If you’re thinking about taking the first step with LEDs, the process can seem daunting. There are so many claims and so much information being shared that you may find it difficult to wade through the information with confidence and true understanding.
The reality is that LED technology is here, and regardless of the crops you grow, it’s time to begin seriously thinking about and preparing for the eventual transition to LEDs that will take place in your greenhouse operation.
You can begin the transition by starting with a small trial area in your greenhouse operation. As with other processes in the greenhouse, it isn’t quite as intimidating when broken down into smaller, more manageable steps. Follow these five steps to set up this trial area.
Step 1: Identify your challenge.
Some crops have higher values, meaning they generate more revenue or higher margins, than others. It could be that there is a high demand for a specific crop or that a crop brings in higher margins but presents some unique challenges when growing. Consider the following factors when selecting the crop/cultivar for your trial:
- Production volume
- Economics of production
- Propagation challenges
Step 2: Determine a location to set up your trial.
Select a location in your greenhouse, ideally in a typical growing area. To get an appropriate sample size and maintain environmental conditions, it is recommended that the trial area for plug trays be approximately 1,000 to 1,500 square feet. If you’re conducting a lighting trial over potted plants, a larger space may be required.
Step 3. Set up comparative lighting scenarios.
You’ll want to work with a lighting supplier to determine the best way to set up a trial that allows you to compare your current lighting situation to a new lighting scenario.
Start by measuring the inside light levels of your current lighting and compare them to the daily light integral (DLI) for optimal growth of the crop being grown in the trial. This will help you determine if part of the lighting trial is to track the results of delivering increased light levels, or if the trial is to see the results of growing under a different spectrum. You want to see the effect of more light as well as understand the crop response to the focused red and blue spectrum of LEDs.
76% of growers growing under LEDs agree that LEDs have improved the quality of crops at their location
Step 4. Track the results.
Plan to track the data to not only document the effect on crop growth but also to understand how other crop inputs are affected by the LED lighting. Note adjustments that are made. It is recommended that measurements or data be recorded once a week. (See chart.) Be sure to have the same person measure and record the data at the same time every week during the trial.
Also, take side-by-side photographs of the crops to capture the difference in rooting, basal branching, coloration, speed of flowering, etc.
Step 5. Review the trial results
Let the results inform your decision. Did you see an uptick in the fill rate? Did you note faster flowering? Were you able to decrease the application of PGRs? Once the improvement in crop growth is translated into quantitative and/or qualitative results, you can then calculate the true ROI of an LED installation. This information will help you develop a plan for converting to energy-efficient LED lighting.
Check out this video of John Bonner, owner of Great Lakes Growers, explaining how he conducted a trial to compare and evaluate growing lettuce under HPS to growing under LEDs.