PRINCIPLES OF LIGHT FOR ORCHID GROWERS Click to

PRINCIPLES OF LIGHT FOR ORCHID GROWERS Click to edit Master subtitle style STAN BETTER JANUARY 2011

LIGHT PRISM • • WHEN THE SUN’S RAYS HIT A PRISM THE VISIBLE LIGHT SPECTRUM IS REVEALED

PRINCIPLES OF LIGHT • • • LIGHT CAN INFLUENCE ALL ASPECTS OF ORCHID PLANT GROWTH AND FLOWERING. LIGHT PROVIDES THE ENERGY FOR PHOTOSYNTHESIS WHICH IS THE PLANT’S ABLILITY TO CONVERT CARBON DIOXIDE (CO 2) AND WATER (H 2 O) INTO SUGARS AND OXYGEN (O 2). LIGHT (AS STEVE HELBLING SAYS) IS “FOOD FOR ORCHIDS”.

LIGHT DURATION • • • DURATION OF LIGHT IN A 24 HOUR PERIOD IS KNOWN AS DAYLENGTH OR PHOTOPERIOD CHANGES THROUGHOUT THE YEAR. MAGNITUDE OF CHANGE DEPENDS ON LATITUDE: AT THE EQUATOR THE CHANGE IS LESS (ABOUT 40 MINUTES) FROM WINTER TO SUMMER. IN CINCINNATI (40 DEGREE NORTH LATITUDE) THE PHOTOPERIOD CHANGE IS ABOUT 7 HOURS (9 HOURS DAY

WHY IS DURATION IMPORTANT? • • PHOTOPERIODS ARE A CONSISTANT ENVIRONMENTAL PARAMETER WHEN GROWING ORCHIDS. YOU CAN PLAN HOW AND WHAT YOU WANT TO GROW BASED ON YOUR REGION. MANY ORCHIDS USE THE CHANGE IN PHOTOPERIOD AS A FACTOR IN SIGNALING THE INDUCEMENT OF FLOWERING.

HOW HAS THE ORCHID GROWER ADDRESSED LIGHT DURATION? • • ORCHID GROWERS HAVE MANIPULATED THE PHOTOPERIOD BY THE USE OF ARTIFICIAL LIGHT EITHER TO SUPPLEMENT NATURAL LIGHT OR AS THE SOLE LIGHT SOURCE AS IN BASEMENT GROWING. BY CONTROLLING THE AMOUNT OF LIGHT, BOTH IN INTENSITY AND DURATION, THE ORCHID GROWER CAN CONTROL THE AMOUNT OF FOOT CANDLES, COLOR, AND PHOTOPERIOD REQUIRED FOR A PARTICULAR

WHAT PHOTOPERIOD SHOULD YOU PROVIDE YOUR ORCHIDS? • • THERE IS NO ONE ANSWER. IT DEPENDS ON THE PARTICULAR ORCHID YOU ARE GROWING AND ITS CULTURAL REQUIREMENTS. CONTINUOUS ARTIFICIAL LIGHTING (24 HOUR) IS NOT RECOMMENDED FOR ORCHIDS. THEY REQUIRE AT LEAST A 6 HOUR DARK PERIOD AT EACH 24 HOUR INTERVAL.

LIGHT QUALITY • • • LIGHT CONSISTS OF INDIVIDUAL PARTICLES OF ENERGY CALLED PHOTONS. EACH PHOTON WITHIN THE VISIBLE LIGHT SPECTRUM HAS THE POTENTIAL TO DRIVE PHOTOSYNTHESIS. LIGHT QUALITY REFERS TO THE SPECTRAL DISTRIBUTION OF LIGHT RAYS HITTING THE PLANT.

LIGHT QUALITY • • THE ENERGY OF EACH PHOTON IS DEPENDENT ON ITS WAVELENGTH. FOR EXAMPLE, RED LIGHT HAS A LONG WAVELENGTH BUT LESS ENERGY PER PHOTON; BLUE LIGHT HAS A SHORTER WAVELENGTH BUT MORE ENERGY PER PHOTON. APPROXIMATELY ONE HALF OF THE ENERGY OF THE SUN’S RAYS FALLS WITHIN THE PLANT’S ABILITY TO PRODUCE

LIGHT QUALITY • • • PLANTS HAVE A GREEN PIGMENT CALLED CHLOROPHYLL WHICH ABSORBS THE LIGHT ENERGY AND THEN TRANSFERS THIS ENERGY TO DRIVE PHOTOSYNTHESIS. CHLOROPHYLL MAINLY ABSORBS BLUE AND RED LIGHT. THE REASON LEAVES LOOK GREEN IS THAT GREEN LIGHT IS NOT ABSORBED, BUT RATHER REFLECTED BACK OUT. THAT IS WHY

HOW DOES LIGHT WAVELENGTH AFFECT ORCHIDS? • • • RED LIGHT INFLUENCES STEM ELONGATION AND FLOWERING. BLUE LIGHT INFLUENCES LEAF AND PSEUDOBULB GROWTH ( MOSTLY EVERYTHING EXCEPT THE FLOWER). GREEN, YELLOW, UV, AND INFRA-RED LIGHT DO LITTLE TO INITIATE PHOTOSYNTHESIS.

