Hydroponics11:00‐12:30 FineTuningNutrientSolu;onandIrriga;onManagement

2:00‐3:00 ChoosingVarie;esforHydroponicProduc;on

4:30‐5:30 BiologicalandChemicalInsectControlinGreenhouses

The 2012 Educational Program Committee is pleased to share conference educational materials with you under the condition that they are used without alteration for educational and non-commercial use only. All materials are protected by copyright law. The authors kindly request their work is properly cited, including the date of publication. For more information on Small Farms, visit our website at: http://smallfarms.ifas.ufl.edu or contact your local County Extension Agent. For inquiries about this topic, please contact: Danielle Treadwell, Educational Program Chair. Phone: (352)-273-4775 E-mail: ddtreadw@ufl.edu Suggested Citation: Author Full Name. Title of Presentation or Handout. 2012 University of Florida-IFAS and Florida Agricultural and Mechanical University-CAFS Florida Small Farms and Alternative Enterprises Conference. July 27-29, Kissimmee, FL.

Floa;ngHydroponicLeJuceManagement

RonnieSchnellJuly28,2012

Floa;ngHydroponicSystems

Op;mumNutrientSolu;on•  Whatistheop;mumNrateforfloa;nghydroponicleJuce

produc;on?•  Createdarangeofnutrientconcentra;ons

–  0,22,56,91,125,159,193ppmN–  UsingCaNO3and3‐13‐29(tomatospecial)

•  Watervolumethesameforeachtreatment•  Amountofnutrientsolu;onaddedchanges•  CreatedECvaluesfrom0.5to3.0mSpluscontrol(wateronly)•  WhatistheeffectonleJuceyield,andquality?•  WillhighlevelsofNinsolu;onresultinhighlevelsofNO3in

;ssue?•  Color?

GreenhouseExperiment

ImpactofFer;lizerTreatmentsonEC

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

0 7 14 21 28 33

ECm

S

Daysa*erTransplan1ng

193ppmN

159ppmN

125ppmN

91ppmN

56ppmN

22ppmN

0ppmN

LeJuceYield

LeJuceColor

LeJuceColorandYield

TissueNO3‐NConcentra;on

Solu1onStrengthN(ppm)

22 56 91 125 159 193

Poundsaddedper1000gallonsofsolu;on

N 0.19 0.47 0.75 1.04 1.33 1.61

P2O5 0.10 0.25 0.40 0.56 0.71 0.86

K2O 0.42 1.06 1.71 2.36 3.00 3.65

Ca 0.16 0.41 0.66 0.92 1.17 1.42

Mg 0.09 0.24 0.38 0.53 0.67 0.82

AmountofNutrientsAdded

1000gal=400d2about4inchdepthofsolu;on400plants@1plantpersqd

NitrogenUptakeEfficiency

PhosphorusUptakeEfficiency

PotassiumUptakeEfficiency

SummaryofNutrientSupply

•  90‐125ppmN or•  0.75‐1.0lbsper1000galofN•  Abouta2:1:4ra;o(N‐P2O5‐K2O)•  SupplysufficientNfor400leJuceplants

– Op;mizeyieldandquality– Minimizenitrateaccumula;on

EffectofRainfall•  Largeraineventswilldilutethesolu;on•  Withoutoverflow,nutrientsares;llthere•  Atwhatpointorlevelofdilu;onwouldadjustmentsbeneededtothegrowingsolu;on?

•  Startedwith125ppmN(EC~1.5)•  Imposedtheequivalentofa0.5,1.0,1.5,2.0,2.5and3.0inchrain

•  Comparedtocontrol(nowateradded)•  Totalamountofavailablenutrientdoesnotchange,watervolumedoes

•  MeasuredleJuceyield,qualityandnutrientuptake

Dilu;onEffect–SimulatedRainfall

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

ECm

S

DaysA*erTransplan1ng

3.0in

2.5in

2.0in

1.5in

1.0in

0.5in

0in

LeJuceYield

NUptakeEfficiency

EffectsofDilu;onbyRain

•  Inaddi;ontoyieldandNuptake:– DidnotimpactPofKuptakeefficiencies– DidnotimpactnitratelevelsinleJuce;ssue– Didnotimpactcolor

Whatdoesthismeanformanagement?

•  Star;ngwiththerightamountofnutrientsiscri;cal.

•  Fluctua;onsinwatervolumewillnotimpactyieldorquality.

•  Maintainingasufficientamountofwaterisnecessary.

•  Overflowoftanksresul;nginmasslossofnutrientscouldreduceyieldandquality.

WhentoReplenish

•  ThemajorityofNandKwereconsumed.

•  Smallerpropor;onsofappliedP,Ca,andMgconsumed.

•  Findingtheperfectmixmaybedifficult.

•  Replenishadereachharvest.

•  Periodicflush

Summary

•  90‐125ppmNO3‐Nwasop;mumforproduc;on

•  0.75–1lbNper1000gal=400plantsor•  0.2–0.25lbofactualNper100plants•  Maintainaminimumwaterlevel•  Noneedtoadjustforfluctua;onsinwaterlevelduetorains.

•  Replenishnutrientsadereachharvest.