Greenhouse Lighting: Bright Lights, Big Produce


[Light, soft electronic music fades in.] Narrator: Canadian winters can be long and dark. This lack of year-round natural light impedes greenhouse production… …during the winter months. As a result greenhouse growers need to use supplementary lighting to provide the high quality produce… …that consumers want year-round. But not all light is created equal… …and crops develop and grow differently when they are supplied with alternative light sources. Greenhouses currently use High Pressure Sodium, or HPS lights. They have a low capital cost, but you can’t adjust the quality of the light. And they can get very hot – up to 300 degrees… …which means that plants could burn if the lights are too close. Light Emitting Diodes, or LED lights, are a new state-of-the-art technology. They provide higher quality light with customizable intensity, direction, and colour settings. They also have a lower surface temperature than HPS lights… …so they can be used right inside the crop canopy. Agriculture and Agri-Food Canada scientists, Dr. Xiuming Hao… …from the Harrow Research and Development Centre… …and Dr. Rong Cao from the Guelph Research and Development Centre… …are busy a new hybrid lighting system that uses… …HPS lights above the crop canopy… …and LED lighting inside the crop canopy. Agriculture and Agri-Food Canada is one of the leading organizations… …in the world in the study of vertical lighting distribution for greenhouses. The results show that this new system can improve… …the yield and nutritional value of greenhouse crops. They’ve found that by using an optimized hybrid lighting system… …that can deliver proper spectrums of light at different heights… …mini-cucumber plants yield twice as many vegetables as they would in a traditional greenhouse. Twenty times more than they would in the field! They’re also studying the effect of different coloured LED lights… …on the production of antioxidants in greenhouse vegetables. Blue lights increase polyphenols that help plants to protect themselves from insects and disease. Red lights, on the other hand, increase carotenoids and are very good for plant growth and leaf health. The results of these studies may allow Canada’s greenhouse growers to conquer Canadian winters… …and move to full 12-month production cycles. This will allow them to produce fresh vegetables throughout the winter months… …meeting consumer demands for high quality, local produce year round. It will also allow them to be more competitive because they will be able to edge out… …imports during the winter months and will be able to expand their presence on the international market. With the help of our Canadian agricultural scientists… …the sun will never stop shining on Canadian greenhouse growers. And in the right light, at the right time, everything is extraordinary. [Light, soft electronic music fades out.]