WHEN REDS & BLUES COLLIDE
“Understanding how to tilt
the balance towards either
red or blue at key points in
the growth cycle can lead
to important changes in
plant physiology.”
THE COMBINATION
While each color of light has its advantages and
disadvantages when it comes to plant growth, the
overwhelming consensus is that a combination
of blue and red light produces the best results.
Plants grown under a blue-red light source will
have a more typical leaf shape, have more biomass
and experience higher rates of photosynthesis
than plants grown under either color alone.
High-quality LED grow lights will include both
red (640-670 nm) and blue (430-450 nm) LEDs for
maximum plant productivity. Some lights may be
designed to deliver a fixed ratio of red and blue
light, while others allow for control of each color
individually. Manufacturers have even started to
include far-red (730-740 nm) LEDs into their lights.
Understanding how to tilt the balance towards
either red or blue at key points in the growth
cycle can lead to important changes in plant
physiology. For example, controlling flower production can have dramatically different effects in
the cultivation of different species. Suppressing
flower initiation through blue-red light ratios
is beneficial when growing lettuce, leading to a
longer growth period with larger biomass when
other factors such as temperature or photoperiod
might otherwise trigger bolting. However, earlier
flowering in strawberries may lead to more fruit
produced over a longer period of time.
Photobiology is the study of how light interacts
with living organisms and is a growing field with
new research being published every year. More
information on how individual crops respond
to specific light treatments can be found in
horticultural science publications, many of which
are made available to the public.
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Maximum Yield USA | October 2015