Pilot Project: LED Supplementary Light to Sunlight on Cucumber and Tomatoes at Agriville Greenhouses in Leamington, ON.
The purpose of the LED Spectra Blade arrangement at the Agriville Greenhouse was to understand the potential for energy savings in a large-scale production growing tall plants: cucumber and tomato. The traditional supplemental approach, 1000W HPS lamps, were compared to predominately red and blue LED overhead replacement lamps while Intravision supplied an inner-canopy LED light system comprised of two different light spectra based on our research with the University of Guelph’s Controlled Environment Systems Research Facility.
The objective targets for the study:
Overall energy reduction of 50% or more compared to using a standard 1000W HPS lamp.
Test the Spectra Blade inner-canopy light system as an alternative approach to overhead lighting systems.
Test two alternative LED light spectrums:
Dominant red and blue spectrum with far red
Sun-like white/green spectrum
The discovery on tomato…
When comparing an Intravision red and blue dominant LED approach inner-canopy versus competing red and blue dominate LED overhead approaches the advantage favours inner-canopy but only from an electrical efficiency point of view. Biologically both approaches are sub-optimal. Red and blue inner-canopy has limitations as a supplemental approach because the spectrum is not tailored to the environment and overhead LED approaches are a failure in both respects. Energy efficiency and spectral limitation.
When comparing an Intravision white/green dominate LED approach the story is more compelling. The real challenge for LEDs as a supplemental greenhouse lighting solution is proving LED can compete against HID lighting biologically while saving energy. So what happened when Intravision applied our controlled environment know-how?
The 1000W HPS and Spectra Blade on 50% less energy, proved equal in flower productivity towards the mini-cluster: Avalantino. However, the morphological development of the fruit at the height of the vines was retarded on the inner-canopy treatment. Due to less heat projected from the LED’s the temperature on the plants within the Spectra Blade zones were 5 degrees C lower compared to the HPS control. Therefore, the inner-canopy approach proved equal to the task at delivering the right light on half the energy but without adjusting the temperature to accommodate the efficiency of LED the true potential of the Intravision approach is as of today, unknown in the greenhouse sector.