stored separately fromother cereals intended for humanconsumption.

Test suspect samples forfusarium mycotoxins.

Good storage practice

aims primarily to preventformation of ochratoxin A.

Clean grain, if necessary.

Dry (and cool) grain:

to under 18% moisturecontent within days of

harvest. to under 15% for long-

term storage.

Meeting end-user needs

Using as many components ofGood Agricultural Practice(ie factors presenting a low risk)as possible helps minimisefusarium mycotoxins at harvest.However, requirements ofsustainable cereal production

and of the end-user also need tobe considered.

Consult end-user on grainrequirements.

Assess risk at:1. start of season consider likely effects of rotation and agronomy.

2. early flowering take account of recent and forecast rain in deciding need tospray against fusarium.

3. harvest review all factors to determine mycotoxin risk and potential end-usefor grain.

For traceability purposes, it is always best to perform a risk assessment anddocument the actions to be taken.

The highest concentrations of mycotoxins are found in fusarium-damaged grains and chaff.

Set combine, especially fan speed, to minimise retention of light fusarium-damaged grainsand chaff.

Combine and store weathered or lodged crop areas separately where possible.

Moderate risk

Damaged grain

Delayed harvest


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Pleasenote:theinformationinthissectionhasnowbeenupdated.YoucanfindtheupdatedInformationviathefollowinglink:http://www.hgca.com/

document.aspx?fn=loa

d&media_id=5511&publicationId=2764


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Testing

Testing methodsMethods range from simple on-farm tests indicating thepresence/absence of a specific mycotoxin, to officially-ecognised and validated methods quantifying anyevels present. For all methods prior extraction from aground sample of grain is needed.

Qualitative lateral flow dipstick methodsndicate the presence or absence of a specificmycotoxin above a set threshold. Presence, or absence,of a test band is interpreted by reference to themanufacturers instructions.

Quantitative assay methods measure theconcentration of a specific mycotoxin. Test kits areavailable in two formats:

Quantitative lateral flow, similar to the qualitativemethod, is suitable when a single determination isrequired, eg grain storage/intake (6-8/test).

Micro-titer plate ELISAmeasures the intensity ofcolour produced by chemicalreactions and is suitablefor analysing multiple samples

(7-9/test).

Confirmatory analysisuses sophisticated, costlyinstruments operated by highly-skilled staff. Methods arevalidated according to (EC) No401/2006 and conducted bylaboratories with current UKAccreditation Service (UKAS)status (over 100/test).

Testing records should bekept for at least two years.

Test supplier Charm Sciences Neogen Corporation R-Biopharm Rhone Romer Labs

Qualitative test *Rosa DON P/N *Reveal for DON RIDAQUICK DON N/A

Quantitativetest

Rosa DON Quantitative Veratox5/5 RIDASCREEN Fast DON AgraQuant DON

Contact details www.charm.com

UK agent:

Calibre Control International Ltd

www.calibrecontrol.com

Asher Court

Lyncastle Way

Appleton

Warrington

WA4 4ST

Tel: 01925 860401

[email protected]

www.neogeneurope.com

Cunningham Building

Auchincruive

Ayr

KA6 5HW

Tel: 01292 525 275

[email protected]

www.r-biopharmrhone.com

West of Scotland Science Park

Unit 3.06 Kelvin Campus

Glasgow

G20 0SP

Tel: 0141 945 2924

[email protected]

www.romerlabs.com

UK agent:

Tepnel BioSystems Ltd

www.tepnelbiosystems.com

One Newtech Square

Deeside Industrial Park

Deeside

Flintshire

CH5 2NT

Tel: 01244 280202

[email protected]

* Semi-quantitative

Examples of DON test kits


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Acknowledgements

These guidelines were conceived byDr Simon Hook and Dr Roger Williams,HGCA and are based on projects fundedby HGCA and the Food StandardsAgency, led by Dr Simon Edwards,Harper Adams University College andDr Neal Matthews, Campden andChorleywood Food Research Association.

