Transcript PRINCIPLES OF LIGHT

JANUARY 2011
LIGHT PRISM
WHEN THE SUN’S RAYS HIT A PRISM
THE VISIBLE LIGHT SPECTRUM IS REVEALED
• 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 (CO2)
AND WATER (H2O) INTO SUGARS AND OXYGEN
(O2).
• LIGHT (AS STEVE HELBLING SAYS) IS “FOOD FOR
ORCHIDS”.
• DURATION OF LIGHT IN A 24 HOUR PERIOD IS
KNOWN AS DAYLENGTH OR PHOTOPERIOD.
• 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 LENGTH IN WINTER AND 16 HOURS DAY LENGTH
IN SUMMER).
• 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.
• 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 ORCHID TO GROW AND THRIVE.
• SUNLIGHT (IN TOTAL OR IN PART) IS THE FIRST CHOICE
FOR GROWING OPTIMALLY.
• 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 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.
• 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 PHOTOSYNTHESIS. THIS OCCURS MAINLY
IN THE VISIBLE SPECTRUM OF LIGHT. THE REMAINING
AMOUNTS ARE NON-VISIBLE SHORTER
WAVELENGTHS SUCH AS UV LIGHT, OR LONGER
WAVELENGTHS SUCH AS INFRA-RED RADIATION.
• 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 YOU SEE
LEAVES AS GREEN.
• 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.
• 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.
• WATTS: A PHYSICAL UNIT OF POWER OR THE FLOW OF ENERGY.
• MANY TIMES WHEN YOU BUY A LIGHT BULB, IT WILL BE
COMPARED TO THE STANDARD INCANDESCENT LIGHT BULB. FOR
EXAMPLE: A FOUR FOOT FLUORESCENT BULB MIGHT BE
DESCRIBED AS EMITTING LIGHT EQUAL TO A 40 WATT
INCANDESCENT LIGHT BULB.
• 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 GAS-FILLED TUBES. THESE BULBS PRODUCE LITTLE
HEAT, NEED LITTLE WATTAGE, BUT EMIT RELATIVELY WEAK
LUMENS.
• HID: HIGH INTENSITY DISCHARGE: BULBS INCLUDE MERCURY
VAPOR, HIGH PRESSURE SODIUM, AND METAL HALIDE. THESE
BULBS ARE LONG LASTING, ENERGY EFFICIENT, PRODUCE A LARGE
AMOUNT OF LIGHT, BUT GENERATE A LOT OF HEAT AND
WATTAGE.
• LED: LIGHT EMITTING DIODES: THESE BULBS ARE RELATIVELY
NEW AND HAVE TREMENDOUS POTENTIAL IN ORCHID GROWING.
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A Light Emitting Diode (LED) is conceptually a
laminate of special chemistry which emits
light in response to passing electrons.
Different chemistry/filters produce different
colors.
Today’s LEDs are complex, multilayered
micro-structures.
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Light produced can be limited to plant usable
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)
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Replace existing supplemental HPS lights in
both cool and intermediate sections with 500
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.
Run lights 15 hours/day with photo cutoff
during bright sun.
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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 are more powerful
and affordable.
Oda. Lavender Lace x Aviewood
Increasing percent of plants with super sized
pseudobulbs and multiple leads.
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Beginning to get good seedling growth when
under bench lights are within inches of leaf
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.
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Intermediate side results are good but not
quite so obvious
Plants do take on a different color at night.
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1. LEDs can supplement natural lighting at lower
cost than other choices and because of lower
heat can very advantageous for cool growing.
2. Red and blue LEDs light supplement
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 are
real over the last two years.