Dr. Erik RunkleDept. of Horticulture

Michigan St. Univ.

Dr. Abhay ThosarSr. Plant Specialist

Philips Lighting

Light Consists of Three Dimensions

Light quantity (intensity)

Light quality (spectrum)

Light duration (photoperiod)

Plant biomass Morphology Flowering

The different properties of light interact to control growth and development of plants

Applications of LEDs on Plants

• Photoperiodic lighting in greenhousesvery low-intensity lighting to regulate flowering• Supplemental lighting in greenhousesmoderate-intensity lighting to supplement sunlight to increase growth• Sole-source lighting indoors (vertical tiers)moderate-intensity lighting that is the only light source

13 14 1615Photoperiod (hours):

Campanula ‘Merrybell Bright Blue’

Regulating Flowering with Photoperiod

Incandescentbulb

Compact fluorescent bulb LED emitter

Purchase price increasesElectrical efficiency increases

Lamp lifetime increases

Lighting Technologies Developing Effective R:FR

Objective: Determine how the red : far-red (R:FR) influences flowering and extension growth of photoperiod-sensitive crops to facilitate the development and use of effective LEDs for flowering applications

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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Efficacy of R:FR for NI Lighting “Flowering Lamps” by Philips

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

300 350 400 450 500 550 600 650 700 750 800

Inte

nsity

(µ

mol

·m-2

·s-1

)

Wavelength (nm)

Deep Red White Far Red

Deep Red White

Far Red

Question: Are the R+W+FR lamps more effective than the R+W lamps, as would be predicted?

Ageratum ‘Hawaii Blue’

After 7 weeks at 68 °F, DLI = 5.7 mol·m-2·d-1

Incan.9-hour day with 4-hour night interruption

R+W R+W+FR9-hour

short day

Petunia ‘Wave Purple Classic’

After 6 weeks at 68 °F, DLI = 5.7 mol·m-2·d-1

Incan.9-hour day with 4-hour night interruption

R+W R+W+FR9-hour

short day

Top

view

Sid

e vi

ew

Nelson J.A. and B. Bugbee. 2014. Economic analysis of greenhouse lighting: Light emitting diodes vs. high intensity discharge fixtures. PLoS ONE 9(6):e99010.

Lamp typeElectrical input (W) Manufacturer and model

Efficiency (µmol·J–1)

High-pressure sodium400-W magnetic 443 Sunlight Supply Sun Star 0.941000-W magnetic 1,004 PARsource GLXI 1.161000-W electronic 1,026 PARsource GLXII 1.301000-W electronic* 1,033 Gavita Pro 1000 DE 1.70

LEDRed + White 423 Hydrogrow Sol 9 0.89Red + White + Blue 304 LumiGrow Pro 325 1.29Red + White 279 Illumitex NeoSol NS 1.40Red + Blue 384 LSG GrowAdvantage Violet 1.70

*This is a double-ended lamp whereas the other HPS lamps are single ended (mogul-base).

Efficiency of Supplemental Lighting

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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Nelson J.A. and B. Bugbee. 2014. Economic analysis of greenhouse lighting: Light emitting diodes vs. high intensity discharge fixtures. PLoS ONE 9(6):e99010.

Lamp typeElectrical input (W) Manufacturer and model

Efficiency (µmol·J–1)

High-pressure sodium400-W magnetic 443 Sunlight Supply Sun Star 0.941000-W magnetic 1,004 PARsource GLXI 1.161000-W electronic 1,026 PARsource GLXII 1.301000-W electronic* 1,033 Gavita Pro 1000 DE 1.70

LEDRed + White 423 Hydrogrow Sol 9 0.89Red + White + Blue 304 LumiGrow Pro 325 1.29Red + White 279 Illumitex NeoSol NS 1.40Red + Blue 384 LSG GrowAdvantage Violet 1.70Red + Blue (+ White) 190-200 Philips GreenPower Toplighting 2.3-2.7

*This is a double-ended lamp whereas the other HPS lamps are single ended (mogul-base).

