Light source for plant cultivation

A plant cultivation light source, comprising:

• a plurality of light sources configured to be turned on or turned off depending on a selected plant and a growth stage of the selected plant, the light sources comprising a first light source and a second light source;
• and
• a controller operable to turn on the light sources during a light period such that the light sources are operable to emit a light having a spectrum with a plurality of peaks to the selected plant;
• the light period comprising a first period and a second period and the first period preceding or following the second period;
• wherein the controller is operable to adjust the spectrum of the light to:
• provide with the first light source, in the first period, a first pattern having peaks of the light that appear at one or more wavelengths to be used in photosynthesis of the selected plant;
• provide with both the first light source and the second light source, in the second period, a second pattern having peaks of the light that appear at the wavelengths being similar or identical to the wavelengths of the first pattern;
• and
• further provide, in the second period, at least one peak of the light that appears at a wavelength equal to or smaller than about 320 nm;
• wherein during the light period, the second period does not exceed the first period.

A method for operating a light source for plant cultivation, comprising:

• turning on or off a plurality of light sources depending on a selected plant and a growth stage of the selected plant during a light period, the plurality of light sources comprising a first light source and a second light source;
• wherein the light period comprises a first period and a second period and the first period preceding or following the second period;
• controlling, with a controller, the light sources during the light period to emit a light having a spectrum with a plurality of peaks to the selected plant;
• adjusting, with the controller, the spectrum of the light to:
• provide, in the first period, a first pattern having peaks of the light that appear at one or more wavelengths;
• provide, in the second period, a second pattern having peaks of the light that appear at the wavelengths being similar or identical to the wavelengths of the first pattern;
• further provide, in the second period, at least one peak of the light that appears at a wavelength equal to or smaller than about 300 nm;
• and
• alternate the first period and the second period during the light period.