Plants rely on sunlight for growth and development. Optimizing the light plants receive can be one of the most challenging factors for greenhouse crop production. Seasonal and daily changes to natural light mean growers need to supplement with the right light, in the right place, in the right quantity, at the right time. As with everything, there are pros and cons to supplemental greenhouse lighting strategies. But growers who are able to optimize the supplemental light they provide to plants can eliminate seasonal changes in production cycles, increase crop production, ensure crop consistency and grow quality plants year-round.
There are two key lighting components to consider in a greenhouse environment: the natural seasonal light levels in your facility and the daily light requirements of your crop. Supplemental greenhouse lighting is used to increase light levels at times when natural light is low, such as outside of daylight hours, over the winter season, and on gloomy summer days.
Supplemental lighting is a topic that concerns all greenhouse growers, but what are the pros and cons?
For most crops, there is a linear relationship between the total amount of light your plants receive and their growth. The daily light integral (DLI) is the sum of all photosynthetically active radiation (PAR) received by plants over the course of a 24-hour day. DLI is measured in moles of photons (mols) per square meter per day. Generally, the more photons – or the higher DLI – plants receive, the better the overall quality and production rates of plants.
Many greenhouse growers are choosing LEDs for their supplemental lighting to increase DLI and eliminate seasonal shifts in light. This helps them increase year-round yields and keep production output stable for their customers. Andrew Fuller, Technical Director, at the UK’s Bridge Farm Group, noted:
“Supplemental LED lighting allows us to provide the freshest and most flavourful herbs on the market 365 days a year despite seasonal changes.”
It’s important to note that each plant species has an optimal light intensity above which light absorption and photosynthesis are not as efficient. Your lighting provider should map out a greenhouse lighting plan that considers the needs of all your individual crops.
Intelligent LED lighting and variable spectra controls can deliver the right light intensity (quantity), in the right ratio of wavelengths (quality), tuned to the DLI of your choosing (duration), and focused evenly on your plants (distribution). By harnessing these 4 key light properties, today’s grow facilities are ensuring optimal light exposure for their crops.
There is an upfront cost to adding supplemental greenhouse lighting, as well as the operating costs of running your lights day-to-day. There are, however, a few ways to mitigate those costs.
Generous rebates and incentives are being offered to growers who implement energy-efficient LEDs. These funds are being provided by government and utility organizations to encourage the switch from traditional lighting. They can help drive down the purchase price and considerably shorten your buy-back period. You may be surprised by the size of the rebates and incentives currently on offer. Download our eBook for the United States or Canada to find out what’s available to you.
When it comes to cleaning, our MITRA is IP67 rated and can be quickly hosed down, saving you time and effort, while HPS lamps and reflectors require regular, careful cleaning. Plus, LEDs don’t require bulb, ballast, or driver replacements, further driving down costs and using fewer consumables.
While supplementing the light in your greenhouse is necessary to account for daily and seasonal changes to the sunlight hitting your plants, the right supplemental greenhouse lighting can make all the difference when it comes to uninterrupted, high-quality crop production. Greenbelt Microgreens experienced “an immediate 13% increase in yield” with Heliospectra LEDs, according to their Head Grower, Alice Farris, while keeping “production cycles similar from summer to winter.”
Want to learn more about using supplemental lighting to improve your crops and increase year-round production?
Be the first to know about LED lighting technology and the latest in horticulture. Get monthly updates with our most recent blogs delivered right to your inbox.