HGCA Grain sampling guideHGCAGrain sampling guide2 HGCA Grain sampling guideThe 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 graincanmeets the proposed market's criteria.Targets for moisture and temperature of stored grain are set out in the HGCA Grain storage guide (www.hgca.com/grainstorage).Sampling and analysis at harvest indicate the action needed and timescale to meet those targets.Page 82. 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. Page 103. 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.Page 124. 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 14For more information, see HGCA's 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 priceAfter 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 disputearisesng3The value of grain samplingSampling 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 4Why is sampling important? 6Sampling at harvest 8Sampling and monitoring in store 10Sampling at outloading 12Sampling at commercial intakes 14Sampling and mycotoxins 16Mixing and sub-sampling 17Further information 18Contents PageMerchant:samplestaken fromex-harvestaggregatesamples orfrom on-farmstores forindication ofmarketability.Take at least 10samples aseach lorry isloaded, toprovide two1kgrepresentativesamples.Monitor formoisture,temperatureand pests.CombineProcessorTippingtrailerStoreLorryGroupstorageDrier/cleanerTake at least 8samples fromeach lorry,totalling atleast 3kg. Mixand sub-sample.Takesamples andassessmoisturecontent.Take samplesand mix toproduce anaggregatesamplerepresenting nomore than 100t.Analyse arepresentativesample formarket criteria.An example of samplingopportunities4 HGCA Grain sampling guidePreparationEquipment Ahead 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 510kg 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 trapsAll 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 grainContainer for gathering incremental samples Moisture meterMulti-aperture sequential spear Temperature probe5PreparationFor moreinformation, seeRodent control inagriculture an HGCAguide.The pieces of equipment shown are examples andno recommendation of a specific model is impliedSample 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 silo6 HGCA Grain sampling guideWhy 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 possibleAction: 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 weightsAction: 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 storeAction: 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 storageSources 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 frontmoves 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 68m 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?7Why is sampling 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 2.54kg aggregate Thoroughly mix and sub-sample graintaken from lorries at intakeGrain 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 samplingThe probability of achieving the mean result increaseswith the number of samples taken.Number of samples0Percentage probability of achieving mean result 2 4 6 81009080706050Hagberg Falling NumberSpecific weightMoisture contentProteinVariation 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 samplerSource: HGCA Project Report 3398 HGCA Grain sampling guideSampling 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 scoreSample 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 informationon mycotoxins risk, seewww.hgca.com/mycotoxinsThe HGCA safe storage time calculator will help toidentify grain in most urgent need of attention.www.hgca.com/grainstorage9Sampling at harvest1. 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 storebay, 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 dryeror 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 store6. 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. Thisenables 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 HGCA Grain sampling guideSampling 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 7.58% 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 15C and nonecan breed below 10C. 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 HGCA 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 HGCA's Grainstorage guide for cereals and oilseedswww.hgca.com/grainstorageMycotoxinsIf 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 GerminationMost 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 35apertures). Such sampling is less likely to be representative ofa given bulk than samples taken as the store is loaded aspear just 1.52.0 metres long cannot reach through deeperbulks/bins.The impact on risk of any particular temperature andmoisture content combination can be assessed usingthe HGCA safe storage time calculator.www.hgca.com/grainstorageSafety 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 store11Sampling and monitoring in storeHow?