LIGHTING APPROACHES TO IMPROVE GROWTH IN CONTROLLED ENVIRONMENT SYSTEMS

Controlled environment agriculture (CEA) is often used to realize year-round production in the horticultural sector. In CEA systems, supplemental lighting can account for a large percentage of operating costs (15 - 30%). The research aims to decrease production cost and increase profits for growers. Results from our first study indicate that ‘Little Gem’ and ‘Green Salad Bowl’ lettuce tolerate fluctuating light levels, suggesting that regulating supplemental light in response to real-time electricity prices is feasible for CEA. Our results in the far-red lighting study indicate that lettuce biomass and size increase as the amount of supplemental far-red light increases, suggesting supplemental far-red is effective in CEA. The lack of far-red effects on LsXTH8 expression indicate that other genes may play a role in the leaf expansion effects seen under far-red light. More research is needed to determine which cell wall loosening or cell division genes are involved.