“Raspberry isn’t the first crop that comes to mind when figuring out which crops to grow indoors,” Andrea Huegler, R&D Engineer and Agronomist at Certhon said. “However, we accepted the challenge and decided to go for it as there are a lot of benefits to growing it in a controlled environment.”
After successfully growing strawberries in the Certhon Innovation Centre (CIC), the company has decided to take on another trial of growing fruits indoors. Certhon has been doing lots of research on indoor farming for a long time now. This has allowed them to investigate how to grow more complex crops in a controlled environment without daylight.
The main advantage of growing this crop indoors is having higher yields and consistent quality year-round. Certhon sees great opportunities ahead for the crop, due to its premium status and short shelf life. “It makes it a perfect candidate to be grown indoors.” During this trial, common raspberry cultivars were chosen. Certhon used chilled raspberry canes from a propagator, pollination by bumblebees and top and interlighting was used to flourish the crops. The harvesting period comprises 10 weeks, out of a total cultivation cycle of 21 weeks and is expected to end in July 2021.
The research was mainly about investigating the right transition of the vegetative state of the crop to the generative state. Andrea says that balancing the climate and light with energy consumption is the trickiest part here. “Ever since the first raspberry trial we’ve been trying to balance out the reduction of energy use, having an X amount of yield at a great quality and extending the harvesting period. Throughout the trials, we have obtained nearly twice as much yield compared to the traditional Dutch polytunnel producers in the summer,” Andrea notes.
However, raspberry cultivation isn’t without challenges. “One of the risks that could come up is growing grey mold,” explains Andrea. “If nectar isn’t removed well from the flower, the fruit can grow mold or have a grey undertone. However, if you manage your humidity wisely, the incidence is severely reduced. That’s the idea behind the CIC, optimizing growing recipes and eventually expanding the product portfolio because we want to provide a wide selection of product options to our clients.”
The knowledge that is generated in the CIC can also be applied to the cultivation of raspberries in greenhouses. Growing these crops indoors allows Certhon to generate ideal growing conditions and maximum potential for raspberry cultivation. With this knowledge, Certhon generates a blueprint that growers can follow in greenhouse cultivation as well.
Andrea explains, “For instance, the blueprint can be followed when growers want to know when to: provide extra lighting, shading, or adjust the humidity. In this way, ideal growing conditions can be mimicked to achieve the highest quality and yield possible in a greenhouse.”
Another, very important aspect is the quality of the raspberry canes. In order to have good production, your raspberry canes need to be of good quality and pest-free. “This cannot always be guaranteed, '' says Andrea, “since they are propagated outdoors and therefore bound to the pressures of external influences, such as climate. Although we have not tried it ourselves yet, we think the next step is to also propagate raspberry canes in a controlled environment without daylight.”