Rapid improvements in light emitting diode (LED) technology have resulted in new opportunities for plant growth applications. While High-Pressure Sodium (HPS) is still the most common lamp type used for supplemental lighting (i.e., to boost plant growth), the ever increasing efficiencies of LEDs have resulted in a lot of interest, research and some trials into novel horticultural applications. LEDs allow for adjustments in spectral quality of the light provided, and these adjustments can be made as needed during the entire growth cycle and could potentially improve overall energy efficiency. LEDs produce a lot less radiant heat (instead they generate convective heat), allowing them to be placed closer to the plant leaves without causing heat stress. The phase-out of incandescent lamps has also resulted in more LED applications for photoperiod lighting (i.e., to induce flowering responses). This presentation will cover LED developments and some of the current research into horticultural applications. 

A.J. Both received his Ph.D. in agricultural engineering from Cornell University before accepting a faculty appointment at Rutgers University. His research and Extension outreach have focused on controlled environment plant production systems, including greenhouses, growth chambers, and high tunnels. More recently, he got involved in projects investigating energy conservation and alternative energy sources for greenhouse production. He regularly contributes engineering-related articles to the greenhouse industry trade press.