In April, strawberry enthusiasts got a glimpse of the newly opened research facilities at Proefcentrum Hoogstraten. However, there is more to see beyond the greenhouses that were showcased. Next month, the complex's climate-controlled cells will be officially opened, and this week, the first plants were placed inside. One cell focuses on researching the cultivation of strawberry plants, while the other is dedicated to production cultivation.
Stef Laurijssen from Proefcentrum Hoogstraten highlights the benefits of controlled growing conditions, saying, "From a research perspective, it's fascinating to be able to cultivate independently of outside weather. While we acknowledge the energy benefits of sunlight, crucial for greenhouse cultivation, exploring growth without daylight can also yield valuable insights applicable to greenhouse farming."
The climate cells are designed to have complete control over light and climate conditions. They feature a high-pressure mist system from MJ-Tech, installed by Light4Food, which helps to reduce temperature. Light management is also crucial; both cells use the CoolGrow Linear lamps from Mechatronix, which are specially developed for use in climate cells. These lamps are fully controllable and dimmable, allowing for the creation of customized light recipes.
Propagation Cell
One of the growing cells is fitted with two towers, each containing six tables, and is currently housing young strawberry plant cuttings. This setup is part of the Interreg Flanders-Netherlands project, PlantGoed, which explores how greenhouses can be utilized throughout the year. "To produce strawberries year-round, it's essential to grow the plants continuously," explains Stef. Flemish and Dutch partners are involved in this research to achieve year-round greenhouse use.
To grow strawberries year-round, it's crucial to be independent of natural light and temperature. June-bearing strawberry plants require a short daylight period to start flowering. However, during spring and summer, days are too long for this process, so flowering induction typically occurs from September onward in outdoor and greenhouse settings. After induction, plants are ready by December and can be stored in cold storage. Yet, the goal is to have fresh plants available in spring and summer without relying on cold storage. By eliminating daylight, the team aims to initiate flowering indoors, allowing for fresh plant growth at any time. Currently, the experiment focuses on cultivating cuttings from mother plants, but there are plans to explore growing from seed in the future.
Gaining Knowledge
The plants currently being grown in the cultivation cell will eventually be moved to a greenhouse. You might wonder why they aren't staying in the other cell. "While that's an option, the PlantGoed project's goal is to start cultivation indoors and then transition to standard greenhouses for production," Stef explains. This approach is intentional because the research aims to be practical and applicable for growers, ensuring that they can easily adopt the methods.
The focus of the production trials in the other climate cell is not just on growing plants but also on understanding more about strawberry plants. Implementing this knowledge is a key objective, as the insights gained are intended to benefit broader strawberry cultivation practices.
Cultivation Systems
In their previous research, different cultivation systems were tested side by side, including standard methods, hoistable gutters, and multi-layer cultivation in greenhouses. These studies revealed that even in winter, variations in light, temperature, and humidity from sunlight were hard to control, leading to issues like fruit deformation and rot on the lower layers. In a climate cell, however, these issues can be addressed due to complete independence from natural light. The current focus is on June-bearing plants and exploring how different lighting strategies affect them. "Without relying on daylight, we can experiment more freely and test extremes — what happens if we significantly increase or decrease the light?" Pollination is another area of interest. For instance, bumblebees are having more trouble emerging from their nests during dark months, and this will be investigated. The production cell's construction was supported by the Flemish government and the European Union (ERDF).
For more information:
Proefcentrum Hoogstraten
www.proefcentrum.be