Spotlight on strawberry production

Photos courtesy of Signify (formerly Philips Lighting)

Produce Grower: Why is light a key factor in strawberry production?

Amos Bassi: Whether growing strawberries in a greenhouse or indoors, light is a key factor for photosynthesis, playing a crucial role in the plant’s growth and development. Strawberry plants require a significant amount of light to photosynthesize and produce energy for growth. In a greenhouse environment, artificial lighting is often used to supplement natural sunlight to ensure that the plants receive enough light to grow and produce fruit. Additionally, light intensity and duration can affect the timing of flowering and fruiting in strawberry plants, which can impact the overall yield and quality of the crop. Therefore, managing the light environment in a greenhouse is essential to maximize your strawberry production and overall profitability.

PG: What are the radiation levels that growers should target for strawberry production?

AB: The radiation level to target for strawberry production can vary depending on the growth stage of the plants and the specific needs of the cultivar being grown. The optimal daylength for strawberries depends on the type grown. It’s based on the desired light sum per day, which varies between 12 to 16 hours for different types. Light intensities, based on achieving 15 to 18 mol/m2/day (sun + LED), vary between 200 and 300 µmol/m2/s depending on the greenhouse location. We recommend dimmable installations through our GrowWise Control System.

PG: I’m currently growing strawberries under HPS. What are the considerations for switching to LED?

AB: If you are currently growing strawberries under HPS lights and are considering switching to LED lights, there are several factors to consider:

Spectrum: LED lights can be customized to provide a spectrum that is optimized for strawberry growth and development. Look for LED lights that provide a balanced spectrum that includes blue, green, red and optional far red wavelengths. If you choose to have a static spectrum without far red, then we always recommend Philips LED flowering lamps as part of an overall lighting strategy. The location of the greenhouse — latitude and longitude — will ultimately dictate whether far red is required.

Energy efficiency: LED lights are much more energy efficient compared to HPS lights, which means that switching to LED lights can significantly lower your energy costs. By using LEDs, growers can provide a higher light level to their crops while using the same amount of energy. Additionally, the spectrum of the LED can also have a significant impact on the efficiency of the lighting system. Therefore, choosing the appropriate LED spectrum can further enhance energy efficiency.

Heat: HPS lights produce heat — not always a problem in winter, but challenging in autumn/spring. LEDs produce less heat, improving the greenhouse climate. By decoupling two important crop inputs, heat and light, growers have greater control over their greenhouse climate and can more easily manage their crop in all seasons.

Growers should consider the energy costs of providing supplemental lighting and balance the benefits of increased radiation levels with the cost of energy consumption.

Overall, incorporating LED lighting or switching from HPS to LEDs can provide several benefits for strawberry growers, including improved plant growth, higher energy efficiency, and stable, year-round production.