農(nóng)業(yè)植物病害IPM（英文）

Integrateddiseasemanagement

DiseaseThediseasetrianglehostpathogenenvironmentThediseasepyramidgrowerpathogenenvironmenthostDisease

Thepartonintegrateddiseasemanagementinthiscourseconsistsof9lectures1.1,1.2,,,,,1.9pathogenenvironmenthost1.1

IntroductiontointegrateddiseasemanagementDiseasegrowerpathogenenvironmenthost1.2

BasicsofplantdiseaseepidemiologyandmodelingDiseasegrowerpathogenenvironmenthost1.3Assessmentofdiseaseintensity

DiseasegrowerpathogenenvironmenthostDisease1.4AssessmentofyieldlossesimposedbyplantpathogensgrowerpathogenenvironmenthostDisease1.5Predictionofdiseaseoutbreaks

growerpathogenenvironmenthostDisease1.6RationaldiseasemanagementinintensiveandinextensivecropsgrowerpathogenenvironmenthostDisease1.7Decisionsupportsystems

grower30-50%oftheyield,world-wide,islostduetopestanddiseaseattack.Leaf-minerdamageontomatoleafScarbbeetlegrubdamagetopeanut’sshellsInsevereepidemics,lossesmayreach80-100%oftheattainableyield!PotatoplotdevastatedbyPhytophthorainfestans,thecausalagentoflateblight

PlottreatedwithfungicidesPlottreatedwithfungicidesTopreventthelosses,growershavetomanagethepestsandthedisease.InthiscoursewediscussthevariousmeasuresusedforpestanddiseasecontrolanddealwiththeirintegrationTheterm“integratedPestManagement”(IPM)wasusedinthefirsttimein1952bytheentomologistsMichelbacher&Bacon.In1966,Smith&ReynoldsdefinedIPMas:IntegratedPestManagement“anapproachforpestmanagement

that

integratescontrolmeasures

inorder

tosuppressthepestpopulationbelowtheeconomiclevel”

Inthe1960’sand1970’sthegoalofIPMwastooptimizepesticideusetolowerthecostofpestmanagement,andtoreducetheriskfordevelopmentofpestpopulationsresistanttothepesticides.Inthe1980’sand1990’sthegoalofIPMwastoreducethecontaminationoftheagriculturalproductswithpesticideresidues,andtoprotecttheenvironmentandtheusers.DecisionsupportsystemsMonitoringActionthresholdsculturalbiologicalIPMIntegrationofcontrolmeasuresRationaluseofthecontrolmeasureschemicalinducedresistancegeneticResistancemanagementPlantlifecycleSeedgerminationSeedlingestablishmentVegetativegrowthreproductivegrowthSeedformationSeeddisseminationsurvivalPathogenlifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationsurvivalPlantandpathogenlifecyclesseedgerminationseedlingestablishmentvegetativegrowthreproductivegrowthseedformationseeddisseminationsurvivalepidemicMonocyclicpathogensCompleteonlyonediseasecycleinagrowingseason(100-y)QRdydtQ=amountofinitialinoculumR=infectionefficacyoftheinoculumy=diseaseintensity(%)t=timeTimeDiseaseintensity(%)TimeDiseaseintensity(logit)QRLogit=ln()100100-yFormonocyclicpathogensAlldiseaseplantsareinfectedfrominoculumthatsurvivedfromthepreviousseasonTimeDiseaseintensity(%)PreviousseasoninoculumThehostissusceptibleforaveryshorttine(smuts)Theinfectingstructuresdonotdisseminatewithinthesamegrowingseason(soil-bornepathogens)Theenvironmentalconditionsareconduciveforinfectionforashorttime(scab)ThegrowthofthepathogenisveryslowPathogensaremonocyclicbecause:PolycyclicpathogensCompleteseveraldiseasecyclesinagrowingseasonrydydt(100-y)r=apparentinfectionratey=diseaseintensity(%)t=timeTimeDiseaseintensity(logit)rLogit=ln()y100-yTimeDiseaseintensity(%)ForpolycyclicpathogensTimeDiseaseintensity(%)FewplantsareinfectedfrominoculumthatsurvivedfromthepreviousseasonPreviousseasoninoculumcurrentseasoninoculumMostplantsareinfectedfrominoculumthatwasproliferatedwithinthecurrentseasonThediseasetrianglehostpathogenenvironmentThediseasepyramidgrowerpathogenenvironmenthostControlmeasures“Strategicmeans”:

