Grain samplingguide for cerealsand oilseeds

2 GRAIN SAMPLING GUIDE

The value of grain sampliIntroductionUnderstanding the quality and condition of grain is crucial.Accurate sampling at each stage of the grain chain is required todevelop that understanding. It should help to reduce waste andminimise charges, claims and rejections.

This guide brings together the key requirements for effectivegrain sampling for everyone involved, from growing topurchasing. It seeks to minimise duplication of effort, maximisingefficiency. In this guide, sampling refers to the collection ofphysical grain and also sampling for moisture, temperature, pestsand moulds.

For many years, sampling grain has been important inmeasuring key quality parameters in combinable crops (egHagberg Falling Number, nitrogen content and specific weight).In recent years, however, other challenges (includingmycotoxins) have emerged, requiring the industry todemonstrate due diligence; samples of grain traded are part ofthat evidence. Grain sampling is, therefore, even moreimportant and must be undertaken using appropriate methodsat the most relevant points along the grain chain.

This guide has been endorsed by:

Best practice sampling at each stage of the grain chain1. Know the harvested quality: At harvest, analysis can only determine grain quality if sampling is representative of grain loads coming into store. Results from analysis of harvested grain will confirm if grain canmeets the proposed market's criteria.Targets for moisture and temperature of stored grain are set out in the Grain storage guide (cereals.ahdb.org.uk/grainstorage).Sampling and analysis at harvest indicate the action needed and timescale to meet those targets.

Page 8

2. Protect the harvested quality: During storage, sampling for temperature and moisture content isrequired to assess changes in physical condition and to verify that storage targets are met. Without effectivedrying and cooling, spoilage may occur and potential market opportunities may be lost.

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3. Know what leaves the store: At outloading from the store, representative samples taken as lorriesare loaded provide evidence of what has been dispatched. This is the best opportunity for the grower's andpurchaser's assessments of delivered quality to match.

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4. Know the quality received: At receipt, most buyers (merchants or processors) will sample from eachdelivery lorry, often using automated equipment, and should follow the best practice recommended byassurance schemes, such as TASCC.

Page 14

For more information, see the Cereal/OilseedSellers' Checklists and ensure anyone involved inselling combinable crops is familiar with the AICNo. 1 and FOSFA 26A contracts.

Grain marketingBefore harvest– Select appropriate varieties for the intended market

– Assess ability to segregate and store different varieties andqualities at harvest – is this sufficient to support the numberof varieties grown?

– Before marketing, understand your contractual obligationsand rights in relation to sampling

– When marketing quality grain, consider managing the feedbase price and premium separately – the majority of pricevolatility results from the feed base price

After harvest– Maintain communication with buyers on quality and variationso that grain can be allocated to the most appropriate user

– Where grain is sampled more than once on-farm, do notnecessarily rely on the highest quality analysis resultsbecause variation needs to be considered – any 'heap' ofgrain will have variation within it

– Take and retain a representative sample from each lorryloaded – these can support decision-making if a disputearises

ng

3

The value of grain sampling

Sampling termsIncremental sample – any single sample taken byspear, jug or other means, to be combined with others.

Aggregate sample – a large sample comprising allsmaller samples (ie incremental samples) taken at onepoint in the grain chain.

Representative sample – a final quantity of grain fromthe aggregate sample using appropriatemixing/sampling procedures (see page 17). This sampleis suitable for laboratory analysis.

Preparation 4

Why is sampling important? 6

Sampling at harvest 8

Sampling and monitoring in store 10

Sampling at outloading 12

Sampling at commercial intakes 14

Sampling and mycotoxins 16

Mixing and sub-sampling 17

Further information 18

Contents Page

Merchant:samplestaken fromex-harvestaggregatesamples orfrom on-farmstores forindication ofmarketability.Take at least 10

samples aseach lorry isloaded, toprovide two

1kgrepresentativesamples.

Monitor formoisture,temperatureand pests.

Combine

Processor

Tippingtrailer

Store

Lorry

Groupstorage

Drier/cleaner

Take at least 8samples fromeach lorry,totalling atleast 3kg. Mixand sub-sample.

Takesamples andassessmoisturecontent.

Take samplesand mix toproduce anaggregatesample

representing nomore than 100t.Analyse a

representativesample for

market criteria.

An example of samplingopportunities

4 GRAIN SAMPLING GUIDE

PreparationEquipmentAhead of harvest, ensure that all equipment is ready for use.

Equipment for sampling should include:

– Sampling spear

– Measuring jugs

– Sample bags capable of holding samples of 1kg of grain

– Sealed containers to hold samples of 5 –10kg of grain

– Labels that are suitable to be applied to bags and containers(if bags do not have white printed writing strips)

– Indelible pens – standard ballpoint ink can fade in a matterof months

– Moisture meter – ensure it is serviced and calibrated wellahead of harvest

– Record sheets

– Temperature probes – consider using automated systems

– Insect traps

All equipment should be kept clean, used only for grainsampling and serviced well in advance of harvest.

Containers must be capable of being sealed, to:

– minimise moisture loss

– prevent rodent access

– avoid contamination by dust and other grain

Container for gathering incremental samples Moisture meter

Multi-aperture sequential spear Temperature probe

5

PreparationFor moreinformation, see

AHDB Rodent controlon farms guide.

Rodent controlon farms

and responsible use of bait rodenticides

The pieces of equipment shown are examples andno recommendation of a specific model is implied

Sample storagePrepare a cool, dry area that is rodent-free to store grainsamples as required.

