C t l O ti f RiC t l O ti f RiControl Options for Rice Control Options for Rice Bacterial Panicle BlightBacterial Panicle BlightBacterial Panicle BlightBacterial Panicle BlightGroth D EGroth D E 11 Rush M CRush M C 22 Shahjahan A K MShahjahan A K M 22Groth, D.E.Groth, D.E. , Rush, M.C., Rush, M.C. , Shahjahan, A.K.M., Shahjahan, A.K.M. , ,

Sha, X.Sha, X.11, and Ham, J., and Ham, J. 22

LSU AgCenter, LSU AgCenter, 11Rice Research Station, Rayne, LA and Rice Research Station, Rayne, LA and 22Department of Plant Pathology and Crop Physiology, Baton Department of Plant Pathology and Crop Physiology, Baton

Ro ge LA USARo ge LA USARouge, LA USARouge, LA USA

Major Rice Diseases Major Rice Diseases

Bacterial Panicle BlightBacterial Panicle Blight

Areas of researchAreas of researchAreas of researchAreas of research

EtiologyEtiologyEtiologyEtiologyEpidemiologyEpidemiologyC lt l tC lt l tCultural managementCultural managementFoliar pesticidesFoliar pesticidesSeed treatmentsSeed treatmentsDisease resistanceDisease resistanceDisease resistanceDisease resistance

EtiologyEtiologyEtiologyEtiology

Isolation by plant inoculationIsolation by plant inoculationIsolation by plant inoculationIsolation by plant inoculationBacterial species as determined by BioLogBacterial species as determined by BioLogBurkholderia glumaeBurkholderia glumae most prevalentmost prevalentBurkholderia glumaeBurkholderia glumae most prevalentmost prevalentOthers identifiedOthers identified

–– B gladioliB gladioliB. gladioliB. gladioli–– B. cepaceaB. cepacea–– B. pyrrpciniaB. pyrrpciniapy ppy pDevelopment of a realDevelopment of a real--time PCR to identify time PCR to identify B. B. glumae glumae andand B. gladioliB. gladioli in green tissues in green tissues

Isolation and identificationIsolation and identificationIsolation and identificationIsolation and identification

EpidemiologyEpidemiologyB. gladioli found surviving in soil but not B. B. gladioli found surviving in soil but not B. glumaeglumaeglumaeglumaeSpread of epiphytic populations limited Spread of epiphytic populations limited during growing seasonduring growing seasonduring growing seasonduring growing season38 and 4038 and 40°°C for optimum for bacteriaC for optimum for bacteria

Cultural managementCultural managementCultural managementCultural management

Nitrogen managementNitrogen managementNitrogen managementNitrogen management–– Higher N rate more diseaseHigher N rate more disease

Planting datePlanting date–– Late planted rice more diseaseLate planted rice more disease

Exposed to higher temperaturesExposed to higher temperatures

Foliar ApplicationsFoliar ApplicationsFoliar ApplicationsFoliar Applications

AntibioticsAntibioticsAntibioticsAntibioticsCoppersCoppersO li i A idO li i A idOxolinic AcidOxolinic AcidMicro nutrient mixturesMicro nutrient mixturesGrowth regulatorsGrowth regulators

Tested Products Tested Products InIn--vitrovitro

Foliar TrialsFoliar TrialsFoliar TrialsFoliar Trials

Applied between boot and headingApplied between boot and headingApplied between boot and headingApplied between boot and headingVarious rates ex. Starner 0.35Various rates ex. Starner 0.35--0.50 lb 0.50 lb aiai/A/AI l t d d i l t d t i lI l t d d i l t d t i lInoculated and uninoculated trialsInoculated and uninoculated trialsCoppers tend to be toxicCoppers tend to be toxicAntibiotics were not very effectiveAntibiotics were not very effectiveOxolinic acid (Starner 20WP) bestOxolinic acid (Starner 20WP) bestOxolinic acid (Starner 20WP) bestOxolinic acid (Starner 20WP) best

Difficulties with foliar applicationsDifficulties with foliar applicationsDifficulties with foliar applicationsDifficulties with foliar applications

No prediction or scouting methodsNo prediction or scouting methodsNo prediction or scouting methodsNo prediction or scouting methodsErratic occurrenceErratic occurrenceR l t blR l t blRegulatory problemsRegulatory problemsCost of preventative spraysCost of preventative spraysToxicity of coppersToxicity of coppersIncreased yields and milling erraticIncreased yields and milling erraticIncreased yields and milling erraticIncreased yields and milling erratic

N h i l t l i th f tN h i l t l i th f tNo chemical control in the near futureNo chemical control in the near future

Scouting and Determining NeedScouting and Determining Need

Damage is most severe during periods of Damage is most severe during periods of unusually hot weather or unusually hot nights. No unusually hot weather or unusually hot nights. No y y gy y gscouting methods are available and no chemical scouting methods are available and no chemical control agents are labeled to control bacterial control agents are labeled to control bacterial panicle blightpanicle blight. .

