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Purdue Methods for Corn Growth Plant Growth Facility

3-1-2010

Optimizing Greenhouse Corn Production: WhatPrevents Calcium Deficiency?Jeannie RossPurdue University, jmross@purdue.edu

Robert EddyPurdue University, robeddy@purdue.edu

Daniel T. HahnPurdue University, dhahn@purdue.edu

Follow this and additional works at: http://docs.lib.purdue.edu/pmcgPart of the Horticulture Commons

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Recommended CitationRoss, Jeannie; Eddy, Robert; and Hahn, Daniel T., "Optimizing Greenhouse Corn Production: What Prevents Calcium Deficiency?"(2010). Purdue Methods for Corn Growth. Paper 7.http://docs.lib.purdue.edu/pmcg/7

ThisdocumentisbasedonmaterialsoriginallypostedtothePurdueUniversityHLADepartmentPlantGrowthFacilitywebsite:http://www.hort.purdue.edu/hort/facilities/greenhouse/CornMethod.shtml

Whatpreventscalciumdeficiency?Calciumdeficienciesofcorn,oftencalled“buggy‐whipping,”arefairlycommoninagreenhouse.Themostcommonandtroublesomecalciumdisorderoccursintheseedlingstage.Emergingleavesaredamagedanddon’tunfurl.Distortionandtwistingresultsasnewerleavestrytopushthroughthedamagedleaves(seeFigure1).Sometimestheplantrecovers,buttoooftenthegrowermustcarefullyunfurltheleavesmanuallytosaveit.Certaingeneticlinesexhibitthedisordermorethanothers,anditismuchmoreprevalentinlowlightofwinter.Aseconddisorderblamedoncalciumdeficiencycanappearduringtherapidgrowthstageoftheplant,typicallyinsummer,withserratededgesofnewleaves.Thisseemstobemoreenvironmentalthangenetic,andplantstypicallygrowoutofit.Itisdifficulttotellifitisacalciumdisorderoraburningoftheleafedgeasxylemsapisforcedoutofleafthroughaprocesscalledguttation(seeFigure2).Guttation,prevalentingrasses,hasbeenlinkedtoleafdamagefromsaltsinthefluid(Ivanoff,1963).Calciumistakenuppassivelybyroots,sotranspirationrateaffectscalciumlevelinplants.Onceintheplant,calciumcannotbetranslocatedintoothertissue.Thisiswhydisorderstypicallyshowupinnewlyformingtissueswhenenvironmentalconditionsdisfavortranspiration.Inanortherngreenhouse,thismaymeanlowlightofwinter,accompaniedwithhighhumidityduetothegreenhousecoolingventsstayingclosedforlongperiods.Evenifcalciumlevelsintheplantasawholearesufficient,sometimestheplantcan’tgetenoughcalciumintorapidlyexpandingtissue,whereitisneededforcellwallgrowth,amongotherfunctions.PoinsettiaBractEdgeNecrosisandtomatoBlossomEndRotaretwoclassicgreenhousecalciumdisorders.Calciummanagementmethodsincludemakingsureadequatecalciumissuppliedwhilecreatinganenvironmenttoimprovetranspiration,includingproperhumidityandairmovement.Toensureadequatecalciumisapplied,oneresearchcompanystartscornplantsinsmallcontainerssothattheyarewateredmorefrequently,usingasolutionof400ppmCa.AsimilarmethodisdescribedintheprotocoloftheIowaStateUniversityPlantTransformationFacility(Anonymous,2009),includingnutrientsolutionrecipes.NolanShumwayofPurdueBotanydepartmenthasnearlyeliminatedcalciumdisordersofcornbyinstallingsupplementallightsysteminthegreenhousecapableofadding600‐700µmol/m2/s.

Sincethisisnoteconomicallyfeasibleformanyfacilities,wepursuedothermeans.Interestingly,ourattemptstomatchthedailylightintegral,orsolaraccumulation,ofShumway’ssystembyapplying400µmol/m2/slightfromfluorescentlampsfor24hoursonlymadethecalciumdisorderworse.Usingcornlinesthatexhibitedcalciumdeficiencyimmediatelyaftergerminating,welookedatapplyingcalciumtotheplants,totherootmediumortheseedsthemselves(seeExperiments19,21‐24inMaterialsandMethods).Thoughsomeofthesemethodsareeffectivewithpoinsettiaandgreenhousetomato,noneworkedwiththesecornlines.Themethodsincluded:calciumsprays,calciumsoildrenches,calciumsolutionsinthewhorl,calciumseedsoaks,ultrasonicseedtreatmentfollowedbycalciumseedsoaks.Theonlyimprovementwesawwasbyloweringtemperatureduringgerminationandearlygrowth(seeTable1).Thiscameatthecostofgrowthrate.Plantsatthelowertemperaturewereafullleafstagebehindtheplantsathighertemperaturesandweremuchshorter(datanotshown).Wesuggestthismaybejustonemoretoolforthetoolbox.Puttingitalltogether,itmaymakesenseforresearcherstoidentifygeneticlinespronetothisearlycalciumdisorderandsetupaspecialpropagationarea.Thiswouldlimittheextralaborandequipmentexpensetojusttheselines.Theareacouldhaveacombinationofsupplementallightof600µmol/m2/s,atransplantingprotocol,high‐calciumfertilizer,optimumairmovement,andthecapabilityforlowertemperatures,ifrequired.

Figure1.Left:Calciumdisorderofyoungcornseedling.Right:Disorderinsummergreenhouseduringrapidgrowthstage,eithercalciumdeficiencyorguttationdamage.

Table1.PercentageofplantsexhibitingCadeficiencysymptomsrequiringmanualunfurlingtokeepplantgrowingindifferenttemperatureandlightenvironmentsofExperiment20. Highlight

425µmol/m2/sLowlight

145µmol/m2/s26.7°Cday/21.1°CnightGreenhouse 65* 50**

26.7°Cday/21.1°CnightGrowthchamber 21 42

23.9°Cday/23.9°CnightGrowthchamber 20 4

21.1°Cday/15.6°CnightGrowthchamber 0 0

*Ambientgreenhouselightwithapproximately100µmol/m2/sHIDsupplementationfor16hoursdaily.**Sameas“Highlight”treatmentbutwith50%shadecovering.

Figure2.Guttationincornleaves,whenxylemsapisforcedthroughleafhydathodesthroughrootpressure.