For LEDs, the efficiencies are rapidly improving

Efficiency of Supplemental Lighting

• Primarily an economic issue– LEDs are 3-6 times the cost of conventional lights

• Situations when LEDs could be more favorable:– High electricity costs and/or limited power supply– Can elicit specific growth/coloration responses– Year-round growing– Can position lights close to crop (vertically or

horizontally)

LEDs for Supplemental Lighting

Great Lakes Hops, Zeeland, MI (2014) Michigan St. Univ., East Lansing (2015)

Wageningen, Bleiswijk, the Netherlands (2013)Photo: OSRAM Opto Semiconductors

Experimental objectives:To quantify how seedlings of popular annual crops acclimate to different wavebands of light

LEDs as Sole-Source Lighting

Consistently produce plants that are uniform and have desirable growth characteristics (e.g., compact, early flowering, etc.)

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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Impatiens ‘SuperElfin XP Red’Seedlings grown at 68 °F for 4 weeks under LEDs

for 18 h·d-1 at PAR=160 µmol·m-2·s-1 consisting of (%):

B=blue, 446 nm; G=green, 516 nm; R=red, 634 nm; HR=hyper red, 664 nm

B0G0R50HR50

B0G50R25HR25

B25G25R25HR25

B50G50R0HR0

B50G0R25HR25

B100G0R0HR0

Salvia ‘Vista Red’Seedlings grown at 68 °F for 4 weeks under LEDs

for 18 h·d-1 at PAR=160 µmol·m-2·s-1 consisting of (%):

B=blue, 446 nm; G=green, 516 nm; R=red, 634 nm; HR=hyper red, 664 nm

B0G0R50HR50

B0G50R25HR25

B25G25R25HR25

B50G50R0HR0

B50G0R25HR25

B100G0R0HR0

Seedlings grown at 68 °F for 25 days under LEDs (33 days after sow)18-hour photoperiod at PPF = 160 µmol·m-2·s-1

MW100 MW75+R25 MW45+R55 MW25+R75 R85+B15 R40+G40+B20

Leaf area (cm2)30.4 a 31.8 a 29.8 a 32.3 a 25.5 b 28.6 ab

Plant height (cm)

5.6 ab 5.7 ab 5.3 abc 5.9 a 4.8 c 5.1 bc

B=blue, 451 nm; G=green, 521 nm; R=hyper red, 660 nm; MW=mint white, 552 nm

Geranium ‘Pinto Premium Deep Rose’ Potential Utility of Far Red LEDs

• While blue light generally suppresses plant elongation, far-red light can promote it

–FR +FR

Vitro Plus, the Netherlands (2011) Green Spirit Farms, New Buffalo, MI (2014)

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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• Daedre Craig, Nate DuRussel, Fumiko Kohyama, Qingwu Meng, Yujin Park, and Brian Poel

• Private horticulture companies, lighting companies, and granting agencies that have financially supported this research including:

Acknowledgments More Lighting Information

www.flor.hrt.msu.edu/lighting

Dr. Abhay Thosar

July 2015

LED LightingWhat does the future hold

Philips Lighting Horticulture

• Light intensity 

– Day Light Integral (DLI) requirements

– Measured in micromoles/m2/sec

• Light duration

– Supplemental lighting

– Photoperiodic lighting

– Sole source lighting

• Light quality (spectrum)

– Sunlight

– HPS

– LED’s

Light requirements of plants

Examples typical spectrum

300nm 800nm

Blue

Deep red

Far redOnly when white LEDs are needed for inspection

Sunlight HPS

Metal Halide Philips production module DR/W/FR

• Conventional greenhouse production

– Under natural light conditions (sunlight)

– Supplemental lighting (HPS)

• Lighting the parts of plant canopy 

where penetration of light is 

very low using Inter lighting

• Possibilities of an

economically viable

winter crop

Applications in High Wire Crops

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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Parameter 2 Line Control

Brix 4.70 (+34%) 3.50

g/Mol 5.83 (+48%) 3.95

Avg. Fruit Weight (g) 285.50 (+20.7%) 236.50

Fruit/m2 63.45 (+18.1%) 53.73

LED Interlighting only:

Trials are currently being conducted in Ontario, Canada and data is revealing interesting results.