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 1C 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 510 cm below (approximately 45 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 HGCA Grain storageguide or the poster: Insects and mites in stored grainand grain stores. www.hgca.com/grainstorageIt 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 beetleOryzaephilussurinamensisOnly develops ondamaged surfaceof grain. Very active andeasy to trap.Rust-red grain beetleCryptolestesferrugineusPenetrates grainthrough minutecracks. Can fly in hot UKsummers.Grain weevilSitophilusgranariusDevelops insidethe grain. Causes heating.Difficult to find.Common primary insect pests24 HGCA Grain storage guide for cereals and oilseedsPest identification25Pest identificationCan increase rapidly and damage grain stored at temperatures above 15C.Cosmopolitan food miteLepidoglyphusdestructorSurface 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 mitesNormally 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 mothEndrosissarcitrellaSlow todevelop in oldgrain or feedresidues.Moth larvaDistinguishedfrom beetlelarvae by darkhead capsule.Brownhouse mothHofmannophilapseudospretellaOftenassociatedwith animalfeeds.MothsLesser grain borerRhyzoperthadominicaEggs 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 pestsOccasionally found on UK grain but require high temperatures and do notoverwinter well.Foreign grain beetleAhasverus advenaIncreasinglycommon inUK. Very mobileand a commoncause ofrejection.Fungus beetleseg CryptophagusspeciesFrequent 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 furNumbers cantake years tobuild up. Cansurvive longperiods in aninactive form.Plaster beetleLathridiidaeVery small blackbeetles whichflourish in damp,mouldy residues.Australian spider beetlePtinus tectusSeldom found inUK grain,but survives instructure ofwarmer stores.Secondary insect pestsCannot 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 HGCA Grain sampling guideSampling 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 numberSample 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 lorriesHGCA Oilseed Sellers ChecklistThis guide provides a checklist to assist oilseed sellers to maximisemarket opportunities and to avoid the most common contractualproblems, which frequently lead to price claims and disputes.PublishedSpring 2013Grow for a market. There isnow a range of markets in both thefood and non-food sectors. Thecontract type may affect the valueand movement requirements. Thereare also a number of different typesof oilseed rape required in the UK,eg double low, high oleic/lowlinolenic and high erucic, which mayhave an impact on the movementperiod and delivery destination. If aseller is growing different types ofoilseed, the identity of each typemust be preserved and any mixing orcross-contamination avoided. Eachtype has a different end use andrequires pure rapeseed of thecontracted type.Testing for cross-contamination takesplace after delivery and processing,so if a problem is identified it is likelythat a considerable tonnage mayhave been affected, with significantcosts. 'Volunteer' plants can persistfor many years. The variety listed onthe Grain Passport can be verified.Knowingly providing false informationmay lead to substantial priceadjustment claims.Decide on a markettonnage or area contract.Some contracts are available for agiven crop area rather than risking acommitment to a fixed quantity. Inthis case the field OS number(s)should be specified, otherwise aseller will be contractually liable to aminimum tonnage even if the cropfails or the quantity is greatlyreduced.Protect yourself againstprice swings. Oilseeds prices arevolatile and sellers might considerusing marketing pools or tradingperiodically, or to a plan, to minimisemarket risk. Options can provide ameans of insurance against marketvolatility.Knowwhat the buyer wants.Moisture, admixture and oil contentare the key components ofcontractual requirements. The FOSFA26a contract specification is clearand unequivocal: providing the seedfalls within the contractualspecifications on delivery, it will beaccepted without reference to theseller.From harvest 2013, the crop musthave been produced from a varietywhich contains no more than 18mol(micromoles) of glucosinolates. Lowlevels can be ensured by sowingseeds from certified seeds or, foropen-pollinated varieties, from firstgeneration farm-saved seed. Thisencourages rapemeal use in animalfeed rations. For hybrid varieties it isillegal to save seed. Check whether supplyingassured rapeseed is acontractual requirement. If thebuyer plans to resell the product, arethey part of an appropriate assurancescheme? Most end users acceptonly assured crops and assurancemembership numbers are checked atintake.Keep a sealed,representative sample of eachload taken, labelled with lorry details(this may be required for qualityassurance schemes). NB: thesesamples will not be contractual forthe purposes of the determination ofquality or condition at the deliverypoint but they may help if problemsarise.Check lorries for cleanlinessprior to signing the grain passport.Ensure contaminants, such as clayand bituminous products aren'taccidentally loaded with the seed -for example by scooping upfragments of tar with the grainbucket. Get a receipt for every loadyou despatch. It should show thenature of the goods loaded, theapproximate weight, the vehicleregistration number and trailernumber, the name of the haulagecompany, the date and time and thecontract number. In addition, thedriver should print their name clearlyand sign.If a claim/rejection arises:as the seller, you may dispute thefirst analysis results and claim theright to request a retest within twomonths of the delivery date. The costof the independent analysis is to beborne by the buyer, providing thatthe retest result varies from theoriginal by more than 0.8% in oil ormoisture content and 0.2% inadmixture. If the retest result variesby this figure or less, the cost is tobe borne by