Lettuce Handbook

Lighting Configuration and High Intensity Discharge (HID) Lamps

The number and position of the lamps were determined using a specialized lighting configuration computer program.

The photo below shows a high pressure sodium (HPS) lamp and luminaire used for supplemental lighting.  These lamps provide the recommended Photosynthetically Active Radiation (PAR) needed to supplement natural light.  The computer control program records the irradiance and adjusts (on and off) the supplemental lighting system to achieve a predetermined total light level each day.  For the lettuce production the recommended level is 17 moles/m^-2d^-1 day.