Meansthatareappliedonce,andtheireffectisapparentforalongtime(theentiregrowingseason)

“Tacticalmeasures”:

Meansthatareappliedfrequently,andareeffectiveforarelativelyshorttimeChemical CulturalBiological GeneticInducedresistanceTheeffectsofcontrolmeasuresondiseasedevelopmentDependson

thebiologyofthepathogen

(monocyclicorpolycyclic)

andon

thecharacteristicsofthemeasure

(strategicortactical)MonocyclicpathogensCompleteonlyonediseasecycleinagrowingseason(100-y)QRdydtQ=amountofinitialinoculumR=infectionefficacyoftheinoculumy=diseaseintensity(%)t=timePolycyclicpathogensrydydt(100-y)r=apparentinfectionratey=diseaseintensity(%)t=timeCompleteseveraldiseasecyclesinagrowingseasonTimeDiseaseintensity(logit)TimeDiseaseintensity(%)PolycyclicpathogensTimeDiseaseintensity(%)MonocyclicpathogensInitialdiseaserateTimeDiseaseintensity(logit)PossibleeffectsofcontrolmeasuresondiseaseprogressEffectsontheamountofinitialdiseaseSoiltreatment

Seedtreatment

SystemicfungicidesCroprotation

Certifiedseeds

Sanitation

Escape(plantingtime)

BiocontrolagentsTimeDiseaseintensity(logit)PossibleeffectsofcontrolmeasuresondiseaseprogressInmonocyclicpathogens:

ontheinfectionefficacyoftheinoculumPolycyclicpathogens:

EffectsontheapparentinfectionrateProtectantfungicides

SystemicfungicidesGenotyperesistance

culturalmeasures(e.g.,heating,ventilation)

BiocontrolmeasuresOntherateofdiseasedevelopmentTimeDiseaseintensity(logit)PossibleeffectsofcontrolmeasuresondiseaseprogressOntherateofdiseasedevelopmentEffectsontheamountofinitialinoculumandSystemicfungicidesIntegrationofcontrolmeasuresDepositionandtranslocationofcontrolmeasuresWithintreatedleavesWithintreatedplantsDepositionandtranslocationofcontrolmeasureswithintreatedleavesMesostemicmeasureTrans-laminarmeasureDepositionandtranslocationofcontrolmeasureswithintreatedleavesProtectantmeasureSystemicmeasureMeasureswith

re-distributionabilityDepositionandtranslocationofcontrolmeasureswithintreatedleavesApplicationofasystemicmeasuretotherootsystemDepositionandtranslocationofcontrolmeasureswithintreatedplantsApplicationofasystemicmeasuretothestemDepositionandtranslocationofcontrolmeasureswithintreatedplantsApplicationofasystemicmeasuretoaleafDepositionandtranslocationofcontrolmeasureswithintreatedplantsApplicationofasystemicmeasuretothefoliageofagrowingplantDepositionandtranslocationofcontrolmeasureswithintreatedplantsNecroticareainfectedareainvadedareaCanthecontrolmeasurereachitstarget?BiotrophicpathogensNectotrophicpathogensIntegrationofcontrolmeasuresTimeCombinedapplicationApplicationaccordingtotheexpectedefficacyofeachmeasureAlternatedapplicationCombinedefficacyofcontrolmeasuresControlefficacy(%)11+22exp.Additive1+2obs.1+2Synergisticobs.1+2Antagonisticobs.Calculationofcombinedefficacyofcontrolmeasures-Step1Controlefficacy(%)121+2obs.A=controlefficacyof#1B=controlefficacyof#2A+B(obs.)=observedcontrol efficacyof1+2AbbottformulaE(exp)=A+B-(A*B)/1001+2exp.A+B(exp.)=expectedcontrol efficacyof1+2SF=E(obs)/E(expControlefficacy(%)1+21+2exp.obs.SF=SynergyfactorE(obs.)=Observedcontrol efficacyof1+2E(exp.)=Expectedcontrol efficacyof1+2Calculationofcombinedefficacyofcontrolmeasures-Step2CombinedefficacyofcontrolmeasuresControlefficacy(%)1+21+2exp.obs.SF=1additiveControlefficacy(%)1+21+2exp.obs.SF>1synergisticSF=SynergyfactorControlefficacy(%)1+21+2exp.obs.SF<1antagonisticCombinedefficacyofcontrolmeasuresTreatmentDisease severity(%)121+2Control20301580AbbottformulaE(exp)=A+B-(A*B)/100E(exp)=75+62.5-(75*62.5)/100=90.6%controlefficacyof#1=100-(20/80)*100=75%controlefficacyof#2=

100-(30/80)*100=62.5%controlefficacyof1+2=

100-(15/80)*100=85%E=100-(t/c)*100CombinedefficacyofcontrolmeasuresSF=E(obs)/E(expE(obs.)=Observedcontrol efficacyof1+2E(exp.)=Expectedcontrol efficacyof1+2E(obs.)=85%

E(exp.)=90.6%SF=85/90.6=0.93SF<1antagonisticreactionWhentoapplya“tactical”controlmeasure?