General safety information

– Ensure training, where appropriate, is given and allthose involved in sampling are aware of the riskareas

– Ensure all equipment is suitable for purpose andhas been checked to ensure fitness for use

– Ensure staff and visitors are aware of the vehicularmovements in and around the loading/unloadingareas

– Always ensure people sampling frombulk grain stores are accompanied

– No one should enter a closed silo

6 GRAIN SAMPLING GUIDE

Why is sampling importaAction:– Keep varieties separate– For each variety, identify areas likely toproduce grain of significantly differentquality (eg headlands or different fields) andkeep grain from these areas separate,wherever possible

Action:– Every trailer load should be sampled formoisture content

– Records should reflect where grain withinthe store came from to enable segregationby quality – this is required practice undermost assurance schemes

– Segregate grain lots that may be moreaffected by fungal disease or have quitedifferent specific weights

Action:– Aim to store in units of around 100t, inidentifiable units where possible

– Where grain is loaded out from large bulkstores, samples taken during lorry loadingprovide critical records of what has beendispatched

– Do not rely on the analytical resultsreported on grain samples drawn atharvest intake, other than as an indicationof marketing potential and the need fortaking action in the store

Action:– Sample after batch or continuous flowdrying to assess quality for markets

– With ambient or near-ambient drying,moisture monitoring is important to confirmthat the drying front has completed itspassage through the bulk

– Seek to treat similar batches of grain in thesame way

– Ensure drier settings are appropriate for thecommodity being dried – for example, donot use feed wheat settings for dryingmalting barley

– Aim to use the cooling section of the hot-airdrier to best effect and cool grain quicklyonce it is in long-term storage

Sources of variation Variation in growing grainGrain is extremely variable. Variation not only occurs across a farm orfield but even within a plant and within individual ears. The causes ofvariation can include soil types, local nutrient availability, differentvarieties or sowing dates, hedge and boundary effects and late tillering.

Variation in harvested grainTimeliness of harvest and prevailing harvest weather affect grain quality.During a harvest day, grain moisture content changes and trailer loads willdiffer due to natural variation in each harvested field.

Diseases may have affected only some parts of a field and possibly at alow level of incidence. This may or may not have led to potentialcontamination by, for example, mycotoxins.

Variation between undried and dried grainConsiderable variation, particularly in temperature and moisture content, canoccur within newly harvested grain stored on-floor before being conditioned.

When ambient or near-ambient air is used to dry bulk grain, a ‘drying front’moves up through the grain.

Grain stored after high temperature drying will vary less in moisture buttemperatures will generally be higher, requiring more urgent cooling effort.

Excessive heat generated within grain stored wet, or applied during hightemperature drying, can damage grain protein and germination. Over-dryingrapeseed can make it brittle and subject to a rapid increase in free fattyacids during storage. Certain characteristics are not affected, such asnitrogen content.

Variation within the farm storeSegregating grain into identifiable lots of similar quality maximises thelikelihood of achieving market specification. Identifying grain in relation tosamples taken at harvest is easier in smaller storage units, for instance, indiscrete bins up to 60t capacity.

Modern storage methods, however, often involve large bulks of grain storedat depths of up to 6–8m ‘pushed-up’ by specialist equipment. This meanseach trailer load will be moved up the grain face after tipping on the floor.This mixing is compounded as grain moves back down the slope duringoutloading. There is little chance of identifying individual trailer loads, or evensets of trailer loads, within such a bulk.

nt?

7

Why is sam

pling important?

Action:– Every effort should be made tosample grain safely at the point ofoutloading to provide a representativesample of the grain leaving the farm

– Check the contract, merchant annualterms or confirmation note for anyspecial terms relating to sampling

– Sample lorries at the point of deliveryaccording to standard protocols toproduce a 2.5–4kg aggregate

– Thoroughly mix and sub-sample graintaken from lorries at intake

Grain within any ‘lot’ (trailer load, bin, floor store, lorry,etc.) can be defined in terms of moisture content, specificweight, varietal purity, protein content and many othercharacteristics. However, grains are not identical and grainsampling seeks to enable a representative assessment ofthe characteristics of the lot.

Any one sample from a single point in a grain lot wouldprobably be unrepresentative of the characteristics of thetotal lot. A sampling programme aims to take sufficientsamples to reduce the variability and provide arepresentation of the total lot. The more samples that aretaken, the closer the average will be to accuratelyreflecting any characteristic.

Best practice is to take a series of incremental samplesfrom different parts of any given lot, blend themthoroughly and then take a sub-sample that can beanalysed to provide an average result to describe therelevant quality characteristics of the lot.

Predicting average values by sampling

The probability of achieving the mean result increaseswith the number of samples taken.

Number of samples0Pe

rcen

tage

pro

babi

lity

of a

chie

ving

mea

n re

sult

2 4 6 8

100

90

80

70

60

50

Hagberg Falling Number

Specific weight

Moisture content

Protein

Variation within loads delivered from farmThe effect of 'pouring' grain from a loading bucket and movementduring transit make it important to ensure effective sampling at thepoint of delivery. Internationally recognised standards exist for samplinglorries (see page 14), which specify numbers of separate samplesrequired from different load areas.

If samples have been accurately taken during loading from the farm andone representative sample has been provided to themerchant/processor, this sample could, in theory, suffice for all qualityassessments on delivery. However, unless a vendor assuranceprogramme is in place, all loads delivered to store or processor will besampled, usually using automated systems.

Sampling using an automatic sampler

Source: AHDB Cereals & Oilseeds Project Report 339

8 GRAIN SAMPLING GUIDE

Sampling at harvestWhy?Taking samples as stores are filled provides the bestopportunity to generate a representative sample. Aim to createa large aggregate sample (held in a clean dustbin or similarcontainer) formed from the incremental samples taken as thestore is loaded, which can be used by grain buyers to assesslikely market potential. Any sample drawn from this aggregatemust be representative of it, so it is important to mix and sub-sample using an appropriate method (see page 17).

Moisture contentThe first priority is measuring moisture content to determinewhat drying is necessary by sampling loads from each trailerfor moisture content. Under certain conditions of temperatureand moisture content, the production of the mycotoxin,ochratoxin A, may occur. Systematic prioritisation of drying is vital.

Once the drying process is underway, further sampling helpsmonitor progress towards the drying targets.

QualityTo determine quality, it is best to collect samples after dryingand cleaning. Samples taken as the grain goes into the storewill be more representative than those taken from the bulkonce the grain is in store. The only exception is for anycontaminant produced during storage (eg insects or storagemycotoxins).

Field mycotoxinsIf the mycotoxin riskassessment indicates thatfield mycotoxins may be aproblem or if the buyer hasa requirement forconfirmatory analysis oftoxin levels, it is at thisfarm intake stage thatrepresentative samplesshould be taken. See page 16.

How?Samples should be taken to represent identifiable units (lots) ofgrain in store. In practice, bearing in mind time constraints andmodern storage practice (eg bulk storage on floor and 'pushingup' often to depths of in excess of 6m), the target is to have atleast two 1kg samples that represent a unit of 100t of storedgrain.

This is achieved by taking many small individual samples(incremental samples) to form an aggregate sample – a largesample comprising all smaller samples. This will be much largerthan the 'final' samples retained as representative samples.The aggregate sample should be thoroughly mixed and sub-sampled (see page 17) to give the final representative sample.