the party requesting theanalysis. Regardless of who pays,the retest result is final and is whatyou are ultimately paid on. Obtainingthe results of the retest can take aconsiderable time and they arebinding on both parties.If growing for a fuel orenergy market: ensure that thecrop and the land on which it hasbeen grown meet the requirementsof the Renewable Energy DirectiveSustainability Criteria (RED), oftencovered by UK farm assurancestandards. Consult your customer forrequirements.The FOSFA 26a contract sets out the rights and obligations of buyers and sellers. This checklist aims tohelp sellers avoid some of the most common problems. Buyers are obliged to make available the termsand conditions on which the contract is made. Additionally, NFU and NFUS members can view theFOSFA 26a contract at www.nfuonline.com or www.nfus.org.uk 123456798HGCA Cereal Sellers ChecklistThis guide presents a checklist to help cereal sellers avoid themost common problems associated with cereals sales contracts.PublishedAutumn 2012Grow for a market.The first step is to know exactlywhat quality and variety you intendto sell and deliver. Post-harvest,sampling and testing is key toknowing what you have to sell. Donot sell what you cannot deliver. Ifthe quality delivered matches thequality sold, problems will not arise.Consider asking for special clausesto be inserted to suit your ownsituation (see over) and have themstated in the confirmation note. Alsoconsider the likely receivers terms.Remember, prior to agreement, all isnegotiable but after the deal hasbeen struck, terms can only bealtered with the agreement of bothparties.Check the price offeredor calculation method.When will you be paid? Can younegotiate pre-payment or earlypayment? What are the penalties forsub-standard delivery? The risk ofrejection is best tackled by agreeingdiscount scales before the contractis concluded (for fallbacks, see over).Be aware, especially if selling pre-harvest, of the potential replacementcosts you may be called upon tomeet under the contract. Are thereany special terms and conditionsproposed by the buyer?Check the delivery terms.Is there provision for extension? Canyou agree new payment terms if thisapplies? Specify a clear deliveryperiod. Under the AIC contract terms,delivery/collection is at buyers call;therefore, are there any days duringthe period of delivery on which youare unable to move grain? Agreethese before making the contract.Discuss the possibledestinations for your grainwith your buyer beforemaking the deal. If you wish toavoid any specific destinations orexcessive distances, you shoulddiscuss this before the contract isagreed. Bear in mind that the priceobtained will reflect the level of riskaccepted. Any destinations excluded,or special terms, should then bespecified on the confirmation.Remember, different final receivershave different charges and deliveryterms (see contract notes overleaf).Ensure that you and yourbuyer have all possiblecontact numbers and nominate aspecific person to deal withproblems in your absence. Ensureyou receive the written confirmationpromptly, and then check that all ofthe terms (price, quality, variety,quantity, delivery period, paymentterms and any special conditions) areas agreed. If they are not; tell thebuyer immediately, otherwise yoursilence will be taken as acceptance.Obtain an amended confirmationbefore parting with any goods.Check whether supplyingassured grain is a contractualrequirement. If your buyer plansto resell the grain, are they part of anappropriate assurance scheme? Also,grain in store must be kept in conditionaccording to food safety requirementsand sellers contractual obligations.Keep a sealed,representative sample of eachload taken, labelled with lorry details(this may be required for qualityassurance schemes). N.B. thesesamples will not be contractual forthe purposes of the determination ofquality or condition at the deliverypoint, but they may help if problemsarise. Further information is availablein the HGCAs Grain sampling afarmers guide.Check lorries forcleanliness prior to signing thegrain passport. Get a receipt forevery load you despatch. It shouldshow the nature of the goods loaded,the approximate weight, the vehicleregistration number, trailer number,the name of the haulage company,the date, the time and the contractnumber. In addition, the driver shouldprint their name clearly and sign.You may insist on beingnotified of any claims before a loadis tipped unless there is a fall-backprovision. Claims should be notifiedas soon as possible and writtenconfirmation posted within twobusiness days of the goods arrivingat their ultimate UK destination. Ifthey are not, the buyer will not havecomplied with the terms of thecontract and you will not have toaccept them unless the contractalready has a sliding scale of price(fallbacks, see over) against qualityon delivery.If a claim/rejection isnotified and you dispute it, youhave the right to request that asealed sample is sent forindependent testing by an agreedanalyst. Also ensure you have thecontractual right to be representedwhen that sample is taken. The costsof independent sampling andanalysis are for the grower if theclaim/rejection is upheld.The AIC No.1 Contract sets out the rights and obligations of grain buyers and sellers. This Top Tenchecklist aims to help sellers avoid some of the most common problems. Grain buyers are obliged tomake available the terms and conditions on which the contract is made. Additionally NFU and NFUSmembers can view the AIC No.1 contract at www.nfuonline.com or www.nfus.org.uk12345679810IncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleIncrementalsampleAggregate sampleCombine at least ten 200g samples toproduce an aggregate sample.Mix the aggregate sample and sub-sample to produce therepresentative sample(s) (see page 17).RepresentativesampleRetainSee the HGCA Cereal Sellers' Checklist and HGCAOilseed Sellers' Checklist for more information.