Tomato Experience ‐ Beefsteak

TreatmentYield 

(Kg/m2)% 

DifferenceAFW

(Grams)Avg gmper Mol X‐Factor

LED‐IL  5.35 28.3 183 16.57 1.29

Control 4.17 180 12.81

Ontario, Canada, TOV Tomatoes (Cv. Komeet)

Mini Cucumber Experiences

Cucumbers supplied with Philips LED Interlighting will have a different growth habit and leaf size compared to non‐lit crops……

Notice how the leaves are more erect in the non‐lit plants than in the lit plants. Leaf area (size) is also larger in the non‐lit plants.

Mini Cucumber Experiences

Greatest percentage yield advantages are seen in Q4 and Q1 when sunlight values are lowest and fruit prices are highest.

Umbrella mini‐cues:  LED Inter lighting only, no top lighting (Neither HPS or LED)

Average Yield (Kg/m2/week)Average Percentage Difference v. Control

1‐Line  2‐Lines Control

Q1/2014 1.58 39.8% 1.71 51.3% 1.13

Q2/2014 3.14 13.8% 3.44 24.6% 2.76

Q3/2014 2.53 14.5% 2.49 12.7% 2.21

Q4/2014 1.61 27.8% 1.96 55.6% 1.26

• Increased productivity

• Increased plant density

• Tailored nutrition and cultural practices

• Tailored quality

• Winter production

Future of LED’s : High wire crops

• Shorten growth cycle

• Faster rooting

• Consistent plug quality

• Compact plugs

• More basal growth/branching

• Prominent pigmentation

• Less use of PGR’s

• Less use of chemicals

Floriculture crops : annuals and perennial plug production

• Plugs more compact than under HPS (looking to the height of the apical point) Actual height differences not calculated. 

Floriculture applications

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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• Plants under LEDs are more compact than under HPS which indicates a possibility of reduction in the use of PGRs, which would result in labor savings as well as cost of PGRs

LED HPS LED HPS

Lavender plug under LEDs

• Faster root development, possibility of early transplanting 3‐5 days depending on the cultivar

• Possible reduction in the cycle time from seeding till transplant

• Prominent leaf coloration highly desirable for certain cultivars of Sedum; considered as a good selling point for plant quality

Sedum various Cv.

HPS LED HPSLED• Better survival percentage and 

consistent growth of the plants throughout the plug tray

LED

LED

HPS

HPS

• Early flowering and increase in flowering percentage with a good looking plant

LED

LED

LED

HPS

HPS

HPS

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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• Better or more lateral/basal branching improving the look of the crop, without manual shearing or use of PGRs

LED

LED LED HPS

HPS

HPS

Plug propagation – Sole source lighting 

• Controlled environmental conditions• CO2 enhancement• Precise Temperature and humidity control

• Less instance of disease and pests• Better control on the growth of the plants.

• Reduction in the growth cycle time• Reduction in the use of PGR’s

City Farming – Important Considerations  Micro greens – Sole source lighting 

87:13 R:B

84:7:9 R:FR:B

74:18:8 R:W

Daily light integral :6 mol·m–2·d–1

2 modules delivering 105 µmol·m–2·s–1

12 mol·m–2·d–1

4 modules delivering 210 µmol·m–2·s–1

18 mol·m–2·d–1

6 modules delivering 315 µmol·m–2·s–1

http://www.brightbox‐venlo.nl/en

Greenhouses Or Pinkhouses

Runkle (Michigan St. Univ.) and Thosar (Philips) July 11, 2015

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