If a bucket loader is used after grain conditioning to move graininto a bulk, representative samples can be taken using anautomatic bucket sampler (see page 13).

SafetyReversing and tipping trailers pose a safety risk.Only sample from stationary trailers and ensuredrivers are aware of your intention. It may besafer to sample tipped heaps than tipping trailers.

Labelling the samplesWhichever method is used, key information about the samplesmust be recorded by effective labelling of separate retainedsamples. Ideally, this should include:– Owner of the grain– Farm name– Store name– Quantity represented– Origin (field) – optional– Position in store (eg back left corner) or Bay/Bin identification– Date sampled– Variety– Moisture content (in store)– DON risk assessment score

Sample storageSamples taken from a trailer before batch or continuous flowdrying can be discarded.

Samples taken after drying, or from trailers prior to on-floordrying, can be retained for potential buyers to use to assessmarketability. For longer-term storage, ensure samples aresufficiently dry and kept in rodent-proof containers or store room.

There is no need to retain samples of stored grain once allpotential buyers have had the opportunity to take samples,provided each load leaving the farm is sampled.

For more information onmycotoxins risk, see

cereals.ahdb.org.uk/mycotoxins

The safe storage time calculator will help to identify grainin most urgent need of attention.cereals.ahdb.org.uk/grainstorage

9

Sampling at harvest

1. If grain is not cleaned or dried going into store, takesamples as the trailer arrives from the field.

2. Take two 500g samples from each trailer as it istipped into the store/silo, ideally, sample a quarterand three quarters of the way through tipping.

3. In, for example, a small plastic dustbin, thoroughlymix sub-samples from each trailer containing similargrain to form an aggregate sample representing nomore than 100t that can be traced to each flat store

bay, silo section or individual bin.

Method 1 – sampling off trailer forgrain conditioned on-floor or in-bin*

*If grain is wet (over 16% MC going into store), Method 1 can still be used but samples need to be dried gently before ‘bagging’ to avoiddeterioration. Spread samples thinly on a large sheet of paper or polythene and leave overnight in a warm place. Unless grain is at VERYhigh moisture (when on-floor drying is unlikely) this should be adequate to dry samples for testing.

1. Samples should be extracted from thecleaner/dryer outlet.

5. Repeat step 4 to produce a sample to retain.

2. Take frequent small (250g) samples according tothe flow so that at least 10 samples represent each100t (ie sample every 10t passing through the dryer

or cleaner).

3. Mix samples thoroughly to form an aggregatesample representing no more than 100t that can betraced to each flat store bay, silo section or bin.

4. Extract a 1kg portion from the aggregate sample by mixing it and taking a sample that best represents thewhole (see page 17). Do not take a single individual scoop from one point in the aggregate sample. At least take anumber of samples from points throughout the aggregate sample (eg five 200g samples) to form the test sample.

Method 2 – sampling afterconditioning into store

6. Put the test sample(s) in a plastic sample bag and label to identify the aggregate.

7. If the 100t lot is part of a flat store heap larger than 100t, ensure that the aggregate sample can be related tothe relevant part of the store. For grain stored in defined bays, identify by bay number/code.

9. In addition, the grower should draw and retain as many 1kg samples as are necessary for subsequent use andanalysis by potential buyers or merchants.

10. If the grower is confident that all grain in a single store, heap or bay will have broadly similar results (eg grainfrom same soil type) then one aggregate can be blended from several component 100t aggregate samples. This

enables an initial test to be performed on a large quantity of grain.

8. Collected reference sample(s) can be sent for analysis, with the rest of the aggregate kept for reference.

10 GRAIN SAMPLING GUIDE

Sampling and monitoring Why?During storage, grain is still a living ‘crop’ – respiring andsusceptible to infection by moulds and infestation by pests.Monitoring temperature and moisture content provides earlywarning of any change that may threaten crop quality.

MoistureRegular sampling for moisture content confirms whetherdrying targets are likely to be met.

High moisture can allow mites and moulds to develop. Therecommended level for longer-term storage is below 14.5%moisture content for cereals and 7.5–8% for rapeseed. This isparticularly important to prevent storage fungi (eg Penicilliumspecies) from producing ochratoxin A.

TemperatureRegular sampling for temperature confirms whether thetemperature/time targets are on track and identifies anytemperature rise that might indicate heating caused byinsect activity or water leaks.

Most storage insect pests cannot breed below 15°C and nonecan breed below 10°C. However, target temperatures need tobe achieved within a defined period to reduce graintemperatures below insect breeding thresholds before one lifecycle is completed. As grain will come into store well abovethese temperature thresholds, regular monitoring of storedgrain is important to follow the temperature reduction set outin the Grain storage guide.

PestsRegular sampling for pests enables early action to be takento overcome any risks identified.

Insects (primarily storage beetle pests) and mites can causerejection in the marketplace. They can be prevented fromestablishing in stored grain by conditioning grain to reducemoisture and temperature. Moisture is of primary importancefor mite breeding; temperature for insect breeding.

For more information on grainstorage, see the Grain storage

guide for cereals and oilseedscereals.ahdb.org.uk/grainstorage

MycotoxinsIf grain has been harvested 'dry', or has been dried quickly,storage mycotoxins (such as ochratoxin A) should not be a risk,unless water has contacted the grain from the store structure.

Legally, all producers should know whether grain for humanconsumption meets the food safety standards for thepresence of the fusarium mycotoxins, DON, ZON, T2 and HT2(see page 16). Many processors will require this information,especially at the start of each new harvest year. Samples takenin store may be used to provide this information.

QualityKey quality parameters will need to be assessed by trade-assured testing facilities which may be provided by a merchantor other independent testing laboratory. Depending on themarket, such tests may include:– Protein/nitrogen quantity– Specific weight– Hagberg Falling Number– Germination

Most quality parameters do not change during storage. Thereis, therefore, no need to extract samples for such analyses ifeffective sampling has taken place at intake and the location ofindividual sampled loads (or lots) can be accurately identifiedwithin the store.

Where prior sampling has not been undertaken, manypurchasers/potential purchasers will wish to assess quality in-store using, for example, a multi-aperture spear (ideally 3–5apertures). Such sampling is less likely to be representative ofa given bulk than samples taken as the store is loaded – aspear just 1.5–2.0 metres long cannot reach through deeperbulks/bins.

