In this video, Dr. Bruce Bugbee summarizes the dual effects of photon quality on photosynthesis and plant shape. Spectral quality has an enormous effect on shape, but the effect varies among species. Conversely, the effect of spectral quality on photosynthesis is nearly constant among species, but our definition of photosynthetic photons may need revision to include both far-red photons and UV photons between 360 and 400 nm.
2:48 The nine cardinal parameters that affect plant growth
3:59 Summary of spectral effects: 30 years of Bruce’s photobiology research on 1 slide.
8:31 How colors of light penetrate leaves
9:36 Efficiency of LEDs
13:00 Spectral Effects: blue photon fraction and yield of cannabis
16:54 Edges of photosynthetic radiation. Why our definition of photosynthetic photons may need a revision by adding far-red and UV. How our definition of photosynthetic photons is influenced by the Emmerson enhancement effect and the McCree curve.