Abstract: A plant cultivation device and the like capable of growing a plant while preventing leaves thereof from curling are provided. The device includes: a first illumination irradiating the plant to be cultivated with blue light; a second illumination irradiating the plant with red light; and a controller controlling irradiation of the blue light from the first illumination and irradiation of the red light from the second illumination, wherein the controller controls the blue light irradiation to be performed 21 hours or more a day including a case in which the blue light irradiation is performed 5 hours or more without performing the red light irradiation, and the red light irradiation to be performed 12 hours or more a day.

Abstract: The present invention provides a method for cultivating a plant seedling, which can cultivate a seedling causing no spindly growth, having a thick stem, and being favorably grown even after planting. The method for cultivating a plant seedling of the present invention is a method for cultivating a plant seedling by irradiation of a plant seedling with artificial light for promotion of growth, comprising continuously irradiating the plant seedling with blue illumination light for period (A), wherein 30% or more and less than 80% of the time taken for period (A) for continuously irradiating the plant seedling with blue illumination light corresponds to period (A-1) for continuously irradiating the plant seedling with blue illumination light and red illumination light.

Abstract: Provided is a method of culturing green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light. The green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by intermittently radiating a red illumination light while continuously radiating a blue illumination light.

Abstract: Provided is a method of culturing green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light. The green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by alternately and continuously radiating a red illumination light and a blue illumination light.

Abstract: Provided is a method of culturing green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light. The green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by intermittently radiating a blue illumination light while continuously radiating a red illumination light.

Abstract: Provided is a method of promoting the growth of green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light, in which the green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by alternately and continuously radiating a red illumination light and a blue illumination light.

Abstract: Provided is a method of culturing green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light, in which the green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by intermittently radiating a blue illumination light while continuously radiating a red illumination light.

Abstract: Provided is a method of culturing green algae which promotes the growth of the green algae which is in a state of being a green swarm cell by irradiating the green algae that accumulate astaxanthin with an artificial light, in which the green algae are grown in a liquid medium while maintaining a state in which the color of a culture solution of the green algae is green or brown by intermittently radiating a red illumination light while continuously radiating a blue illumination light.