The impact on risk of any particular temperature andmoisture content combination can be assessed usingthe safe storage time calculator.cereals.ahdb.org.uk/grainstorage

Safety– Anyone sampling from a grain bulk should beaccompanied

– Attention should be paid to the presence of loading equipment, lorries and/or trailers

– No one should enter a closed silo

in store

11

Sampling and m

onitoring in store

How?MoistureWhen grain is dried ‘in situ’ (ie on-floor or in-bin), this isgenerally achieved by passing a high volume airflow upthrough the grain. This effectively 'pushes' a drying frontup from lower layers towards the surface – a process thattakes up to two weeks.

Moisture sampling monitors progress of the drying front.This can be achieved by sampling and testing grain nearthe top of the bulk/bin or with an automatic sensorinserted into the grain. The information gathered confirmswhen the drying front has completed its movement anddrying equipment can be turned off.

Monitor for moisture content at several locations (thesame each time). An increase in moisture content in alocalised area of 2% or more in a week may indicatecondensation, leaks, hot spots or insects. Record moisturecontent at least once each month during winter.

Annual calibration of moisture meters is essential. Errorsare frequently +/- 0.5% and can be greater in very wet,very dry or freshly harvested grain. Take as many samplesas possible and determine moisture content without delay.Keep samples in a watertight container with minimum freeair space and at a steady air temperature. Mix each samplethoroughly before testing.

TemperatureMonitor every few days until the target temperature isreached and then every week. Always record at the samelocation. Measurements must be taken where coolingtakes longest, eg furthest from the fan in blowingsystems, usually 0.5m beneath the surface and centrallybetween ducts.

In larger stores, consider permanent temperature probesinstalled in a grid pattern across the bulk. Moderninstallations enable constant remote monitoring, includingvia smartphone. Electronically recorded data also allowstrends to be observed over time.

Any temperature rise over 1˚C should be investigated, as itcould indicate the presence of fungi, sprouting,development of pests or a leaking roof.

PestsWhile pests in stored grain can be detected by examiningphysical samples of grain drawn from a bulk or bin, it is avery laborious process. Traps have been shown to be morethan ten times as effective as sampling at detecting lowlevel populations of insects and mites. Some traps aredesigned for use in the store, others for use within thegrain bulk.

Positioning traps both on the grain surface andapproximately 5–10 cm below (approximately 4–5 metresapart) will provide the greatest likelihood of detecting allspecies of stored product insects and mites at the earliestopportunity.

Monitor for pests weekly until grain reaches the targettemperature and then monthly, providing it remains at thetarget temperature, until spring when temperatures riseand insects become more active. Then revert to weeklymonitoring. Traps should be accounted for each time theyare examined and a permanent record of the contentsshould be kept.

Record-keepingKeeping a record of each monitoring activity both providesevidence of due diligence and allows trends, particularly intemperature and moisture, to be spotted.

Electronic systems provide a simple way to record allmeasurements and assessments made during storage. Asan alternative to time-consuming probing or samplinggrain, fixed probes/sensors can be installed in stores tomonitor conditions in store constantly (eg moisture andtemperature).

It is important that any pests found are correctlyidentified. Refer to the Grain storage guide or

the poster: Insects and mites in stored grain andgrain stores. cereals.ahdb.org.uk/grainstorage

It is important that any pests found are correctly identified. Field insects may be found in the grain shortlyafter harvest but these will die out in the store.

Saw-toothed grain beetleOryzaephilussurinamensis

Only develops ondamaged surfaceof grain. Very active andeasy to trap.

Rust-red grain beetleCryptolestesferrugineus

Penetrates grainthrough minutecracks. Can fly in hot UKsummers.

Grain weevilSitophilusgranarius

Develops insidethe grain. Causes heating.Difficult to find.

Common primary insect pests

24 HGCA Grain storage guide for cereals and oilseeds

Pest identification

25

Pest identification

Can increase rapidly and damage grain stored at temperatures above 15˚C.

Cosmopolitan food miteLepidoglyphusdestructor

Surface feederusually presentin low tomoderatenumbers.

Grainstack mite Tyrophagus longiorInitial infestationsoften occurduring bulkdryingoperations.Requires highmc andtemperature.

Flour mite Acarus siroIndicates bulkmoisture contentis higher thanrecommended.Internal feederwhich can buildup massivepopulations.

Pest mites Normally only a problem on damper surface of dry bulk if moisture content targets are met in therest of the bulk.

GamasidaeLong-legged fastmovers may prey onpest mites. Individualsmay also be bloodfeeders on rodents.

Predatory miteLarge numbersindicate hightemperatures andpreviousinfestations.

Predatory & other mites Large numbers indicate high temperatures and previous infestations.

White-shoulderedhouse mothEndrosissarcitrella

Slow todevelop in oldgrain or feedresidues.

Moth larvaDistinguishedfrom beetlelarvae by darkhead capsule.

Brownhouse mothHofmannophilapseudospretella

Oftenassociatedwith animalfeeds.

Moths

Lesser grain borerRhyzoperthadominica

Eggs laid on grainsurface, larvaeburrow inside todevelop.

Rust-red flour beetleTriboliumcastaneumRequires a highproportion ofdamaged grains tothrive. Frequentlyfound in animalfeed mills.

Rice and maize weevilsSitophilusoryzae/zeamaisMainly associatedwith importedfeedstuffs.Canmove into storedgrain. Eggs laidinside grain.

Other primary insect pests Occasionally found on UK grain but require high temperatures and do notoverwinter well.

Foreign grain beetleAhasverus advena

Increasinglycommon inUK. Very mobileand a commoncause ofrejection.

Fungus beetleseg Cryptophagusspecies

Frequent indamp, mouldyresidues and canwander intostored grain.

Hairy fungus beetleTyphaea stercoreaAssociated withstored straw, hayand damp residues.Develops insidethe grain. Causes heating.Difficult to find.

White-marked spider beetlePtinus fur

Numbers cantake years tobuild up. Cansurvive longperiods in aninactive form.

Plaster beetleLathridiidae

Very small blackbeetles whichflourish in damp,mouldy residues.

Australian spider beetlePtinus tectus

Seldom found inUK grain,but survives instructure ofwarmer stores.

Secondary insect pests Cannot complete their life cycles at 14.5% moisture content or below. Feed primarily onfungi. Can invade grain stores in large numbers from outside and feed directly on grain.

May be seen flying in summer. Webbing produced by larvae may clump grains together.Mainly occur on surface of bulk, also infest and breed in debris.