EffectsoftheenvironmentonthepathogenEffectsofthecontrolmeasureonthepathogen’slifecycleEffectsofthehostonthepathogengrowerpathogenenvironmenthostWhentotreat?EffectsoftheenvironmentonthepathogensporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationWhentotreat?EffectsoftheenvironmentonthepathogenWhentotreat?EffectsoftheenvironmentonthepathogenEnvironmentalfactorTimeDiseaseintensity(%)RainPeriodsofhighrelativehumidityHighorlowtemperaturesHailSandstormsEnvironmentalfactorsWhentotreat?EffectsoftheenvironmentonthepathogensporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationTimeDiseaseseverity(%)Whentoapplya“tactical”controlmeasure?

EffectsoftheenvironmentonthepathogenEffectsofthecontrolmeasureonthepathogen’slifecycleEffectsofthehostonthepathogencontrolmeasurepathogenenvironmenthostWhentotreat?EffectsofthecontrolmeasureonthepathogenWhentotreat?Effectsofcontrolmeasuresonthepathogen’slifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationProtectantfungicides,biocontrolagent,heating,ventilationsporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationMesostemicfungicides,biocontrolagents,genotyperesistanceWhentotreat?Effectsofcontrolmeasuresonthepathogen’slifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationSystemicfungicides,biocontrolagentsWhentospray?Effectsoffungicidesinthepathogen’slifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationCurativefungicides,heating,ventilating,lightfiltersWhentotreat?Effectsofcontrolmeasuresonthepathogen’slifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationEradicativefungicides,biocontrolagents,ventilation,heatingWhentotreat?Effectsofcontrolmeasuresonthepathogen’slifecycleWhentoapplya“tactical”controlmeasure?

EffectsoftheenvironmentonthepathogenEffectsofthecontrolmeasureonthepathogenEffectsofthehostonthepathogenWhentotreat?Effectsofthehost:age-relatedresistanceTimeHostresistanceTimeDiseaseintensity(%)growerpathogenenvironmenthostConcludingremarksApplicationofcontrolmeasuresshouldbebasedon:Thebiologyofthepathogen(monocyclic,polycyclic)Thepossibleactivityofthecontrolmeasure(protectant,mesostemic,translaminar,systemic)Therelationshipsbetweenthehost,thepathogenandtheenvironment:

effectsoftheenvironmentonthepathogen

effectsofthecontrolmeasuresonthepathogen

effectsofthehostonthepathogenEpidemiology:

thesciencethatdealswiththedynamicrelationshipsbetweenhostsandtheirpathogensatthepopulationlevelDiseaseprogresscurve:

aplotthatshowsgraphicallyhowdiseaseintensitychangesovertimeTimeDiseaseintensityEpidemic:

a

change

indiseaseintensity

overtimedydtHowdiseaseintensityismeasured?Diseaseincidence:

Theproportionofinfectedhostunits,outofthetotalunitssampledDiseaseseverity:

Theproportionofinfectedpart(orarea),ineachofthesampledunits4/10*100=40%inpercent(60+10+30+1)/10*100=10.1%6010301000000inpercent,cm2,number,index...PlantlifecycleSeedgerminationSeedlingestablishmentVegetativegrowthreproductivegrowthSeedformationSeeddisseminationPlantandpathogenlifecyclesseedgerminationseedlingestablishmentvegetativegrowthreproductivegrowthseedformationseeddisseminationsurvivalepidemicMonocyclicpathogensCompleteonlyonediseasecycleinagrowingseasonThehostissusceptibleforaveryshorttine(smuts)Theinfectionunitsdonotdisseminatewithinthesamegrowingseason(soil-bornepathogens)TheenvironmentalconditionsareconduciveforashorttimeThegrowthofthepathogenisslowPathogensaremonocyclicbecause:MonocyclicpathogensCompleteonlyonediseasecycleinagrowingseason(100-y)QRdydtQ=amountofinitialinoculumR=infectionefficacyoftheinoculumy=diseaseseverityTimeDiseaseseverity(%)TimeDiseaseseverity(logit)QRLogit=ln()100100-yPolycyclicpathogensCompleteseveraldiseasecyclesinagrowingseasonrydydt(100-y)r=apparentinfectionratey=diseaseseverityTimeDiseaseseverity(logit)rLogit=ln()y100-yTimeDiseaseseverity(%)ThediseasetrianglehostpathogenenvironmenthostpathogenenvironmentrainThediseasetrianglehostpathogenenvironmentrain

