The 2012 ASHS Annual Conference

Optimal year-round production of greenhouse-grown tomatoes requires the use of supplemental light to complement natural solar radiation in light-limited environments. Electric lighting accounts for a significant percentage of total greenhouse energy costs. Thus, a greenhouse tomato-production experiment was conducted from winter to summer to compare growth, yield, and fruit biomass production per kW-h of energy consumed for two tomato cultivars grown with no supplemental lighting, under overhead high-pressure sodium (HPS) lamps, or with intracanopy LEDs (95% red and 5% blue). An increasing solar daily light integral (DLI) occurred naturally for all treatments, and a constant DLI of 9 mol·m^-2·day^-1 was provided to the HPS and LEDs treatments. Results from this experiment will be presented. This project is supported in part by NIFA SCRI grant 2010-51181-21369.