HGCA is grateful to many people whohave commented on draft versions of theguidelines, including: Bill Clark, ADAS;Liz Kerrigan, AFS; Paul Rooke, AIC;Dr Denise Baxter, BRi; Paul Cliffe,Calibre; Dr Phil Jennings and Dr JudithTurner, CSL; Dr David Cooper and RobinManning, Defra; Dr Matthew Barber,FSA; Jane Johnson, Genesis; FikiriniRamadhani, Harper Adams UniversityCollege; Andrew Cragg, Andrew Flux,Dr Simon Hook, Professor Graham Jellisand Dr Roger Williams, HGCA; Dr PaulNicholson, JIC; Colin West, MAGB;Dr Nigel Davies, Muntons; Dr ClareHazel, RHM; Carol Donnelly, R-BiopharmRhone; Beth Hall, Syngenta; and JimOrson, TAG.

Edited by Dr Clive Edwards, HGCA andGeoff Dodgson, Chamberlain.

Design by Chamberlain

Further information

HGCA publications

Topic Sheets, Project Progress andHGCA guides are free to HGCA levy-payers. Project Reports and ResearchReviews are available from HGCA atcost. All HGCA publications are availablefree on the HGCA website www.hgca.com

Grain sampling a farmers guide(2003)

Grain sampling on-farm poster (2003)

The grain storage guide, 2nd edition(2003)

Grain sampling from field to buyer understanding variation (2004)

Wheat seed health and seed-bornediseases a guide ( 2004)

Wheat disease management guide(revised 2007) (available online atwww.hgca.com)

Wheat Disease Encylopaedia (2006)(available online at www.hgca.com)

CropMonitor www.cropmonitor.co.uk(also available at www.hgca.com)

Topic Sheet 91 (2006) Managing theFusarium mycotoxin risk in wheat

Project Progress 10 (2005) Reducing therisk of Fusarium mycotoxins in UK wheatproduction

Project Progress 13 (2006) On-floordrying to minimise grain spoilage

Project Report 297 (2003) Maximisingcontrol with fungicides of Fusarium EarBlight (FEB) in order to reduce toxincontamination of wheat

Project Report 383 (2006) Improving the

deposition and coverage of fungicides onears to control Fusarium ear blight andreduce mycotoxin contamination of grain

Project Report 394 (2006) Evaluation ofrapid test kits for deoxynivalenol (DON)

Project Report 413 (2007) Investigationof fusarium mycotoxins in UK wheatproduction

Project Report 415 (2007) Investigationof fusarium mycotoxins in UK barley and

oat production

Ongoing project 2726 Reducedfusarium ear blight and mycotoxins

through improved resistance (REFAM)

Other references and websites

Food Standards Agencywww.food.gov.uk

The UK Code of Good AgriculturalPractice to Reduce FusariumMycotoxins in Cereals (2007) FSAwww.food.gov.uk/multimedia/pdfs/fusariumcop.pdf

The UK Code of Good Storage Practiceto Reduce Ochratoxin A in Cereals(2007) FSAwww.food.gov.uk/multimedia/pdfs/ochratoxinacop.pdf

Retail oat products surveywww.foodstandards.gov.uk/multimedia/webpage/174922

Agricultural Industries Confederationwww.agindustries.org.uk

National Association of British andIrish Millerswww.nabim.org.uk

Maltsters Association of Great Britainwww.ukmalt.com

United Kingdom Accreditation Servicewww.ukas.org

For European Commission regulationssee http://eur-lex.europa.eu

Commission Regulation (EC) No401/2006 of 23 February 2006 layingdown the methods of sampling andanalysis for the official control of thelevels of mycotoxins in foodstuffs

Home-Grown Cereals Authority Caledonia House 223 Pentonville RoadLondon N1 9HY

www.hgca.comT 020 7520 3922 F 020 7520 [email protected]

HGCA 2007

263610/07J

Disclaimer

The Home-Grown Cereals Authority (HGCA) hasprovided funding for these guidelines but has not

conducted the research or written these guidelines.While the authors have worked on the bestnformation available to them, neither the HGCA norhe authors shall in any event be liable for any loss,

damage or injury howsoever suffered directly or

ndirectly in relation to the guidelines or the researchon which it is based.

Reference herein to trade names and proprietaryproducts without stating that they are protected

does not imply they may be regarded as unprotectedand thus free for general use. No endorsement ofnamed products is intended, nor is any criticismmplied of other alternative, but unnamed products.

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