– wingedCan be found inspectacularnumbers,especially aroundedges of grainbulk. Pest statusnot clear.

Clover weevilSitona speciesOther non-damagingspecies includethe groundbeetle and thenarrow-neckedharvest beetle.

– winglessRequiredamperconditions,ubiquitousin UK.

Booklice Non-pest speciesConsiderable numbers may build up at grain surface, mainlyin winter. Can be clearly seen running over storage structures.

12 GRAIN SAMPLING GUIDE

Sampling at outloadingWhy?Best practice, to which the industry should aspire, is to takeand retain samples from each lorry load before it leaves thefarm. These samples will not be contractual for the purposes ofthe determination of quality or condition at the delivery pointbut they may help if problems arise.

The quality and quantity of grain leaving the farm represent theresult of a year's work and this is the best opportunity for thegrower's assessment and the purchaser's assessment ofdelivered quality to match. Taking and retaining samples is alsoa requirement of some assurance schemes.

Labelling the samplesAll samples must be labelled with basic information, including:– Farm name– Store name/number– Bin number– Variety– Date– Time– Vehicle registration and trailer number

Sample storageSamples should be stored in airtight containers (for example,polythene bags or plastic boxes) in a cool, dry place safe fromrodent attack.

These samples should be retained until payment has beenreceived for the loads to which the samples relate.

Safety– Do not attempt to climb on top of lorries, unlessthere is special provision

– Be aware of risks around loading equipment andvehicles at outloading

– Wear hi-vis clothing at all times when working around loading lorries

Avoiding the mostcommon problemsassociated withcereals salescontracts

Produced by AHDB Cereals & Oilseeds, on behalf of the Cereals Liaison Group

2. Agreeing the contract� Check the price offered orcalculation method

� Check delivery terms� Consider asking for special clauses� Discuss possible destinations forthe grain

� Exchange contact numbers� Ensure you receive the writtenconfirmation promptly

3. Delivering thecontract

� Keep a representativesample of each load

� Check lorries forcleanliness

� Ask to be notified ofany claims before aload is tipped

1. Before agreeing acontract

� Grow for a market� Check assurancescheme requirements

� Manage pricevolatility

Cereal Sellers’ Checklist

Avoiding the mostcommon problemsassociated withoilseed salescontracts

Produced by AHDB Cereals & Oilseeds, on behalf of the Cereals Liaison Group

1. Before agreeing acontract

� Grow for a market� Check assurancescheme requirements

� Manage pricevolatility

2. Agreeing the contract� Check the price offered orcalculation method

� Understand the adjustments scale� Discuss possible destinations forthe grain

� Consider asking for special clauses� Exchange contact numbers� Ensure you receive the writtenconfirmation promptly

3. Delivering thecontract

� Keep a representativesample of each load

� Check lorries forcleanliness

� Get a receipt for everyload despatched

Oilseed Sellers’ Checklist

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Incrementalsample

Aggregate sample

Combine at least ten 200g samples toproduce an aggregate sample.

Mix the aggregate sample and sub-sample to produce the

representative sample(s) (see page 17).

Representativesample

Retain

See the CerealSellers'Checklist andthe OilseedSellers'Checklist formoreinformation.

How?The sampling method depends on the equipment used forloading the lorry. In all cases, sampling should follow standardprotocols to maximise the validity of retained outloadingsamples.

For a 30 tonne lorry-load of grain, take at least 10 samples of200g as the grain is loaded. This provides a 2kg aggregatesample.

13

Sampling at outloading

Automatic bucket samplerManually collecting a sample from each bucket as it isloaded is time-consuming. Automatic samplers areavailable that extract a small amount of grain from eachbucketful during the process of loading a lorry.

Such samplers collect a maximum of between around0.8kg and 2kg of grain until full. It is important to choosea product that can ultimately deliver two 1kg sub-samples for each lorry-load. If less than 2kg is collected,while still a representative sample, it is likely to give lessaccurate results than a larger sample.

The sampler is robust and simple with no moving parts.All the individual bucket samples collected as the lorry isloaded are mixed in the sampler to form an aggregatesample. All the operator has to do is empty the samplerafter each lorry has been loaded and bag the samples.

In AHDB Cereals & Oilseeds-funded tests, this samplingtechnique proved easy to use, did not delay loading anddid not compromise operator safety. The test results of‘bucket’ samples agreed well with samples collectedfrom lorries at delivery when best practicerecommendations were followed by both the farmerand the receiver.

Sampling from spout loadingFor grain being loaded into a lorry from a conveyingsystem, it is best that grain is sampled at a point closeto the loading location, where samples may be drawnsafely. In some cases, an 'interrupter' plate can beinserted into conveying tubes.– Collect at least ten 200g samples– Combine these incremental samples into a single2kg aggregate sample in a bucket

– Mix the aggregate sample and divide into two 1kgrepresentative samples (see page 17)

Sampling from a grain heapWhen loading bulk/on-floor stored grain, the grainneeded for the next lorry could be pre-positioned into aseparate heap. This can be sampled with a conventionalgrain spear preferably multi-aperture).– Take at least ten 200g samples– Combine these incremental samples into a single 2kgaggregate sample in a bucket

– Mix the aggregate sample and divide into two 1kgrepresentative samples (see page 17)

Sampling from the loading bucketSampling from the loading bucket is the best methodto obtain a representative sample but manual samplingideally requires a second person. A safer methodwould be to use an automatic bucket sampler.– Scoop samples from the grain in each bucket loaded– Combine these incremental samples into a single2kg aggregate sample in a bucket

– Mix the aggregate sample and divide into two 1kgrepresentative samples (see page 17)

14 GRAIN SAMPLING GUIDE

Sampling at commercial iWhy?All processors of any size sample and analyse grain at intake todetermine its quality and whether it has met the agreedcontractual requirement and specifications. Additionally, mostwill test at intake for the presence of mycotoxins, particularly atthe start of the new harvest season.

The testing done by processors may be quantitative (egmoisture, protein and Hagberg Falling Number) or qualitative(eg taint or visual appearance). Different delivery points (animalfeed manufacturers, millers, maltsters, breakfast cerealmanufacturers, exporters, etc.) will carry out different tests toassess quality but sampling methods will tend to be similar,especially in larger premises.

