Daytime control
of a supplemental greenhouse lighting system
utilizes a photoelectric cell that can be adjusted
to the desired light level. A rule of thumb is that
the lighting system should be activated when the
sunlight level falls to twice the level provided by the
lights. For example, if the lighting system provides
500 fc at plant level, it would be turned on when
GERMINATION CART
10"
10"
10"
4' - 8"
2' - 0"
Seedling
Flats
4' - 2" tube
Fluorescent Strip Fixtures
with cool white tubes
Use Heating Tape or Agritape on Bottom
Shelf. Make provisions for Temperature
Control. Enclose sides with white polyethylene
film to retain heat and reflect light.
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the sunlight level falls to 1,000 fc. Often a one- or
two-minute time delay is installed in the system to
prevent the activation of the lights when the sun is
covered by a cloud. Computer control of lighting
is also possible.