Tamura Imports is a local lighting distributor that generously donated a series of LED (LCT7) lights used in the lighting trial, along with annual cash support. They are a family-run lighting supply company dedicated to ensuring greenhouse growers have all the information they need before deciding what supplemental lighting option is right for them. Current Prairie Horticulture Inc. is a local family-run farm focused primarily on tilapia production via recirculating aquaculture systems and has begun to include greenhouse production. Current Prairie Horticulture support this project through an annual cash contribution. Vivent SA is a Swiss-based deep-tech SME that provides growers, breeders and other tech companies with actionable information directly from the plants through plant physiology sensors.
Supplemental light is a critical factor in greenhouse crop productivity, especially during winter in the northern hemisphere when Daily Light Integral (DLI) is low. Despite the obvious need for supplemental light, only a relatively small fraction of the greenhouse operators in North America use supplemental light due to the high capital investment and significant operational cost (Torres, 2009; Dorais & Gosselin, 2002). However, growing vegetables in winter using supplemental lights is on the rise in Alberta. While the area under lights for the winter production of cucumbers and tomatoes was around 30 acres in 2017 (Mirza, 2017), recently built greenhouses in Central and Southern Alberta have raised that estimate to over 100 acres in 2022. Greenhouse growers who use supplemental lighting tend to employ High-Intensity Discharge (HID) lamps, such as High-Pressure Sodium (HPS), which are expensive to operate and maintain. Horticultural LED lights have been considered as an alternative to HID lights due to their capacity to produce monochromatic light and their better longevity, less maintenance, and higher power efficiency and food safety. Horticultural LEDs however are considerably more expensive when compared to common industrial lights such as High Bay LEDs and as such are cost prohibitive for most commercial greenhouse growers in Alberta and Canada as a whole. This project will investigate the impact of replacing conventional HID lights with less expensive full spectrum High Bay LED lights, which have already replaced HID lights in most other industrial applications. Through this project, we will identify best practices for supplemental lighting in the production of three of the most popular greenhouse-grown crops in Canada: cucumbers, tomatoes, and peppers. Measures of power consumption, yield, quality, and ROI will be accompanied by data from a sophisticated crop electrophysiology system to track plant stress. Adopting suitable, cost-effective lighting technologies can revolutionize greenhouse farming in Alberta by helping growers achieve high yields and superior crop quality without paying for the increased power consumption often associated with supplemental lighting.
Publications
Alberta Greenhouse Growers Associations (AGGA) Summer 2025 Newsletter pages 12-13 “Illuminating the Future: Lethbridge Polytechnic shares first-year results of greenhouse lighting trials” by Dr. Seyed Hashemi, PhD. AGGA Newsletter Summer 2025
Alberta Greenhouse Growers Associations (AGGA) Winter 2025 Newsletter pages 17-18 "Lighting the way to sustainable cucumber production at Lethbridge Polytechnic" by Dr. Seyed Hashemisardroud, PhD. https://agga.ca/news/
Hashemi, S. M., Kurenda, A., Karatepe, S., & Savidov, N. A. (2025). Balancing Yield and Sustainability: A Comparative Analysis of Supplemental Lighting in Commercial-Scale Cucumber Cultivation. Horticulturae, 11(1), 79. https://doi.org/10.3390/horticulturae11010079