Seed treatmentsSeed treatmentsSeed treatmentsSeed treatments

Materials testedMaterials testedMaterials testedMaterials tested–– Coppers fungicidesCoppers fungicides

AntibioticsAntibiotics–– AntibioticsAntibiotics–– Oxolinic acidOxolinic acid

D l t f ELISA d PCR t t fD l t f ELISA d PCR t t fDevelopment of ELISA and PCR tests for Development of ELISA and PCR tests for identifying infected seedidentifying infected seed--lots lots Seed treatments erraticSeed treatments erratic

Disease resistanceDisease resistanceDisease resistanceDisease resistance

Screening methodsScreening methodsScreening methodsScreening methods–– Inoculation at boot split and headingInoculation at boot split and heading

Bacterial concentration critical ~1x10Bacterial concentration critical ~1x1088–– Bacterial concentration critical ~1x10Bacterial concentration critical ~1x1088

CFU/mlCFU/ml

–– Too high all susceptibleToo high all susceptible

–– Too low all are resistantToo low all are resistant

–– Isolate must produce toxinIsolate must produce toxin

Inoculation timingInoculation timing -- 2 times2 timesInoculation timing Inoculation timing 2 times2 times

Rating scale (0Rating scale (0--9)9)0 no damage (Immune)0 no damage (Immune)3 203 20--30% damage (moderately resistance)30% damage (moderately resistance)3 203 20 30% damage (moderately resistance)30% damage (moderately resistance)6 506 50--60% damage (susceptible)60% damage (susceptible)9 100% t ilit ( tibl )9 100% t ilit ( tibl )9 100% sterility (very susceptible)9 100% sterility (very susceptible)

2 vs 8

Disease resistance cont.Disease resistance cont.Host resistanceHost resistance–– High levels of resistance found (1High levels of resistance found (1--3 ratings)3 ratings)

Nipponbare, LMNipponbare, LM--1, Jupiter, TeQing, AB647, others1, Jupiter, TeQing, AB647, others–– Crosses made and populations being evaluatedCrosses made and populations being evaluated–– Evaluating 6000Evaluating 6000--8000 inoculated rows/year8000 inoculated rows/year–– Evaluate whenever natural disease developsEvaluate whenever natural disease developspp–– Screen FScreen F33 to Fto F88

Panicle Blight ReactionsPanicle Blight ReactionsPanicle Blight ReactionsPanicle Blight Reactions

Very Susceptible Susceptible

Moderately Susceptible

Moderately Resistant

CL131 CL161 Catahoula JupiterBengal Cheniere Hybridsg yTrenasse CocodrieNeptune CL151NeptuneWells

CL151CL171

10 BPB resistant lines, including source 10 BPB resistant lines, including source varieties, germplasm, and breeding lines, varieties, germplasm, and breeding lines,

are available by requestare available by request

LM-1NPB/CCDR

NipponbareNipponbareLM‐1/CCDR

Jupiter LR2065/CCDRJup te /

LM‐1/CCDR CCDR/LR2065NBP(MCR00 2190 C93 137 LR2065/CCDRNBP(MCR00‐2190 C93‐137 KATY/CPRS/JA85)

LR2065/CCDR

SummarySummaryCultural management ineffectiveCultural management ineffectiveChemical control unlikelyChemical control unlikelyChemical control unlikelyChemical control unlikelyDisease resistance main area of effortDisease resistance main area of effortSome progress towards developing Some progress towards developing diseases resistance including four sourcesdiseases resistance including four sourcesRequest seed fromRequest seed from:: Don GrothDon Groth

Rice Research StationRice Research StationRice Research StationRice Research Station1373 Caffey Road1373 Caffey RoadRayne LA 70578 USARayne LA 70578 USARayne, LA 70578 USARayne, LA 70578 USA

dgroth@agcenter.lsu.edudgroth@agcenter.lsu.edu