LIGHT MEASUREMENT TERMINOLOGY • • • FOOTCANDLE: MEASURABLE UNIT OF ILLUMINANCE (BRIGHTNESS) EQUAL TO ONE LUMEN PER SQUARE FOOT. LUMENS: A QUANTITATIVE MEASURE OF THE HUMAN VISUAL RESPONSE TO OPTICAL POWER. IN OTHER WORDS, LUMENS ARE WHAT A LIGHT BULB EMIT. FOOTCANDLES ARE THE MEASUREMENT THAT CAN BE TAKEN WHEN THE “LUMENS” STRIKE A PLANT SURFACE.

DIFFERENT TYPES OF LIGHT BULBS • • • INCANDESCENT: A BULB WHICH PRODUCES LIGHT BY THE ELECTRICAL HEATING OF A MATERIAL (INCANDESCENCE). THESE BULBS PRODUCE HEAT AND CONSUME WATTAGE. FLUORESCENT: A BULB WHICH PRODUCES LIGHT BY ELECTRICALLY CHARGING GASFILLED TUBES. THESE BULBS PRODUCE LITTLE HEAT, NEED LITTLE WATTAGE, BUT EMIT RELATIVELY WEAK LUMENS. HID: HIGH INTENSITY DISCHARGE: BULBS

laminate of special chemistry which emits light in response to passing electrons. Different chemistry/filters produce different colors. Today’s LEDs are complex, multilayered A Light Emitting Diode (LED) is conceptually a laminate of special chemistry which emits micro-structures. light in response to passing electrons. Different chemistry/filters produce different colors. Today’s LEDs are complex, multilayered micro-structures.

Low heat (without requiring the usual electrically heated filament to bring the elements to heated incandescence) 410 times more usable light per watt Longer life- 5 -11 times longerto plant usable Light produced can be limited life (50, 000 -70, 000 hours vs. 5, 000 + hours) spectrums Low heat (without requiring the usual electrically heated filament to bring the elements to heated incandescence) 410 times more usable light per watt Longer life- 5 -11 times longer life (50, 000 -70, 000 hours vs. 5, 000 + hours)

watts red and blue LEDs approx (15% of total HPS) watts of used for east facing lean to greenhouse with Odont/Masd growing temperatures and intermediate for Minicats and others. Replace existing supplemental HPS lights in Run lightsand hours/day with photo cutoff both cool 15 intermediate sections with 500 during bright sun. LEDs approx (15% of total watts red and blue HPS) watts of used for east facing lean to greenhouse with Odont/Masd growing temperatures and intermediate for Minicats and others. Run lights 15 hours/day with photo cutoff during bright sun.

Experiment Click to edit the outline text format Second Outline Level Third Outline Level Fourth Outline Level Fifth Outline

Saved 1000 Kwhrs/month lights and AC cooling for 6 months/year. About half that in the winter. About a 5 year payout with LEDs as purchased. Today LEDs Kwhrs/month lights and AC Saved 1000 are more powerful and affordable. cooling for 6 months/year. About half that in the winter. About a 5 year payout with LEDs as purchased. Today LEDs are more powerful and affordable.

Most Odonts have multiple leads and about half of those with multiple full size mature spikes in contrast to previous growing producing only single leads and spike. Click to edit the outline text format Second Outline Level Third Outline Level Fourth Outline Level Fifth Oda. Lavender Lace x Aviewood Outline

Results Increasing percent of plants with super sized pseudobulbs and multiple leads.

tips (awkward watering) Possible unexpected negative or positivethree Odonts out of approx 20 in spike have apical spike from top of pseudobulb in Beginning to get good seedling growth when contrast with previous experience of one of under bench lights are within inches of leaf about 200 in 30 years. tips (awkward watering) Possible unexpected negative or positivethree Odonts out of approx 20 in spike have apical spike from top of pseudobulb in contrast with previous experience of one of about 200 in 30 years.

Intermediate side results are good but not quite so obvious

Pot. Free Spirit ‘Amy’ AM 4 leads open 3 more hidden

Blc. Precious Stones Multiple leads 4” pot

Hknsa. Keepsake ‘Denver Gold’ AM

Results Plants do take on a different color at night.

2. Red and blue LEDs light supplement combination appears to increase new leads and subsequent flowering and pseudo bulb size 1. LEDs can supplement natural lighting at 3. For basement cool growing and aquarium growing LEDthan other choices and because of lower cost lights appear to be the best choice at this time. advantageous for cool lower heat can very growing. 4. Recent performance/cost improvements are Red and blue LEDs light supplement 2. real over the last two years. combination appears to increase new leads and subsequent flowering and pseudo bulb size 3. For basement cool growing and aquarium growing LED lights appear to be the best choice at this time. 4. Recent performance/cost improvements