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Komkommerteler kiest tóch voor LED: “Dit lijkt op wat jij in je hoofd hebt”

“Just walk on, turn right and then through that corridor.” The sound of sorting cucumbers can be heard in the background. We enter the office and meet growers André and Kees Vahl at the main location in IJsselmuiden.

When we are having a cup of coffee, Dries also walks by. The three of them form the management of the cucumber nursery, which also has an organic cultivation location for tomatoes and peppers a little further along and a branch in Germany.

It is mid-April, cultivation is in full swing everywhere. Not much later, Leo Lansbergen from Fluence joins and, just back from a visit to growers in the United Kingdom, Barend Löbker from Vortus also joins. This completes the 'team' behind the choice of cucumber growers to opt for LED lighting after all.

In the context of Vortus' 40th anniversary, we wrote the story below, which also appeared in Vortus' anniversary magazine .

Barend, Kees and Leo

In the autumn of 2019, Barend and Leo sat down with grower Kees for the first time. How did that happen?
Barend: “In October 2019 I was allowed to speak in Austin, USA, at the PHOTOx Summit organized by Fluence. I was asked to tell about my experiences with lit cultivation. I did this together with Ep Heuvelink of Wageningen University & Research. The university conducted trials with full LED lighting in cucumbers. I had followed those tests. At the event I ran into Leo. He really just joined Fluence.”

Leo: “That's right, it was literally my first week. We got talking. The event was all about full spectrum LED lighting. Barend already knew that from tests, he said.

Barend: “It was at the WUR in Wageningen that year that I first saw cucumbers grow normally under LED lighting. That had never really worked out until then. At least I hadn't seen it yet. With full LED it worked in that test.”

At the time, the Vahl brothers had also been working on their own experiments with lighting for some time. HPS fixtures were already installed in part of their greenhouse. Trials with LED lighting had also already been carried out. Didn't like them?
Kees: “In our cucumber cultivation we have tested with LED lighting several times. Each time with a red-blue spectrum. We didn't like that every time. As a result of those tests, we had already written off LED in cucumber. Until Barend called. He said: 'Kees, I have now seen something that you should give it another chance. This looks like what you have in mind.' Then I called Leo anyway.”

Barend: “I had barely left the house when I called Kees.”

The result was not much later, so a first conversation. Wasn't that very fast?
Leo: “Yes, sure! Fortunately, it turned out that both Vahl and Vortus were eager to share knowledge. Like us. Moreover, we all proved willing to feed each other with information. I think it is a good example of how the entire ecosystem comes together.”

Barend: “Both Leo and I are cultivation technical people. This allows us to spar well together, also together with Kees. We both took a piece of knowledge with us to IJsselmuiden, but it is Kees who, together with André and Dries, ultimately makes the choice. They are at the controls.”

Keith nods. “For us, the crop advisor is someone who provides information. Someone with whom you can consult, without the cultivation advisor forcing the grower's way of growing. Ultimately, we must bear the responsibility. As a grower you make many decisions every day. It's nice to get good advice.”

Leo agrees. “Before I started working at Fluence as a service specialist, I worked for a breeding company and before that as a crop consultant. From that time I know how important communication is. I think it is just as important for an information officer or adviser to use your ears as your mouth.”

Together, the men agreed to start a trial on 2000 square meters. But then it was already winter. Wasn't it already too late?
Leo: “No, but there was some urgency to take part in the last part of the darkest four months in the test. It was planted on January 2. On February 3, the lights were switched on in a greenhouse in which as much as possible could be controlled separately. A separate heating compartment, separate aeration and watering came in handy for this. It was not possible to administer CO2 separately and measure EC.”

Barend : “The trial really started learning how to grow with full LED. In Kees' greenhouse we learned what we could do with the lamps. Until then, I had mainly seen it at WUR.”

Leo: “We registered a lot from the start.”

