Testing for Success: Best Practice Approach to Running Your Next Lighting Trial

It’s not an over-exaggeration to say that lighting can spell the difference between the success or failure of an indoor farming or greenhouse business. Get your lighting right and you can look forward to bumper yields of high-quality, high value crops with lower energy bills and minimal maintenance. Get it wrong and you risk throwing away good money after bad, with higher energy bills, frequent maintenance and a larger carbon footprint for a potentially smaller, lower-quality yield.

Of course, you can’t always plan for every eventuality (although you can arm yourself with the right questions to ask your lighting partner) but a well-planned, well-executed trial can certainly go a long way towards mitigating the risks of upgrading or transforming your lighting set-up. With over a decade of experience supporting a variety of customers in Controlled Environment Agriculture (CEA), Current has developed a sure-fire, best practice approach to getting horticultural lighting trials right, to ensure long-term, sustainable growth and success of your greenhouse or indoor farming business.

Where to start?

Whether you’re considering a retrofit from high-pressure sodium (HPS) lighting to low-energy LEDs or simply upgrading an existing LED installation, it’s important to recognise that any successful trial will require a commitment, both from the lighting partner and the business owner. It’s important to plan accordingly in order to secure the best possible return on any investment of time and capital. It’s also important to consider the trial from both an operational and a plant science perspective to find the most suitable lighting solution for the business, and by taking a methodical approach, together we can identify the best way forward, based on clear, data-driven insight.

There are three key stages to any trial: pre-trial planning and preparation, monitoring once the trial is underway, and post-trial evaluation.

1. Pre-trial planning and preparation

This is the most important phase of any trial. At this point, we will establish your trial objectives, design the trial to meet those objectives, establish the trial area and design the optimal equipment and lighting plan to conduct the trial effectively.

Establish a baseline

It seems obvious but the first step is to formally identify our starting point. Different types of crops require different environmental conditions to thrive so it’s helpful to outline the type of crop to be grown. This will also determine a realistic duration for the trial. For example, with tomatoes, a typical trial length may be nine to ten months, whereas with leafy greens or lettuce, the trial could be completed in approximately four to eight weeks. We can also use the crop density (or number of plants expected per square metre) to inform the most appropriate lighting fixture for your trial.

Then, we will establish the baseline for comparison with your existing lighting set-up, identifying the current supplemental lighting model, light spectrum, intensity, photoperiod and more. Finally, we will agree exactly what elements will be compared during the trial. For example, we could compare the effects of different levels of supplemental light intensity, varying photoperiods or alternative light spectrums to produce the maximum yield whilst maintaining or increasing quality. By being clear about which variable will change, we can focus on keeping the other variables constant so as not to skew the results and misinterpret the outcome.

Trial design

Once the objectives are set and agreed, we can then design the specifics of the trial. To ensure the findings of the trial are representative of the wider facility, the more plants that can be included in a trial, the better. We tend to recommend 1 bay at 15m (49 feet) long but considering the importance of the trial in determining the future potential of the business, we’d always advise dedicating as large an area as possible!

At this point, the trial duration will be calculated, based on the number of crop cycles to be included and the typical duration of each crop cycle. Many trials commence in late Autumn, as with the onset of shorter, colder days, there is a greater need for artificial lighting to supplement natural daylight and enhance photosynthesis, thereby improving the growth and quality of plants in greenhouses.

What are the results that matter to you?

Every operation is unique and due to regional consumer trends and preferences, the objectives of one business can be very different from another, even when growing the same crop. Therefore, understanding and measuring the desired plant morphology will be important in evaluating the success of any trial. Some growers prefer to measure either fresh or dry plant mass, leaf area or the overall size of the plants. Others may have very specific criteria to their operation which can also be added to the measurement plan. These could include for example, the best possible taste and texture, or a longer shelf life. Whatever your criteria, it’s best to establish these up front.

Setting up your trial space

When it comes to the physical set-up of the trial, it’s important to try and map your trial area as closely as possible to your production area, preventing any “experimental noise” from encroaching and potentially generating findings that aren’t a result of the lighting treatment tested. As we need to ensure that other climate variables such as temperature, humidity and CO2 levels are maintained within desired levels, we also need to install the right environmental monitoring equipment to alert growers to any changes within the trial space or differences between the trial and main production area. Current’s Daintree Horticulture lighting control and environmental monitoring system is one such solution; a secure, wireless system of sensors and controllers that allow growers precise oversight and real-time control over their growing areas. Alternatively, they may already have a preferred system in place.

When growers are exploring more significant operational transformations, such as a transition from HPS to LED lighting, we typically work very closely with them to mitigate the impact of the technology change on other non-light-related factors. For example, in colder climates, energy-hungry HPS lighting generates a high level of radiant heat alongside the light that is useful to the plants for photosynthesis and growth. Therefore, growers may need to consider alternative heating methods which are typically much more energy efficient than the radiant heat from HPS lamps. Often, growers who are unsure about whether they are ready to transition to a new technology also benefit from seeing exactly how much energy can be saved by moving from HPS to LED. Therefore, we will also typically fit an energy meter to demonstrate the potential financial savings associated with horticulture LEDs and the results can be eye-opening!

2. While the trial is running

A robust and detailed plan has been established, the equipment has been installed, and the plants are ready so now the real work can start! For growers and partners to get the full benefit of any trial and ensure that the results are of genuine benefit to the business, it’s important to monitor the trial on a daily basis, taking detailed notes and photos of the plants’ growth and development. You should also record environmental data and key milestones, such as changes in growth stage. By keeping on top of the trial on a daily basis, any unexpected issues or trends can be caught and fixed early, ensuring that no time or effort is wasted and the best possible lighting solution is found to match your objective.

Sometimes this data capture can be overwhelming so it’s a good idea to set up templates and procedures to make the recording process as seamless as possible.

3. Post-trial analysis and next steps

Once the trial is complete, it’s time to analyse the data collected and refer back to the original trial objectives to see if the findings answer the most important questions posed. Take time to review any outlying data points and see if they could be caused by other factors (e.g. external influences or equipment malfunction) and assemble your conclusions based on the data and observations made throughout the trial period.

With you, every step of the way

When working on trials with customers, our lighting experts and plant scientists are on hand to support every step of the way, helping to design the most effective trial for the individual grower, offering support and insight during the trial execution stage and finally working on next steps with the client once the results are in.

By taking a more robust, data-driven approach to lighting trials, we can reduce the risk and uncertainty often associated with such significant equipment upgrades, offering growers greater peace of mind and confidence in the advantages that their future lighting will bring.

Are you ready to start planning your next lighting trial? Get in touch with our expert team to discuss your requirements and let us help you plan your path to greater productivity.