The biggest sampling issue with incoming loads of grain is thatquality across the vehicle may not be uniform. Vehicles aresometimes loaded with grain taken from different locations inthe grain store and the stored grain may not be uniformlymixed. Heaping in the vehicle, caused by bucket loading, doesnot always level out during haulage and this can bias sampling.

How?

The example below is the recommended ISO samplingmethod for a 30 tonne bulk vehicle load of grain at an intakepoint (ISO 24333:2009). The circles represent where a spearsample should be taken.– Ideally, eight samples should be taken (three samples forlorries of 15 tonnes or less)

– The spear must be long enough to sample the whole depthof grain

– Sampling position is more important than the number ofsamples taken from each load: the lorry should be positionedso that most of the load is accessible

Automatic samplersVirtually all medium to large processors sample grain onarrival using a mechanised spear that is programmable oris controlled from the laboratory or intake office via ajoystick. The spear draws a sample up through the core ofthe load, having sensed the bottom of the trailer. Thisminimises the amount of fine/small grains in the sample,which would adversely bias the amount of screenings inthe sample.

In flight from the lorry to the laboratory, separation of thegrain is likely to occur; the smaller grains and screeningswill arrive earlier than the larger grains. It is, therefore,particularly important to mix the sample thoroughly beforetaking analytical samples for testing.

Hand-held samplersSmaller processors may sample using handheld manualspears. These may also be used at larger facilities whenbreakdown of the automatic sampler occurs.

If sampling manually, a spear should be used that willcollect samples from different depths and collect about500g per sampling point – this may require more than oneinsertion per sampling point.

The AIC No. 1 contract states that deliveries shall besampled by the receiver at the final consignment point inaccordance with the procedure laid down in the ISO 24333Standard or any any amendments to it. Check the contract,merchant annual terms or confirmation note for any specialterms relating to sampling.

ntakes

15

Sampling at com

mercial intakes

Mixing and sub-samplingMost automatic sampling equipment produces anaggregate sample of 6–8 kg. To ensure representative sub-samples are used for testing, this sample must bethoroughly mixed, using methods similar to thosedescribed on page 17.

CleaningCompanies will have a policy on whether screenings andadmixture should be included when a sample is tested.This should be made known to the seller and form part ofthe contract. This will take into account whether thecalibrations for specific tests were developed using cleansamples and whether admixture could cause damage to orblock equipment.

Cleaning can be carried out using sieves, for example,those used to determine screenings, or more specialistequipment may be used. Samples should be labelled toindicate whether or not they have been cleaned.

GrindingFor some methods, whole grains are not suitable and thesample is ground. Individual grains with extreme valueswill affect the result if small samples are used. To reducethis effect, a relatively large sample should be ground.

Most grinders cause particle separation. Bran or huskgrind at different rates to endosperm and are often on thesurface of the ground sample. Mixing of the groundsample is essential.

To prevent cross-contamination, grinders should becleaned or flushed between samples and cleanedthoroughly at the end of the day.

Storage and labellingSample containers must limit moisture loss and avoidcross-contamination with other samples. For storage,containers should be full and plastic bags should have theair expelled from them to prevent moisture loss andspillage.

Adequate labelling is important to allow samples to betraced and the results assigned to the correct samples.Labelling of lids should be avoided, as these can beswapped between samples. The length of time samples areretained will depend on company policy and/or contracts.

Laboratory testingExact testing requirements will be specified in contractsbut, for some tests, a reference procedure may be used(eg ISO 712:2009 for moisture determination). Most flourmills and maltings will use modern alternative equipmentfor some tests (such as NIR) but these will be traceable tothe reference procedures.

Flour mill intake laboratories take part in the nabimproficiency scheme (or equivalent), maltings participate inthe Malting Analytes Proficiency Scheme (MAPS) andTASCC laboratories also take part in proficiency schemesto ensure conformity of results throughout the year.

For informationon the visual

inspection of grain,see the AHDB Cereals& Oilseeds poster'Inspecting grain fordefects andimpurities'.

See cereals.ahdb.org.uk/graintesting for moreinformation and training tools for grain analysts.

Sample storage

16 GRAIN SAMPLING GUIDE

Sampling and mycotoxinsMycotoxinsMycotoxins are toxins produced by fungi that infect cropsand/or grow on grain.

In cereals, contamination by mycotoxins can result from eitherfield-borne infections or from fungi that develop in stored crops.

Field mycotoxins– Infection of ears by Fusarium species can result in mycotoxindevelopment

– The risk assessment for fusarium mycotoxins in wheat shouldbe completed

– Mycotoxins formed before harvest are stable and likely toremain during storage but not increase

Legal limitsLegal limits exist for the three principal mycotoxins (DON, ZONand ochratoxin A) that may occur in cereals and cereal productsintended for human consumption. Guideline limits also exist forcereal intended for animal feed.

The EU Commission has now published a Recommendation forT2 and HT2 establishing indicative levels. It also sets outrequirements for industry and authorities in terms of monitoringagainst these levels and what investigations must beundertaken when repetitive results above the indicative levelsare found. These levels are not, however, maximum limits, nor isthere any suggestion that they represent a risk to food safety.

It is the responsibility of all food business operators (includingfarmers, merchants and processors) not to place on the marketany cereal or cereal products that exceed the legal limits. Thismeans that all sellers must be able to demonstrate due diligencein determining the levels of mycotoxins that are present.

The current legal limits for the principal mycotoxins in grain forfood markets are:– Deoxynivalenol (DON): 1,250 ppb (unprocessed wheat andbarley), 1,750 ppb (unprocessed oats)

– Zearalenone (ZON): 100 ppb (unprocessed wheat, barley andoats)

– Ochratoxin A (OTA, OA): 5 ppb (unprocessed cereals)

Individual processors may set contractual maximum levels,depending on the type of product, such as baby foods orbreakfast cereals.

Sampling for mycotoxinsSampling specifically for mycotoxins requires a demandingregime because the distribution is not likely to be uniformwithin a stored bulk. Fungal growth and associated mycotoxinscan be very localised,especially for thestorage mycotoxin,ochratoxin A.

The sampling protocolsin this guide have beendesigned to meet themore demandingrequirements ofsampling formycotoxins, as well asother aspects of grainassessment andmonitoring.

Storage mycotoxinsThe main fungus with the potential to cause problems instored grain in the UK is Penicillium verrucosum. Under certainconditions (18% moisture content and above), this fungus canproduce the mycotoxin ochratoxin A.

