What is the best spectrum

Different plants utilized different parts of the spectrum. Factors that are imprtant:

  • Chlorophyll and photosynthesis active chemicals distribution
  • Growth phase
  • Day/night cycle
  • Enviromenthal factors such as temperature, humidity, dust?, water saturation?, ...
  • Light shadows from adjacent leafs, LED light beam shape
  • LED wear out
  • ....

In a many applications the LED array is already given, and it can be very interesting to optimize the channel power distribution for the given array / properties

Photosynthetically active radiation (PAR) - a measure of the light energy that is used in photosynthesis

  • Photosynthetic photon flux (PPF) values all photons from 400 to 700 nm equally
  • Yield photon flux (YPF) weights photons in the range from 360 to 760 nm based on plant's photosynthetic response
1:6 - Lecture