changeinsensitivityThediseasetrianglehostpathogenenvironmentAge-relatedresistanceThediseasetrianglehostpathogenenvironmentexcessivegrowthleafwetnessThediseasetrianglehostpathogenenvironmentThediseasetriangleEffectsoftheenvironmentonthepathogenEffectsoftheenvironmentonthepathogen’slifecyclesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationTimeDiseaseseverity(%)EffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationsporegermtubeapresoriaEffectsofenvironmentalfactorssporegerminationlesionformationreproductivegrowthsporedisseminationestablishmentgermination(%)Temperature(oC)optimalDurationofwetness(hours)germination(%)Relativehumidity(%)germination(%)EffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationLatentperiodEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationLatentperiodLatentperiod(days)Temperature(oC)optimalEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationopeningsporesoutinEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationRelativehumidity(%)No.ofsporesNo.ofsporesTemperature(oC)optimalWetnessduration(hrs)No.ofsporesInductionoflightsporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationTime(weeks)012345Diseasecycle

InfectiousperiodEffectsofenvironmentalfactorsInfectiousperiodTimeNo.ofsporesEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationWindEffectsofenvironmentalfactorssporegerminationestablishmentreproductivegrowthsporedisseminationsporeformationInfectedcarrotfieldEastNo.ofspores12:00noon24:00night24:00nightWinddirectionday-timeWestNo.ofspores12:00noon24:00night24:00nightWinddirectionmorningandeveningEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationRainsplashWindEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationsporeformationSeed/

plantdebrisInsectsWaterRainsplashWindEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporedisseminationShort-termsurvivalsporeformationRelativehumidity(%)SurvivalSolarradiationSurvivalTemperature(oC)SurvivalEffectsofenvironmentalfactorssporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationTemperature(oC)Durationofwetness(hrs)CompensationNodiseaseMod.diseaseSeveredisease0204060Discoloration(%,Z)0204060801005152535Wetness(%,W)Temperature(oC,T)Z=-37.48+6.21T-0.29T2+0.004T3+0.53W-0.002W2+0.006WTp<0.0001;R2=0.774InfluenceofwetnessandtemperatureoncottondiscolorationInfluenceofwetnessandtemperatureonfireblightinfectionWetnessduration(hrs)04812160816243200.20.40.60.81.0Temperature(hrs)InfectionprobabilityThediseasetrianglehostpathogenenvironmentEffectsofthehostonthepathogenMonogenicresistancesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationTimeDiseaseseverity(%)resistantsusceptiblePolygenicresistancesporegerminationestablishmentlesionformationreproductivegrowthsporeformationsporedisseminationinfectionefficacyinfectiousperiodlatentperiodReducedsporulationTimeDiseaseseverity(%)resistantsusceptibleAge-relatedresistanceTimeDiseaseseverity(%)TimeHostresistanceTimeDiseaseseverity(%)TimeHostresistanceMonogenicorpolygenicresistanceTimeDiseaseseverity(%)TimeDiseaseseverity(%)DiseasedevelopmentintimeTimeDiseaseseverity(%)TimeDiseaseseverity(%)TimeDiseaseseverity(%)TimeDiseaseseverity(%)Diseasedevelopmentinspace1.Short-distancedispersalDistanceNo.ofsporesDiseasedevelopmentinspace2.Long-distancedispersalDistanceNo.ofsporesDiseasedevelopmentinspace3.Long-distancedispersalinwaterDistanceNo.ofsporesriverDiseasedevelopmentinspace4.Within-rowdispersalWhydoweneed(want)toassessdiseaseintensity?

