Patent ID: 7774979

Claim:
A process of radiating a plant with limited spectrum ultraviolet light to induce photomorphogenic growth comprising: illuminating a light source to produce light with wavelengths extending between ultraviolet C (UVC) and infrared spectral regions; maximizing ultraviolet B exposure and minimizing UVC exposure to light from said light source by transmitting the light from said light source through a single sheet of borosilicate glass having a thickness of between 1 and 10 millimeters, said single sheet of borosilicate glass being non-transmissive of at least 95% of the UVC and more permissive of remaining spectral regions, wherein said borosilicate glass has a point of inflection wavelength between 280 nanometers and 320 nanometers; and exposing the plant to transmitted light to induce a photomorphogenic response induced by UVB exposure.