For more information, see cereals.ahdb.org.uk/mycotoxins

For more information ongrain storage, see the

Grain storage guide for cerealsand oilseedscereals.ahdb.org.uk/grainstorage

Information Sheet 40Spring 2015

HGCA publications are free to levy payersTo join the mailing list, contact: subscriptions@hgca.ahdb.org.uk

© Agriculture and Horticulture Development Board 2015. All rights reserved.

While the Agriculture and Horticulture Development Board, operating through its HGCA division,seeks to ensure that the information contained within this document is accurate at the time ofprinting, no warranty is given in respect thereof and, to the maximum extent permitted by law, theAgriculture and Horticulture Development Board accepts no liability for loss, damage or injuryhowsoever caused (including that caused by negligence) or suffered directly or indirectly in relationto information and opinions contained in or omitted from this document.

Reference herein to trade names and proprietary products without stating that they are protecteddoes not imply that they may be regarded as unprotected and thus free for general use. Noendorsement of named products is intended, nor is any criticism implied of other alternative butunnamed products.

HGCA is the cereals and oilseeds division of the Agriculture and Horticulture Development Board.

Risk factorsRegion – DON and ZON levels inwheat tend to be highest in southernand eastern England. Higherhumidity in coastal areas mayincrease risk. Information fromwww.cropmonitor.co.uk may beused to assess overall risk on ayearly and regional basis.

Previous crop – Crop residue on thesoil surface is the major source ofinoculum. The greatest risk is aftergrain maize or forage maize.Rotations should aim to minimisewheat sown after maize.

Cultivation – Complete burial ofdebris by ploughing is most effectiveat reducing the risk, while risk ishighest with direct drilling. Intensivenon-inversion tillage (three or morepasses with discs or tines) is moreeffective at reducing risk thanreduced non-inversion tillage (one ortwo passes).

Instructions– Enter details of the store intowhich wheat from a single ormultiple fields has been placed.

– Enter individual field names;fields can be grouped if grownwith the same agronomy andsubject to the same rainfall.

– For each field, enter theappropriate risk score for thefactors stated.

– Record the final risk score onthe grain passport. If a loadcontains grain from multiplefields, record the highest scoreon the passport.

Wheat variety – The risk assessmentincludes varietal resistance based onthe HGCA Recommended List ratingfor fusarium ear blight(www.hgca.com/varieties)

T3 ear fungicide – Using anappropriate dose rate of a T3 earfungicide with activity againstfusarium and/or mycotoxinproduction reduces the risk. SeeHGCA Information Sheet 38 forinformation on fungicide performanceand activity.

Rainfall at flowering – Wet weatherpromotes fusarium development. Thescore is based on total rainfall duringflowering (GS59–69 – full earemergence to end of flowering).

Rainfall pre-harvest – Based on totalrainfall from GS87 (doughdevelopment stage/start of ripeningstage) to harvest.

Always consider your local conditions andconsult a professional agronomist, if necessary.

The need for accurate risk assessmentThere are legal limits for fusariummycotoxins deoxynivalenol (DON)and zearalenone (ZON) in wheatintended for human consumptionand guidance limits for grain forfeed. The owner (farmer, merchant

Assurance schemesCrop assurance schemes aredesigned to help farmers complywith food laws. They include anaudit of the risk assessment and anHGCA risk assessment score isrequired on the grain passport.

or processor) is legally obliged toensure the grain is safe for humanconsumption. For information on thecurrent legal limits, please seewww.hgca.com/mycotoxins

Action– Follow best practice to minimisefusarium mycotoxins in cereals

– Use this sheet or the online tool toassess risk of fusarium mycotoxins.

– Assess risk pre-flowering andconsider T3 fungicide (ear spray).

– Take accurate measurements ofrainfall at flowering and pre-harvest.

– Calculate final risk score at harvestand record on grain passport.

– Check end-user requirements todetermine whether mycotoxintesting is required.

Further informationDhan Bhandari, AHDBdhan.bhandari@ahdb.org.uk

Simon Edwards, Harper AdamsUniversity sedwards@harper-adams.ac.uk

For other relevant publications,tools, videos and furtherinformation, please seewww.hgca.com/mycotoxins

For rainfall information from theMet Office, please seewow.metoffice.gov.uk

Risk assessment for fusariummycotoxins in wheat

Information Sheet 40Spring 2015

Mycotoxin testing

Mixing and sub-sampling

17

Sampling and m

ycotoxins / Mixing and sub-sam

pling

A large aggregate sample of grain will include grains of different sizes and quality. It is important to ensure, as far aspossible, that all grains in the aggregate have an equal chance of being included in any sub-sample drawn from it.

Step 2. Produce the representative samples.A number of methods of varying complexity can be used for sub-sampling an aggregate sample after it has beenthoroughly mixed. These include 'coning and quartering' and sample dividers, such as a cone-shaped divider, a rotarymechanical divider or a riffle divider. Details for using such equipment are given in ISO24333; the only constraint is thatriffle dividers should not be used for samples of less than 2kg. The 'coning and quartering' method is described below.

Step 1. Mix the large aggregate sample as thoroughly as possible.This can be achieved by using either a large drum with a securely fitting lid or by hand-mixing the aggregate on aclean floor area.

Note: when retaining selected quarters, it is imperative that ALL the material in the quarter, including admixture, iscollected.

If mixing by hand,after tipping thegrain from its originalcontainer holding theaggregate (eg a largeplastic dustbin) ontothe floor, it can bemixed using a cleanshovel/scoop.

If using a drum mixer,ensure it is no more than halffull, roll the drum along itsaxis and invert it at least fivetimes. Sub-samples of around1kg can then be extracted bytaking, for example, fivesamples of approximately200g from different positionsin the drum.

