Management Of Closely Spaced Trees

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Title:
Management Of Closely Spaced Trees
Physical Description:
Fact sheet
Creator:
Wheaton, T.A.
Publisher:
University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication:
Gainesville, Fla.
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Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status:
Published
General Note:
"Publication date: January 1993."
General Note:
"HS-157"

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University of Florida Institutional Repository
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University of Florida
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All rights reserved by the submitter.
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IR00004631:00001


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FactSheetHS-157 January1993ManagementofCloselySpacedTrees1 T.A.Wheaton,J.D.Whitney,D.P.H.Tucker,W.S.Castle2Atrendtowardsspacingtreesclosertogetherin therowbeganinthe1960sinFloridaandhas continuedtothepresenttime.Treesplanted10-15 feetapartintherowrapidlygrowtogethertoforma continuoushedgerowastheymature.Growershave expressedconcernthatthecontinuoushedgerowmay bealessefficientproductionsystemduetoa reductioninlightpenetrationandfruitingsurface area.Possiblealternativestoacontinuoushedgerow includeinterruptingthehedgerowbycrosshedgingor removalofsometreestoleavespacesinthe hedgerow.Spacescreatedbythesemethodscouldbe leftbetweeneverytree,ortherecouldbegroupsof two,three,orfourtreesseparatedbyanopening. Anumberof5-yearexperimentswerebegunin 1979todetermineifspacescreatedinahedgerowby crosshedgingortreeremovalwouldaffectyield,fruit size,fruitcolor,orjuicequality.Grovesusedincluded early,mid-seasonandlatevarietiesoforangeson conventionalrootstocks.Allgroveswereplanted25ft, betweenrowsandwere7-28yearsoldatthe beginningoftheexperiments.Allexperiments includedhedgerowplotsinadditiontocrosshedging ortreeremovalplots.Someexperimentsincluded annualtoppingofhedgerowsatvariousheights.The remainderofthissectionpresentstheresultsofthese experiments.CROSSHEDGINGYieldwasreducedmostyearsbycrosshedging, andcrosshedgingtocreateaone-treeunitreduced yieldmorethanforatwo-treeunit.Yieldwas significantlyreducedinover50percentoftheplots duringthe5yearsoftheexperiment.Averageyield wasgreatlyreducedbycrosshedgingfor2-treeunits in4outof7experiments,andfor1-treeunits,in5 outofthe7experiments.Treeswereonly7-yearsold atthebeginningofoneexperimentandwerenotyet touchingintherow.Yieldwasnotreducedduringthe firstyearsofcrosshedging.However,asthetrees startedformingahedgerow,crosshedgingreduced yieldinthisexperimentalso. Crosshedgingdidnotaffectfruitsize,external fruitcolororjuicequality.Inoneexperiment,it appearedthatcrosshedgingresultedinmoresevere freezedamage.Also,weedgrowthwasamoreserious probleminthespacesopenedbycrosshedging.TREEREMOVALIn-rowtreespacingswereapproximately10feet inthetreeremovalexperiments.Inoneexperiment, yieldexpressedonaperacrebasiswasreducedthe firstyearbutnotinsubsequentyears.Infact, 1.ThisdocumentisFactSheetHS-157,aseriesoftheHorticulturalSciencesDepartment,FloridaCooperativeExtensionService,Institute ofFoodandAgriculturalSciences,UniversityofFlorida.Publicationdate:January1993. 2.T.A.Wheaton,ProfessorandHorticulturist;J.D.Whitney,ProfessorandAgriculturalEngineer;D.P.H.Tucker,Professorand Horticulturist;W.S.Castle,ProfessorandHorticulturist,CitrusResearchandEducationCenter,LakeAlfred,Florida,Cooperative ExtensionService,InstituteofFoodandAgriculturalSciences,UniversityofFlorida,GainesvilleFL32611. TheInstituteofFoodandAgriculturalSciencesisanequalopportunity/affirmativeactionemployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,age,handicap,ornational origin.Forinformationonobtainingotherextensionpublications,contactyourcountyCooperativeExtensionServiceoffice. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/ChristineTaylorStephens,Dean

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ManagementofCloselySpacedTrees Page2considerableyieldcompensationoccurredeveninthe firstyear.Forexample,removalofeveryfifthtreeto forma4-treeuniteliminated20%ofthetrees,but reducedyieldbyonly10%.Inasecondtreeremoval experiment,reductionsinyieldoccurredmostyearsof theexperiment.Again,yieldreductionsthefirstyear werenotasgreatasexpected.Removalofeveryother treetoform1-treeunitscauseda50%reductionin thenumberoftrees,butonlya25%reductionin boxesoffruitperacrethefirstyear.Yieldreductions duetotreeremovalwerelessinsubsequentyears. Treeremovaldidnotaffectaveragefruitsize, externalfruitcolor,orjuicequality.Aswithcross hedging,weedgrowthwasamoreseriousproblemin spacescreatedbytreeremoval.Treesadjacentto openingsleftbytreeremovalgrewrapidlyintothe opening.Thisextensiongrowthwouldreformthe hedgerowinafewyearsunlesscrosshedgingwas performedperiodically.Atclosein-rowspacings,tree removalmaybeamoredesirablemethodofcreating spacesinthehedgerowthanbiennialcrosshedging. Neithercrosshedgingnortreeremovalimproved yield.TOPPINGThreeof4experimentsincludedtoppingheights of15and18ft.Inoneofthesewherelittlefoliage wasremovedbytopping,yieldwasnotreducedby toppingatthelowerheight.Intheother2 experiments,toppingatthelowerheightreduced yieldsomeyears.Thefourthexperimentincluded12, 15,and18ft,toppingheights.Yieldswere substantiallyreducedbytoppingtothelowerheights. Comparedtothe18ft.height,yieldwasreducedthe firstyear65%atthe12ft.heightand35%atthe15 ft.height.Somecompensationoccurredinsubsequent yearsasthefruitingzonemoveddownontrees toppedatthelowerheights.However,yield reductionsatlowerheightspersistedthroughoutthe experiment. Averagefruitsizeincreasedasaresultofthe substantialyieldreductionsfromsometopping treatments.Externalfruitcolorwasnotaffected.Juice brixwasreducedbytoppingtolowerheightsinmost oftheexperiments.Intheexperimentinvolving12, 15,and18fttoppingheight,averagejuicebrixwas about0.5unitslowerforthelowesttoppingheight. Regrowthfollowingtoppingwasrapid.This vegetativeregrowthmayhavecompetedwithfruiting, partiallyexplainingthereductioninyieldandjuice brix.Inhedgerows,ahigherpercentageofthefruitis foundinthetop,centerportionofthetree.Fruit fromthisportionofthetreealsocontainsthehighest juicebrix.RESULTSTheresultsoftheseexperimentsdemonstrates thatacontinuoushedgerowisadesirableproduction systemforFloridacitrus.Innocasedidinterrupting thehedgerowbycrosshedgingortreeremoval improveyield,fruitcolor,orjuicequality.The absenceofeffectsoncolororjuicequalitysuggests thathedgerowsshouldbesuitableforthefreshfruit marketaswellasorangesgrownforprocessing. Attemptstomaintainhighyieldsontreestopped annuallyatlowerheightswerenotsuccessful. Althoughannualtoppingisnotacommon commercialpractice,theresultsoftheseexperiments suggestthatmaintainingshorttreesmaybedifficult withoutsomeyieldandbrixreduction.Minimal toppingrequiredtocontroltreeheightorhedgerows shouldbepracticed.