Abstract: Disclosed is a lighting device for use in the control of a plant disease, which has a light source capable of emitting light containing ultraviolet ray. The light source can emit both of UV-B having a wavelength component with a wavelength of about 280 to 340 um and UV-C in which a wavelength component with a wavelength of about 255 nm or less is cut off from wavelength components with wavelengths of about 100 to 280 nm to plant in a superimposed manner. The irradiation of a plant with the UV-C and the UV-B ensures to further inhibit the spore formation or the hypha growth of a filamentous fungus that causes a disease or the like, and to induce a resistance against a disease in the plant.

Abstract: Disclosed is a lighting device for use in the control of a plant disease, which has a light source capable of emitting light containing ultraviolet ray. The light source can emit both of UV-B having a wavelength component with a wavelength of about 280 to 340 um and UV-C in which a wavelength component with a wavelength of about 255 nm or less is cut off from wavelength components with wavelengths of about 100 to 280 nm to plant in a superimposed manner. The irradiation of a plant with the UV-C and the UV-B ensures to further inhibit the spore formation or the hypha growth of a filamentous fungus that causes a disease or the like, and to induce a resistance against a disease in the plant.

Abstract: An angled illumination tube is capable of reducing a dark spot behind the reflector, while illuminating the tube uniformly over the length of the tube. The tube is used in combination with a light source providing a light beam and comprises an angled transparent tubular conduit having a first end and a second end on opposite longitudinal ends of the conduit. The conduit has a bend between the first and second longitudinal ends, and is used with the first end receiving the light beam from the light source in order to guide the light beam along the length of the conduit. A reflector is disposed within the bend to reflect the light beam from the first end to direct a reflected light beam towards the second end. The reflector defines an incident light axis along which the light beam is guided to the reflector, and a reflected light axis along which the reflected light beam is directed to said second end.