1. The heap of tipped grain will takethe rough form of a cone – it can bedescribed as having four quarters.

2. Select two opposite corners (egA and D) and remove the other twoquarters and return them to theoriginal container.

4. Repeat until the size of one of thequarters is the equivalent weight ofthe final sample required (eg 1kg).

AC

D

B

A

C

D

B

A D

B + C

A+D

Mixing grain

3. Mix samples A and D again toform a new cone of grain.

18 GRAIN SAMPLING GUIDE

Further information

Grain storageG52 Grain storage guide for cereals and oilseeds, 3rd

edition (2011)

P01 Insects and mites in stored grain and grain stores(poster)

Grain testingP06 Inspecting grain for defects and impurities (poster)

G21 Grain testing – standards for testing (2004)

Fusarium mycotoxinsG69 Guidelines to minimise risk of fusarium

mycotoxins in cereals (2016)

IS40 Risk assessment for fusarium mycotoxins inwheat (2015)

Sellers' ChecklistsCSC2016 Cereal Sellers' Checklist (2016)

OSC2016 Oilseed Sellers' Checklist (2016)

Project ReportsPR515 Investigation into the specific weight differences

between wheat varieties tested in the HGCARecommended List and commercially-growncrops from 2007–2012 (2013)

PR514 Survey of current agronomic practices influencingfree fatty acid content in oilseed rape during the2011/12 season (2013)

PR510 Ensuring that UK cereals used in malting, millingand animal feed achieve food and feed safetystandards (2013)

PR464 Food safety review of UK cereal grain for use inmalting, milling and animal feed (2009)

PR426 Research to develop practical user guidelines tomaximise the accuracy of moisture meters (2008)

PR407 Assessment of three commercial automatic grainsamplers fitted to front loader buckets (2006)

PR362 Development and validation of on-farm samplingprotocols: Assessment of an automatic bucketsampler for use during out-loading (2005)

PR349 A national grain sampling and analysis system forimproved food marketing and safety (2004)

PR339 Grain sampling and assessment: Sampling grainin lorries (2004)

PR325 Developing and validating on-farm samplingprotocols: sampling in store and during out-loading (2004)

PR301 Development and validation of on-farm samplingprotocols for collection of marketing (quality)samples at harvest (2003)

Research ReviewsRR50 Grain sampling methods to achieve consumer

confidence and food safety (2003)

Publications and details of projects funded by AHDB Cereals & Oilseeds are all available atcereals.ahdb.org.uk

AHDB Cereals & Oilseeds information

19

Further information

Other informationnabim PublicationWheat and flour testing (nabim, 2011)

Rural Payments Agency PublicationExplaining the Common Agricultural Policy of theEuropean Communities for the Basic Methods forSampling Cereals (Leaflet Number IM(C)18, August 2013)www.rpa.defra.gov.uk

WebsitesAgricultural Industries Confederation (AIC):www.agindustries.org.uk

BSI Standards: http://shop.bsigroup.com

Federation of Oils, Seeds and Fats Associations (FOSFA):www.fosfa.org

Grain and Feed Trade Association (GAFTA):www.gafta.com

Maltsters' Association of Great Britain (MAGB):www.ukmalt.com

National Association of British and Irish Millers (nabim):www.nabim.org.uk

NFU: www.nfuonline.com

Red Tractor Farm Assurance:www.assurance.redtractor.org.uk

Scottish Quality Cereals (SQC): www.sfqc.co.uk

British and International StandardsBS EN ISO 24333:2009 Cereals and cereal products –sampling

This International Standard is often quoted by the UK'sgrain industry quality schemes and by trade samplingstandards.

In its introduction, the Standard describes sampling as aprocess needing methods and equipment suited to thepurpose. Quite rightly, as any interpretation will be futileif the sample failed to represent the lot appropriately.

This is why sampling is so important and should only beentrusted to correctly trained people with equipment thatis suited to the task.

The Standard runs to over 28 pages and the followingsummary of points is suggested as relevant to the UKgrain trade.

1. For static bulks, manual probes can only be used to adepth of 2m. For grain stored deeper than 2m, onlymechanical or suction sampling devices should beused.

2. Also for static bulks (to include silos or warehouses) aminimum of 15 individual samples must be taken toprovide a laboratory sample to represent 100t of astatic grain bulk. For smaller lots, eg lorries up to 30t,eight samples must be taken and each individualsample must weigh a minimum of 400g.

3. Sampling grain for contaminants requires a differentsampling frequency/total aggregate size than forother analyses. As examples, 1–3kg is the minimummass for the laboratory sample used for otheranalyses; 10kg is required for ochratoxin A; 1kg forpesticides, heavy metals, dioxins, etc.; and 3kg forother contaminants (except DON/ZON, etc. that canbe of 1kg).

4. No laboratory sample should weigh less than 1kg.

5. All laboratory samples must be thoroughlyhomogenised.

BS EN ISO 542:1990 Oilseeds – sampling

Commission Regulation (EC) No 401/2006 of 23February 2006. Laying down the methods of samplingand analysis for the official control of the levels ofmycotoxins in foodstuffs.

Acknowledgements

This guide, funded by AHDB Cereals & Oilseeds, was written byDr Ken Wildey, Technology for Growth, and Geoff Dodgson,Ware Anthony Rust.

AHDB is grateful to many people who have commented on draftversions of this guide, including: Dr Dhan Bhandari, Dr Susannah Bolton, Jess Burgess, Anna Farrell, Dr Vicky Foster,Rebecca Geraghty and Leo Townsend and Jack Watts, AHDB;Paul Rooke and Garry Rudd, AIC; Dr Jon Knight, HDC; Colin West, MAGB; Alex Waugh and Martin Savage, nabim; Guy Gagen and Michael Hambly, NFU; Peter Loggie, NFUS;Catherine Lehane, Red Tractor Assurance; Patricia Erwin, UFU;and David Houghton, Martin Robinson, Guy Smith, Rad Thomasand Jonathan Tipples, AHDB Cereals & Oilseeds Board/Committee members.

Photographs of automatic bucket sampler (page 13) courtesy ofClaydon Yield-O-Meter Ltd.

Edited by Dr Emily Boys, AHDB.

AHDB Cereals & OilseedsStoneleigh ParkWarwickshireCV8 2TL

Publications orders0845 245 0009cereals.publications@ahdb.org.uk

Autumn 2013Electronic version can be downloaded at cereals.ahdb.org.uk/publications

AHDB Cereals & Oilseeds is a division of the Agriculture and Horticulture Development Board (AHDB).

© Agriculture and Horticulture Development Board 2016

All rights reserved

G60

While the Agriculture and Horticulture Development Board seeks to ensure that the information contained within this document is accurate at thetime of printing, no warranty is given in respect thereof and, to the maximum extent permitted by law, the Agriculture and HorticultureDevelopment Board accepts no liability for loss, damage or injury howsoever caused (including that caused by negligence) or suffered directly orindirectly in relation to information and opinions contained in or omitted from this document.

Reference herein to trade names and proprietary products without stating that they are protected does not imply that they may be regarded asunprotected and thus free for general use. No endorsement of named products is intended, nor is any criticism implied of other alternative, butunnamed products.