or

WhataretheusesofdiseaseintensityrecordsFormakingdecisionconcerningdiseasemanagementForquantifyingtheeffectofthepathogensonthehostplantandonyieldFordeterminingtheefficacyofvariouscontrolmeasures(pesticides,genotyperesistance,agronomicmeasures,etc.)ForverifyingthequalityofagronomicproductsandseedMethodstoassessdiseaseintensityDiseaseincidence:Theproportionofinfectedhostunits,outofthetotalunitssampled4/10*100=40%4/10*100=40%MethodstoassessdiseaseintensityDiseaseseverity:Theproportionofinfectedpart(ortheinfectedarea),ineachofthesampledunits(60+10+30+1)/10*100=10.1%6010301000000Percentagescale(0-100%)4221000000(4+2+2+1)/10*100=0.9Indexscale(0-4)Whatisbetter:

toassessdiseaseincidence

or

toassessdiseaseseverity?Whatiseasier?Whatislesssubjectivetoerrors?Whatrepresentsbettertheeffect ofthepathogenonthehost?Candiseaseincidencerecordsbeconvertedtodiseaseseverity?100Diseaseincidence(%)0Diseaseseverity(%)01005050Diseaseincidence(%)0100Diseaseseverity(%)010505Whatscaletouseintheassessments?Numberofinfectedblossomsinablossom-clusterNumberofinfectedblossomsinablossom-cluster,outofthetotalnumberofblossomsinthatclusterNumberofinfectedblossom-clustersinatreeNumberofinfectedblossom-clustersinatree,outofthetotalnumberofblossom-clustersinthattreeSamplingunit:atreeSamplingunit:blossom-clusterThenumberoftreeswithinfectedblossom-clustersNumberoftreeswithinfectedblossom-clusters

outofthenumberoftreesintheorchardSamplingunit:anorchardWhichpartoftheplantshouldbeassessed?FlagleafLeaf-1Leaf-3Leaf-5Leaf-2Leaf-4SeptorialeafblotchcausedbyMycosphaerellagraminicolaWhichtypeofsymptomshouldbeassessed?FruitrotFruitghostspotsGreymouldcausedbyBotrytiscinereaLeafinfectionSteminfectionHowtoassessdiseaseseverity?TheWebber-Fechnerlow:1.Theeyecandetectlogarithmdifferences

1%3%

40%43%Howtoassessdiseaseseverity?TheWebber-Fechnerlow:2.Upto50%severity-theeyedetectthediseased,outofthehealthyportion

above50%severity-theeyedetectthehealthy,outofthediseasedportion

3%12%

88%97%ScalesforassessmentofdiseaseseverityTheHorsfallandBarrattscale1)0%2)1-2%3)2-6%4)6-12%5)12-25%6)25-50%12)100%11)98-99%10)94-98%9)88-94%8)75-88%7)50-75%Pictorialscale(%diseasedarea)0%1%2%5%10%20%50%80%90%95%ScalesforassessmentofdiseaseseverityDescriptiveverbalscale(%)0% Lateblightisnotseeninthefield0.5% Uptoonelesionper100m21% Upto5lesionsperplant5% Oneoutof10leafletsisinfected25% Almostallleafletsareinfected.Thefieldstilllooksgreen,but withmanyinfectedfoci.50% Halfofthefoliageisinfected.Thefieldlooksinfected.75% Mostofthefoliageisdiseased.Thefieldlooksdefoliatedwith somegreenpoints.95% Leavesweredefoliated.Someofthestemsarestillgreen.ScalesforassessmentofdiseaseseverityDescriptiveindexesNumberoflesionsperleaf0=nolesions1=1-10lesions2=10-20lesions3=20-50lesions4=>50lesionsIndex040=Healthy1=Lowdiseaseseverity2=Moderatediseaseseverity3=Highdiseaseseverity4=DeadplantScalesforassessmentofdiseaseseverityDescriptiveindexesNumberoflesionsperleaf0=nolesions5=1-10lesions15=10-20lesions40=30-50lesions60=50-70lesions85=70-100lesionsScalesforassessmentofdiseaseseverityNumberoflesionsperleaf0=nolesions1=1-10lesions2=10-20lesions3=30-50lesions4=50-70lesions5=70-100lesionsDescriptiveindex-sporulationofBotrytiscinereaontomatostempieces12345ScalesforassessmentofdiseaseseverityMethodsforanalyzingdiseaserecords-DescriptivestatisticsSample:5,100,2,3,6,5,5,5,6,4Frequentrecord:themostfrequentrecordinthesample5.0Mean:sumofthevaluesdividedbythenumberofrecords14.1Mid-range:meanofthetwoextremevalues51.0Median:thevaluethatsplitthedistributionoftherecords5.0Nominalvariable

