Why is this research being done?
Stappers: “The technology for artificially lit cucumber cultivation is actually already there, but there is a lack of knowledge about how to apply this technique more efficiently. In this experiment, we want to include leading horticulturists and show the potential of this way of growing. This is the third winter that we do tests at Botany. Especially this year, we see there is a group of growers who want to be actively involved in this, who are coming to visit the experiment to make progress together. That is important for the success of the trial.”
Erik Stappers, Plant Specialist Horticulture bij Signify
Year-round cultivation is already common for tomatoes, but not yet for cucumbers. Why is that?
Stappers: “There are several reasons for this. First of all, more tomatoes than cucumbers are eaten in Europe. Besides, ten years ago it was already possible to use lit tomato cultivation to make a distinctive product in reach and taste compared to the imported products from Southern Europe.”
Beerens: “That's right. Cucumbers have less diversity in supply and consumption than tomatoes. For a long time, the volume of winter production in the Benelux was too low for trade, so too few cucumber growers dared to grow lit cultivated cucumbers. As a result, supermarkets continued to obtain a larger volume in Southern Europe at a lower price.”
Stappers: “Besides, a cucumber plant is more vulnerable to cultivation than a tomato plant, because it grows and reacts faster. You have to know how to deal with this. It is the biggest challenge for growers. The purchase of LED lighting also requires a large investment from the growers. Several growers are certainly open to lit cultivated cucumber cultivation, but they first need to be convinced of the results. They also need support with the design of their greenhouse and lighting type, substrate type, and biological crop protection strategy. That is why many growers are involved in the trial at Botany.”
Jos Beerens, Business Support Manager (teeltadviseur)bij Grodan
Why are you so enthusiastic about this experiment?
Stappers: “In this trial, we make it possible to compare cucumber crops under LED lighting with a combination of LED and SON-T. This provides a lot of useful knowledge and greatly increases the value of the experiment.”
Beerens: “It gives us important insights into how to use energy in the greenhouse even more efficiently in the future. We also learn, through sensors from Grodan in the substrates, how we can save water even better and optimize the growth of the plants. This allows us to refute the image that lit cultivation in the greenhouse is not energy-efficient and sustainable.”
Can you completely refute this mistrust? What is the effect of lit cucumber cultivation on the environment?
Stappers: “It depends on how you compare this. Of course, cucumber cultivation demands more energy in the winter than in the summer. But if you compare it to the alternative, the cucumber transported from Spain (which is less sustainably and less efficiently grown in more traditional greenhouses), there are many solid arguments for choosing the greenhouse cucumber in the Netherlands. LED lighting is currently twice as efficient compared to traditional SON-T and we will continue to improve this. You will see more and more supermarket chains that are very clearly choosing a locally grown product this winter.”
What is different about the light recipe you use for LED lighting, compared to SON-T?
Stappers: “The big difference with traditional SON-T lamps is that with LED you can separate light and heat. This makes the grower more flexible. If you use this well and know how to fine-tune this, you can grow much more efficiently and precisely.”
Beerens: “With LED you can also use specific colors. For example, red and blue have a direct effect on photosynthesis, while other colors can be added to a certain extent to control other plant processes, such as height, distribution, and flower formation. Signify now applies different light colors to see what specific compositions affect the plant.”
And what is Grodan and its substrate solutions’ role in this?
Beerens: “We supply the substrates for the test and can learn a lot from the effect of the different types of lighting on the root environment of the plants in our substrates. By measuring this effect, we can investigate what the most optimal nutrition and watering strategy is for the grower. And by employing the measurement data from our GroSens sensors in the substrates, we can monitor this continuously, in real-time, in our E-Gro platform and make adjustments where necessary.
The great thing about the horticulture sector and this experiment, for me, is that - despite having been in the sector for thirty-five years - I can still learn something new every day. By analyzing and discussing the data in the trial we can learn the most about our products. At the same time, it is also important that we share as much knowledge as possible with our partners. If we keep everything to ourselves at Grodan, and Signify and the growers do the same, a lot of knowledge is lost. By sharing we can help each other further. I find that very valuable.”
What is the first step a grower must take if they also want to get started with lit cucumber cultivation?
Stappers: “Horticulturalists need to do their research and they should not underestimate the complexity of lit cucumber cultivation. It is not the type of light or the type of stone wool substrate that makes the difference in itself. It is about all factors together: you have to press the right buttons within a limited amount of time.”
Beerens: “It is a huge investment, so make sure that the greenhouse and the surrounding area are also ready. It must fit into the corporate structure, the energy framework must be right, and neighbors must consent. If this is all settled, then things will go fast. We are seeing more and more growers who want to make the transition gradually, especially if the market demand for local cucumbers picks up.”
Lastly, what is something that everyone should know about lit cultivated cucumbers?
Stappers: “The story we have to tell as a sector is that we grow a distinctive product. Product quality, food safety, reliability, and sustainability: in all these areas the lit cultivated cucumber from the Netherlands is unique compared to an alternative that is grown in Spain, for example.
Beerens: “And they taste good and fresh. But what I like most is that we can achieve maximum production and quality with minimum liters of water and minimum energy consumption. That is exactly why we are up for this challenge; so that within ten years we will eat more lit cultivated cucumbers in winter than unlit ones.”
About the test
The experiment of lit cultivated cucumber cultivation was set up in October 2020 at Botany and will run until the end of March 2021. Ten parties are currently involved in the trial, including Grodan and Signify.
Read more about Botany
View the first results of the experiment in 2019 here
This article is part of the Gro-Hacks series, in which we ask partners and friends of Grodan what we can learn from their innovative entrepreneurial stories.