Patent ID: 8338801

Claim:
A lighting system for preventing a plant disease damage, comprising: an ultraviolet light source which emits ultraviolet ray including UV-B in a wavelength region of 255 to 340 nm; a visible light source which emits visible light; and controllers which control a lighting of the ultraviolet light source and the visible light source, wherein one of the controllers controls the lighting of the ultraviolet light source so that a horizontal irradiance on a canopy surface of a plant is 50 μW/cm 2 or less during a predetermined daytime period and an accumulated ultraviolet intensity per day is limited to 10 kJ/m 2 or less, and the other controller controls the lighting of the visible light source so that the horizontal illuminance on a canopy surface of a plant is 10 lux or less during a predetermined nighttime period.