identificationoftherecordsMethodsforanalyzingdiseaserecords-Variabletypesnumbersontheshirtsoffootballplayers(1,2,7,12)6schoolgrade(gradeA,B,C….F)Methodsforanalyzingdiseaserecords-VariabletypesOrdinalvariableidentificationoftherecordstheorderoftherecordsMethodsforanalyzingdiseaserecords-Variabletypesweight,length….20kg5kg5kg5kg5kgContinuousvariableidentificationoftherecordstheorderoftherecordstheratiobetweenrecordsMethodsforanalyzingdiseaserecordsStatisticsandvariabletypesVariable

typestatisticsFrequentmid-rangemedianmeannumbercontinuousnominalordinalMethodsforanalyzingdiseaserecordsStatisticsandvariabletypesTheoutcomeisthatcalculationofmeansandconductinganalysisofvariance(ANOVA)testsmaybedoneonlyfordiseaserecordsthatarecontinuousvariablesTheHorsfallandBarrattscaleTypeofvariable:

ordinalMostfrequentno.Mid-rangeMedianMean1)0%2)1-2%3)2-6%4)6-12%5)12-25%6)25-50%12)100%11)98-99%10)94-98%9)88-94%8)75-88%7)50-75%Pictorialscale0%1%2%5%10%20%50%80%90%95%Typeofvariable:

continuousMostfrequentno.Mid-rangeMedianMeanDescriptiveverbalscale0% Lateblightisnotseeninthefield0.5% Fewinfectedplants.Uptoonelesionper100sq.meters1% Upto5lesionsperplant5% Oneoutof10leafletsisinfected25% Almostallleafletsareinfected.Thefieldstilllooksgreen,but withmanyinfectedfoci.50% Halfofthefoliageisinfected.Thefieldlooksinfected.75% Mostofthefoliageisdiseased.Thefieldlooksdefoliatedwith somegreenpoints.95% Leavesweredefoliated.Someofthestemsarestillgreen.Typeofvariable:

continuousMostfrequentno.Mid-rangeMedianMeanTypeofvariable:

ordinalMostfrequentno.Mid-rangeMedianMeanNumberoflesionsperleaf0=nolesions1=1-10lesions2=10-20lesions3=20-50lesions4=>50lesionsIndex040=Healthy1=Lowdiseaseseverity2=Moderatediseaseseverity3=Highdiseaseseverity4=DeadplantTypeofvariable:

ordinalMostfrequentno.Mid-rangeMedianMeanNumberoflesionsperleaf0=nolesions1=1-10lesions2=10-20lesions3=30-50lesions4=50-70lesions5=70-100lesionsTypeofvariable:

continuousMostfrequentno.Mid-rangeMedianMeanNumberoflesionsperleaf0=nolesions5=1-10lesions15=10-20lesions40=30-50lesions60=50-70lesions85=70-100lesionsDescriptiveindex-sporulationofBotrytiscinereaontomatosteppieces12345Typeofvariable:

ordinalMostfrequentno.Mid-rangeMedianMeanDescriptiveindex-sporulationofBotrytiscinereaontomatostempieces01234Treatment1:4replicates:1,2,2,1Meanindex=1.5Treatment2:4replicates:3,3,4,4Meanindex=3.50510152001234SporulationindexNo.ofspores(x106)Meannumberofspores:1,500,000Meannumberofspores:10,750,000Fordiseaserecordsthatareordinalvariables,non-parametricstatisticsshouldbeusedTestsforcomparingtwotreatmentsMann-Whitney

WilcoxonSingleRank

SpearmanRankCorrelationCoefficient

Kolmogrov-Smirnov

Wald-WolfowitzRunsTestsforcomparingthree(ormore)treatmentsKrustal-Wallis

FriedmanMethodsforpresentingdiseaserecordsTreatmentDiseaseseverity(%)CultivarA 82.5aCultivarB 64.3bCultivarC 50.3bcCultivarD 25.9cCultivarE 4.1dMethodsforpresentingdiseaserecordsTime(days)Diseaseseverity(%)=SETime(days)Diseaseseverity(%)=LSDLSD=LeastSignificantDifferenceSE=standarderrorTherearealsoproblems!60%?Measurementofhealthyleafareadigitalanalyzersvideocamerameasurementofphotos60%Totalleafarea=125cm2healthyleafarea=98cm2diseasedleafarea=27cm2MeasurementofradiationDisease