Development of a Growing Degree Day Model for Plant Growth ...
Transcript of Development of a Growing Degree Day Model for Plant Growth ...
DevelopmentofaGrowingDegreeDayModelforPlantGrowthRegulatorsOnUltradwarfBermudagrassPu=ngGreens
WendellJ.Hutchens1,WilliamC.Kreuser2,andJamesP.Kerns1
1DepartmentofEntomologyandPlantPathology,NorthCarolinaStateUniversity2DepartmentofAgronomyandHorLculture,UniversityofNebraska-Lincoln
Introduc*on
Plantgrowthregulators(PGRs)arefrequentlyappliedonultradwarfbermudagrasspu=nggreens.PGRsareoTenappliedtoincreaseballrolldistance(i.e.greenspeeds),reduceexcessiveclippingyields,allowforreducedmowing,andprovidemoreconsistentplayingcondiLons.PGRapplicaLonintervalsforultradwarfbermudagrasspu=nggreensarenotwellcharacterized.ThereisconcernthatPGRsareappliedtoofrequently,leadingtoincreasedbioLcandabioLcstresses.ManyultradwarfbermudagrasssamplessubmiXedtotheNCSUTurfDiagnosLcsLabfordiseasediagnosishaveoTenbeentreatedwithfrequent,highratesofPGRs.Growingdegreeday(GDD)modelsareusedtodeterminewhenchemicalsshouldbeappliedbasedonweatherpaXerns.GDDmodelshavebeenconstructedforPGRsoncoolseasonturfgrasses,butnotultradwarfbermudagrass.ThesemodelsarebeneficialtogolfcoursesuperintendentsallowingformoreaccuratePGRapplicaLonLmings.TwocommonPGRslabeledforultradwarfbermudagrasspu=nggreensincludetrinexapac-ethyl(PrimoMaxx)andprohexadionecalcium(Anuew).TheinfluenceofPGRsonballrolldistanceandturfqualityisvitalforgolfcoursesuperintendentsmanagingultradwarfbermudagrasspu=nggreens.
Objec*ves1. DevelopgrowingdegreedaymodelsforvariousPGRs
2. DetermineeffectsofPGRsonballrolldistanceandturfquality
DiscussionGrowingdegreedaymodelsrevealedthataverageapplicaLonintervalsare170.84GDDforAnuewatthe0.056g/m2rate,152.6GDDforAnuewatthe0.112g/m2rate,and215.13GDDforPrimoMaxxatthe118.294ml/m2rate
PGRsshouldnotbesolelyappliedonacalendarbasisApplicaLonsonAugust2,2016resultedinregulaLonunLllateSeptemberPGRapplicaLonshadminimalimpactonballrolldistance
PGRsonlyhadanegaLveeffectonturfqualityfor1-2weeksaTereachapplicaLon
GrowingDegreeDayModels
Fundingprovidedby
WheelerTurfResearchFarm• StudyperformedfromJuly5,
2016-September27,2016atLakeWheelerResearchStaLoninRaleigh,NC
• PGRsPrimoMaxx(118.294ml/m2)andAnuewattwodifferentrates(0.056g/m2and0.112g/m2)appliedonJuly5,2016andAugust2,2016
• TreatmentsarrangedinaRCBDwith3replicaLons6mlm2
• Clippingscollected2-3Lmesperweek
Methods
• Clippingswereovendriedfor24hoursat60°C• Sandwasseparatedusinganelectricrazortovibrateanovenpanpropped
ata~30°angleandclippingswereweighed
• BallrollmeasurementsweretakenintwooppositedirecLonsusingaSLmpmeter®andturfqualitywasvisuallyassessed
• DataanalysiswasperformedusingSASandgrowingdegreedaymodelswereconstructedusingSolverinMicrosoTExcel
• GDDesLmatesusedabase10°Ctemperature
Anuewat0.056g/m2rate Anuewat0.112g/m2rate
PrimoMaxxat118.294ml/m2rate
Figure1.Surveyconductedfor~300golfcoursesuperintendents(GIEMediaInc.,2015)
References
“Controlledgrowth.”GolfCourseIndustry,30June2015,hXp://www.golfcourseindustry.com/arLcle/pgrs-063015-pgr-research-criLcal/.Accessed8Dec.2016.NCSUTurfPathology.Trivia4me!Whichsideofthis'Champion'bermudagrassgreenreceivedaPGRapplica4onrecently??.13June2015.TwiXer.hXps://twiXer.com/ncturfpathology.Accessed9Dec.2016.
Figure5.Anuewat0.056g/m2rategrowingdegreedaymodel Figure7.Anuewat0.112g/m2rategrowingdegreedaymodel
Figure6.PrimoMaxxat118.294ml/m2rategrowingdegreedaymodel
Figure2.UltradwarfbermudagrassontherightexhibiLngphytotoxicityfromarecentPGRapplicaLon(NCSUTurfPathology,2016)
Figure3.Sandsepara*ngmechanism
Figure4.Clippingcollec*on
PGR Rate JulyGDDInterval
JulyMaximumSuppression
AugustGDDInterval
AugustMaximumSuppression
AverageGDDInterval
AverageMaximumSuppression
Anuew 0.056g/m2 191.32 81% 150.35 80% 170.84 80.50%
Anuew 0.112g/m2 170.92 81% 134.27 87% 152.6 84%
PrimoMaxx 118ml/m2 281.21 73% 149.04 91% 215.13 82%
GrowingDegreeDayModelResults
Table1.ApplicaLonintervalsandmaximumsuppressionforeachPGR
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Figure8.EffectofPGRsonballrolldistance
Figure9.EffectofPGRsonturfquality
Anuew0.056g/m2 Anuew0.112g/m2
PrimoMaxx118.294ml/m2 Control
Figure10.Plot2weeksaTerapplicaLonofAnuewat0.056g/m2
rate
Figure11.Plot2weeksaTerapplicaLonofAnuewat0.112g/m2
rate
Figure12.Plot2weeksaTerapplicaLonofPrimoMaxxat118.294ml/m2rate
Figure13.Plot2weeksaTernoapplicaLonofPGR
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