IntheStrikeZone

Weather

CombinedwithacoollatterhalfofMarch,achillyandsometimesfreezingstarttoAprilputthebrakesonspringandplantgrowthinthecentralandeasternportionofthestate.ColumbiaandSt.Louisare2–4degreesbelownormalforAprilandhaveexperiencedafewfrostsinthepastfewdays.Conversely,KansasCityandSpringfieldareadegreeortwoabovenormaltemperatures,andareprogressingconsiderablymorequicklyintospringthantheEast.ThisisanoddtemperaturedichotomysincetheprogressionintospringisnormallyswitchedwithSt.LouisbeingaheadofKC.Mostareasofthestatereceivedsomerain,withtheI-44corridorgettingthemostoutoflastweek’sstorms.ColumbiaandtheKansasCityareaarestillalittledry,running0.5–1inchbelownormalthusfarinApril.ForecastsindicatetemperatureswillriseinthroughthemiddleofApril,whichshouldputusontrackforfungicideapplicationthresholds(seebelow).Alongwiththistemperatureincrease,wealsohaveadecentchanceforrainfallacrossthestateoverthenexttwoweeks.Abitofdollarspotandpotentiallyalotoflargepatchcouldresultfromtheseconditions.

IntheStrikeZone

QuickHits:

• FairyRingPreventionwithDMIs:Byallforecastsandtrends,theentirestatewillbe

squarely“inthezone”forthefirstoftwopreventiveDMIapplicationsforfairyringcontrolongolfputtinggreens.The5-dayaverage2”soiltemperatureinSpringfield

IntheStrikeZone

havereachedandstayedinthe55-60FthresholdrangefromApril6thtilpresent.KansasCityhasflirtedwiththerangesinceApril5thdivinginandout,whileSt.LouisandColumbiahavebeenoutofrange.Withcurrentdailysoiltemperaturesbackintothelowtomid50sandtheforecastsindicatingawarmingtrendovertheweekend,Iexpecttheentireregionwillbeintherangebynextweek.Torecapthestrategybriefly,(whichcanalsobefoundinmoredetailhere),nextweekwillbethetimeinMissouriforalowrateapplicationofoneoftheDMIfungicidestriadimefon(i.e.Bayleton),tebuconazole(i.e.Torque),triticonazole(i.e.Trinity),ormetconazole(i.e.Tourney).Twentyeightdayslatermakeasecondapplication.BothapplicationsMUSTbewateredinwith1/8–¼inchofpostapplicationirrigation,preferablyimmediatelyaftertreatment.IhadaninquirylatelastweekfromaMissourisuperintendentwhohadmadetheapplicationinearlyMarchduringourearlyscareofspringtemperatures.Ifalsointhisboat,don’tfeellikethiswasawastedapplication,sinceyoumayhavestavedoffsomeearlydollarspotactivity.Idorecommendathreeapplicationstrategy,however,makingthesecondapplication28daysfromthefirstinApril,andathirdapplication28dayslaterinMay.Thissplit-split-splitapplicationstrategywillprovideabetterresidualandmoreeffectivelyprovidefairyringcontrol.

• PowderyMildewonKentuckyBluegrass:Ididobserveanextremelyminorpowdery

mildewoutbreakonfall-seeded‘HGT’Kentuckybluegrasslawnlastweek.Thespotgetsabitofeveningshade,andtheconstantwetleavesandyoungsusceptibleleavesmadeforaprimeenvironment.Thisdiseaseisnormallyjustamildnuisanceandcuriosity,usuallydoingverylittledamagetoKentuckybluegrassinthisregionandrequiringnofungicidetreatment.Theoddwhitepowderymyceliumcoveringtheleafbladescanraisetheeyebrowsofahomeowner,butdoeslittleharmtotheplantandwilldonoharmtothem,theirchildren,orpets.

IntheStrikeZone

StrikeOutLargePatchNow

Alongwithbeinginthestrikezoneforfairyringprevention,it’salsotimetohittheplateforpreventinglargepatchinareasthatareprone(saturated,lowlying,orshadyareas)andhaveahistoryofthedisease.Ourresearchconsistentlyshowsasinglefungicideapplicationmadeinearly(ondormantzoysia)orlateAprilwhenzoysiahasgreeneduptoapproximately50%providesbettercontrolthansingleapplicationsmadethepreviousfall.InMissouri,springisourseasonforthemostextremelargepatchsymptomsandspread.Additionally,homeownersandsuperintendentsalikeexpectasolidspringgreenupthatwillproducepristineturfoverthenextsixmonths.Asevereepidemicoflargepatchnowcansetthatprocessbackandallowweedencroachment.Expectingoneoreventwofallfungicideapplicationstolastthroughthefallandmeltofsnowandrainforthe6-7monthsuntilMayorJuneisastretch.Inahomelawnsituationwithlargepatchhistoryandwhereyoumightonlygetonefungicideapplicationtotargetthisdisease,thisisthetimetotakeit.Ongolffairways,ifasingleapplicationwasmadelastfallitshouldbesupplementedwithanotherthisspringtoensurecontrolonprimelargepatchareas.Iftwofallapplicationsweremade,scoutroutinelyandbereadytohitbadareasiftheystarttofire.Notsureifapropertyhashadahistoryoflargepatch?Googleit!DownloadGoogleEarthandsurveyafairlyconsistentrecordofsatelliteimageryofdifferentseasonsfromthepast13years.Payattentiontofall(Sept–Nov)andspring(Apr–Jun)months,and,asthenameimplies,severeinfestationsoflargepatchshouldbefairlyapparent.GoogleEarthshouldbealsousefulfordeterminingthehistoryofotherturfgrassortreerelatedproblems,andwouldbeagreattoolforturfgrassmanagersmaintaininganew,unfamiliarsite.

IntheStrikeZone

LeeMillerFollowonTwitter!@muturfpathLikeonFacebook!MizzouTurfgrassExtensionTurfgrassPathologist-UniversityofMissouri