4 keys to lighting success

Lighting can be a confusing topic for growers to understand – which is why it’s often best for growers to understand their lighting before improving it.

According to Dr. Abhay Thosar, a senior plant specialist at Philips Lighting, growers often misunderstand how much light is actually being delivered to the crop, how much light is needed and what kind of light to use. Light, Thosar says, is not always properly evaluated by growers when making a lighting change. This makes it difficult for growers to make the right choice for their operation.

But, with planning and with the right tools, it is possible for growers to make an informed decision about their lighting needs, which can make all the difference for growers aiming to improve their operation.

“Each grower is unique in terms of their growing method, what crops are being grown and how crops respond to the growing environment,” Thosar says.

1. Understand your lighting situation.

According to Thosar, there are several factors that impact light levels and how much additional light each crop needs, including type and location of the greenhouse and specific grower objectives.

For instance, a sunnier climate and long days of summer may reduce the need for supplemental light. However, the delivery of light to the crop can be reduced by a not-so-clean greenhouse, even in the sunniest of locations. And growers should not just assume that sunny weather provides enough light, Thosar says.

Additionally, Philips can help start the process of evaluating lighting needs. A Philips technician can measure light for a grower and then show them what their next steps could be. And if a grower wants to start an LED trial to provide supplemental lighting, Philips can help by organizing a small trial. A small trial can help a grower evaluate LEDs before determining if a larger LED trial is necessary.

2. Learn, grow, scale.

In last year’s State of Lighting survey, 43 percent of growers said they consider themselves an “early adopter” of technology – meaning they are willing to try new technology, but need to see proof that it works first. Another 30 percent of responded said they’ll try a new technology, but only after it’s been used by their peers.

Additionally, 36 percent of growers say that they are considering installing, expanding and/or replacing supplemental lighting within the next three years. These combined statistics tell us that, within the industry, growers are looking to expand or improve their lighting – all they need is some proof.

This falls in line with the approach Thosar recommends growers take. By seeing what growers in similar environments and growing similar crops are doing, it can help inform a grower’s decision to begin a trial and consider an expansion. And by seeing that data, Thosar says, growers can see how LEDs may benefit their expansion and that it’s not as complex as they may have thought.

3. Determine lighting requirements using optimal Daily Light Integral (DLI) and light meter data.

In addition to identifying the amount of light your crops are receiving (this is done by properly and accurately measuring light), it is important to know the light requirements of your crops. According to Thosar, generally an optimal DLI for propagation of annual or perennial plugs is between 10-12 moles; for tomatoes, the optimal DLI is 20-24 moles. This may change based on cultivar as well as stage of growth.

According to Thosar, a grower can take the DLI they’ve calculated from a light meter measurement and subtract it from the known optimal DLI level for that crop, to then determine their approximate lighting deficiency. Philips can then help determine what supplemental light is actually needed. From there, trials are the best avenue for collecting more data about light. Additionally, growers should know that crop inputs may change when lighting levels change. Therefore, it is smart to start with a smaller trial before expanding or committing significant resources to new bulbs and fixtures.

A Philips Lighting representative can assess your lighting needs and determine if your operation can benefit from a new lighting strategy. Get in touch and learn more here.

4. Determine your ideal lighting periods.

In addition to how much light is needed, the length of time a plant should be under supplemental light each day is an important decision for growers. According to Thosar, the answer is not in a one-size-fits-all approach. Determining an appropriate light period involves considering the climate, time of year and crop being grown. This is something that can be determined in trials and adjusted as lighting needs change.

“For certain crops, you cannot give them more than a certain number of hours,” Thosar says, adding that if growers are growing the same crops, lighting periods can stay constant. But if a grower changes what they are producing, then lighting periods and light needs must be evaluated and adjusted.

That’s why it’s important to be precise, Thosar says, and it’s an avoidable mistake he says growers make far too often.

“I see this all the time with growers,” Thosar says. “They say ‘I have a lot of light, but I’m having issues with my growing.’ They can’t know what the solution is without finding the optimal lighting condition. They need to see that comparison for themselves.”

Photo courtesy of Philips