photoperiodism
(Science: biology) Events triggered by duration of illumination or pattern of light/dark cycles: often the wavelength of the illuminating light is important as for example in control of circadian rhythm in plants.
See: phytochromes.
The response by organisms in response to the availability of light in their environment. Photoperiodism plays a part in some organisms biological clock but is primarily related to the way light affects plants flowering and the state of phytochrome.
Dictionary > Photoperiodism
