Winter Production in High TunnelsLiz Maynard, Dept. of Hort and LA, PurdueMichael O’Donnell, Purdue ExtensionDavid Robb, Eden Prairie FarmJanuary 12, 2017 Indiana Horticultural Congress 1

FallandWinterVegetableProductioninProtectedStructures• CivilEatsarticle–

http://civileats.com/2017/01/03/winter-the-hottest-thing-in-farming/“Winter:TheHottestThinginFarming”Newtechnology—andgrowingdemandforlocalfood—ismakingwinterfarmingmorepossiblethanever

• Productionofcoolseason/coldhardycrops inlowtunnels,unheated(cold)andminimally-heated(cool)hightunnels,withstrategicuseofrowcovers.

FallandWinterVegetableProductioninProtectedStructures• Greatwaytodiversifyuseofexistingstructures.

• Greaterincomepotentialpersq ft withcoolseasoncrops?E.g.,MSUExtensionBulletinE-3112,ModelBusinessPlanforSeasonExtensionwithHoophouses

• Moreresources*availableasmoregrowersenterthisspace….andresearchersreact!

• Lotsofquestionsremain:bestpractices(timing,varieties),yieldpotential,financialbenchmarks

• And,eachfarmmicroclimateisunique(alongwithyourfoodshed’s markets).

• Babyleafgreens,Full-sizeleafvegetables,Headvegetables,Rootcrops

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• http://www.timeanddate.com/sun/

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So…..Whatcrops? Timingandplantingconsiderations?

DS9-1(Arugula)

10-28

DS10-10(Mizuna)

5

6

Taken1-27

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+beet,carrot(butconsiderversusstoragecrop)8

Fall-winter production

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• ShorterdaysandfewerGDDsandlesslightrequirelongerDTM(moreonthislater…)

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• http://www.timeanddate.com/sun/

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So…..Whatcrops? Timingandplantingconsiderations?

10Hartman, Ben. The Lean Farm. 2015. p.181

Fall-winter production

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• Forcropsharvestedduring‘Persephone,’planforsequentialharvestofcropsthatreach~maturity/sizebystartof‘Persephone.’Continuewithsequentialplantingsthatwillresumegrowthas‘Persophone’ends(beingawareofcrophardiness).

• Sunrise-SunsetCalculatorhttp://www.timeanddate.com/sun/ E.g.,Muncie,Nov13– Jan28

• Resourcesexisttohelpwithscheduling– JSS,MSU,…andsoonfromPurdue

• But,keeprecordstoinformplantingsyeartoyear– woodstakes+waterproofmarkers!

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So…..Whatcrops? Timingandplantingconsiderations?

MSUtable

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BabyKaleinMuncieLast10-HourDay==Nov.13

S Seedlast weekSep.à firstweekOct.Kale(fullleaf)inMuncie

S StarttransplantsAug.1-15,TPSep.1-15weekSep.à firstweekOct.

JSSWinterGrowingGuide

Fall-winter production

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• http://www.timeanddate.com/sun/

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• Minimally-heatedhightunnels(keepingTmin >~27F)canresultinsignificantyieldincreaseandpermitgreatercropdiversityforDec-Febharvest

So…..Whatcrops? Timingandplantingconsiderations?

Coleman, Eliot. The Winter Harvest Handbook. 2009. p.11

Coleman, Eliot. The Winter Harvest Handbook. 2009. p.11

ClayBottomFarm– The“LeanFarm”

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RiverRidge Farm– Atrue4seasonfarm!9/23

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10/13

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1-2-2017

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TP11-2H12-22(ready)

TP10-26H12-14

TP12-22H??

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Environment

StructureConsiderations– HighTunnels

Photo:RutgersUniv.EcoComplexPhoto:PetrusLangenhoven

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SupportsnowloadShedsnowfromroofFrost-freewatersourceInternalrowcoverVentilationPossibly:

–Heatsource–Heatstorage

PolycoveringtrapsheatfromsunAirandsoilwarmup

ManagingEnvironment

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Light=HeatHeatstorage=soilandsoilwaterHeatloss=• Convection(wind)• Radiation• Conduction(warmtouching

cold)

AtnightheatradiatesfromsoiltoairHeatislostthroughplastic

KeepingHeatInTunnel

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Outercovering:Reduceslossofheatbyradiationandreduceswind• Airbetweenlayersofplasticinsulates• PlasticitselfisNOTagoodinsulatorRowCovers:Insulateandreducewindreducelossofheatbyconduction,convectionandradiation,increasinghumidityaroundcropHeatsinks:absorbheatandreleaseitslowly• Soil• Water Rowcoverinsidetunnelreducesheatloss

DatafromCB,2016

Air Temperature and Solar Radiation for a Week in February

2016Air temp in tunnels increases quickly when the sun comes out.

Air under row cover in tunnel

Air above row cover in tunnel

Air outside

RR_min_air-temp-vs-date-overlayRR_daily-radiation-and-DLI-graph Daily Solar Radiation and Light

Minimum temperature determineswhat will surviveUnder row cover 5-10°F warmer than above, 10–20°F warmer than outside

CB_Mnthly_GDD40

Ave.TemporGrowingDegreeDaysGrowingdegreedayaccumulationdetermineshowquicklyplantsgrow

(High+Low) – 40=GDD402

Example:[(60+26)/2]– 40=3GDD40

Yield of kale cultivar ‘Black Magic’ at RR.

EP DLI and SR

DailyLightIntegral(DLI)DLIbelow10:littleplantgrowth

CB

J F M A M J J A S O N D J

Hours of Daylight

10

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DailyLightIntegral(DLI)DLI<10Mid-Nov.toEndofJan.

CorrespondstoDayslessthan10hours

Eden Prairie Farm

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RecordkeepingIdeas

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EDENPRAIRIEFARM,EDEN,IN

EDENPRAIRIEFARM,EDEN,IN

Recordkeeping Ideas

THANKYOUQuestions?Liz Maynard

Vegetable SpecialistDepartment of Horticulture &

Landscape ArchitecturePurdue University

Tel. 219-548-3674emaynard@purdue.edu

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Michael O’DonnellOrganic and

Diversified Ag EducatorPurdue Extension

Tel. 765-747-7732modonnel@purdue.edu

David RobbOwner and FarmerEden Prairie FarmTel. 317-250-5105

davidrobb@netdirect.net

This project was supported by a NCR SARE Partnership Grant through subaward H004403722 to Purdue University from USDA Award 2014-38640-22156 to the University of Minnesota. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the USDA or the U.S. Government.