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. 13Sampling at outloadingAutomatic 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 HGCA-funded tests, this sampling technique provedeasy to use, did not delay loading and did notcompromise operator safety. The test results of bucketsamples agreed well with samples collected fromlorries at delivery when best practice recommendationswere followed by both the farmer and 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 HGCA Grain sampling guideSampling 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 accessibleAutomatic 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.ntakes15Sampling at commercial intakesMixing and sub-samplingMost automatic sampling equipment produces anaggregate sample of 68 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 visualinspection of grain,see the HGCA poster'Inspecting grain fordefects andimpurities'.See www.hgca.com/graintesting for moreinformation and training tools for grain analysts.Sample storage16 HGCA Grain sampling guideSampling 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 HGCA risk assessment for fusarium mycotoxins in wheatshould be completed Mycotoxins formed before harvest are stable and likely toremain during storage but not increaseLegal 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 G34 and TS121www.hgca.com/mycotoxinsFor more information ongrain storage, seeHGCA's Grain storage guide forcereals and oilseedswww.hgca.com/grainstorageMycotoxin testingMixing and sub-sampling17Sampling and mycotoxins / Mixing and sub-samplingA 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).3. Mix samples A and D again toform a new cone of grain.ACDB ACDBADB + CA+D Mixing grain18 HGCA Grain sampling guideFurther informationGrain storageG52 HGCA Grain storage guide for cereals and oilseeds,3rdedition (2011)G56 Rodent control in agriculture an HGCA guide, 2ndedition (2012)G37 Grain moisture guidelines for measurement(2008)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 mycotoxinsG34 Guidelines to minimise risk of fusariummycotoxins in cereals (2010)TS121 HGCA risk assessment for fusarium mycotoxins inwheat (2013)Sellers' ChecklistsCSC2012 HGCA Cereal Sellers' Checklist (2012)OSC2013 HGCA Oilseed Sellers' Checklist (2013)HGCA Project ReportsPR515 Investigation into the specific weight differencesbetween wheat varieties tested in the HGCARecommended List and commercially-growncrops from 20072012 (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)HGCA Research ReviewsRR50 Grain sampling methods to achieve consumerconfidence and food safety (2003)HGCA publications and details of HGCA-funded projects are all available on the HGCA website www.hgca.comHGCA information19Further 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.ukWebsitesAgricultural Industries Confederation (AIC):www.agindustries.org.ukBSI Standards: http://shop.bsigroup.comFederation of Oils, Seeds and Fats Associations (FOSFA):www.fosfa.orgGrain and Feed Trade Association (GAFTA):www.gafta.comHGCA: www.hgca.comMaltsters' Association of Great Britain (MAGB):www.ukmalt.comNational Association of British and Irish Millers (nabim):www.nabim.org.ukNFU: www.nfuonline.comRed Tractor Farm Assurance:www.assurance.redtractor.org.ukScottish Quality Cereals (SQC): www.sfqc.co.ukBritish and International Standards BS EN ISO 24333:2009 Cereals and cereal products samplingThis 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, 13kg 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 samplingCommission 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.HGCAStoneleigh ParkWarwickshire CV8 2TLwww.hgca.comHGCA PublicationsT 0845 245 0009E hgca@cambertown.comDisclaimerWhile the Agriculture and Horticulture Development Board, operating through its HGCA division, seeks to ensure that the information contained within thisdocument is accurate at the time of printing, no warranty is given in respect thereof and, to the maximum extent permitted by law, the Agriculture andHorticulture Development 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 as unprotected andthus free for general use. No endorsement of named products is intended, nor is any criticism implied of other alternative, but unnamed products.HGCA is the cereals and oilseeds division of the Agriculture and Horticulture Development Board.AcknowledgementsThis guide, funded by HGCA, was written by Dr Ken Wildey,Technology for Growth, and Geoff Dodgson, Ware AnthonyRust.HGCA 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, HGCA; 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, HGCA Board/Committee members.Photographs of automatic bucket sampler (page 13) courtesy ofClaydon Yield-O-Meter Ltd.Edited by Dr Emily Boys, HGCA.Autumn 2013Electronic version can be downloaded at www.hgca.comPrinted copies available on request: publications@hgca.ahdb.org.uk Agriculture and Horticulture Development Board 2013 All rights reservedHGCA guide 60 (G60)