Barend: “First, standard planting was done. After just one week, however, we already saw that a stem was needed. The plants grew so fast. I had already heard about this from colleague Tineke (Goebertus ed.) of Vortus from Canada. At the same time, she was running a comparable test, also in terms of design, with full LED. Fluence was also there. Leo didn't even know that when we first sat down at the table. I was able to spar well with Tineke, just like with Kees and Leo. We saw a lot of the same things happen. One of the conclusions we drew was that you needed a single plant in a full LED-lit crop. Not a topped plant. Such a lamp produces so much energy that the foundation, the plant, has to be very strong to be able to convert all the energy into cucumbers.”

Kees: “For us, that test was necessary in order to dare to scale up. Full LED in cucumber was something new that we didn't just want to go for tests at test stations. We really wanted to see it with our own eyes in our own greenhouse. When that turned out to be going well, we went for 2.1 hectares.”

What makes this full LED cucumber cultivation so special?
Leo: “Based on sound trial results in good cooperation with information officer, grower and LED supplier, this became the first cucumber crop of the long type to be grown under full top LED in the Netherlands. What is very special is that the Vahl brothers have switched from an unlit cultivation to fully LED.”

Barend: “It was a risk for us to say, once things were going well in cultivation at Vahl: 'Full LED from Fluence is good.' We like to remain independent as a consultancy. On the other hand, we also believe that if something is good, you should say so. That does not mean that we will no longer be independent. We also serve plant breeders and growers at the same time. The same applies here. Those who have good plants are doing well and if we are asked about it, we will name what is good. The grower always has to choose for himself.”

The latter also applies to the cultivation advisor with whom the grower wants to work, right?
Bernard : “Certainly. It was through then advisor Rien Rodenburg that growers got to know me. I would take over his clients.”

André Vahl , who does computer work in the cafeteria during the conversation, remembers it well.

André, laughing: “At first, Barend did not immediately reach out to all growers when he took over Rien's customers. Some thought he was too young and inexperienced. However, they soon came back to that. Soon he was welcome everywhere, when they saw what he has to offer.”

Kees: “Growing is the same as getting your driver's license. Ultimately, you learn the trade in practice. This also applies to information officers.”

The men come to talk about the shortage on the labor market and the difficulty of finding new, skilled people.
Leo: “When I was still at school, you could easily have sixty people in a horticultural course in an academic year. Now the flush is much thinner.”

Kees nods: “I see it with my daughter at school. There, few opt for horticulture. That also means that fewer new, young information officers are presenting themselves.”

When the men sit around the table, it is not just about cultivation-technical matters. That much is clear. How did Kees end up in Germany as a grower?
Barend : “A German customer of mine was confronted with the sudden death of a manager. The other manager and owner was so shocked that he no longer dared to continue the planned expansion on his own. Just before that, Kees had dropped something along the lines of 'sometimes wanting to look abroad'. That tragic death made me think about that again. I decided to ask Kees.”

Kees : “A day later, after consultation with my wife, I drove in that direction. In the end I was there for 5.5 years. We went to live there. I became a shareholder in the nursery in Bralitz. I still go there regularly, although I now live next to one of our locations here in IJsselmuiden. So it was definitely thanks to Barend that I also started growing in Germany.”

In discussions about the step to LED lighting, the complete picture was extensively examined and discussed. Which topics were reviewed?
Kees : “Prior to the project, we discussed everything and took many things into account in advance. A winter crop with lighting starts with sales. If it isn't there, don't start it. The fact that electricity became very expensive was nevertheless an unforeseen scenario…”

Kees is referring to the energy crisis that has been felt in greenhouse horticulture since last autumn. Nobody escapes it.

Barend: “We are now making the same considerations that we previously made about lighting, but now about energy. You have a lot of variables to take into account. Planting data, the quantity you want to get… You need to have a plan for this, but one that allows you to be flexible afterwards to respond to what is going on. That is the challenge, always.”

You are used to something in horticulture, aren't you?
Kees : “Unfortunately, yes. I also remember the EHEC crisis of 2011 well. Then we had to throw away 1 million cucumbers. Exactly in the period when we were also working on the first drilling for geothermal heat. I will never forget that hectic time.”

Leo: “And in the end it wasn't even the cucumbers. But yes, that only became apparent later.”

Barend , with a sense of understatement: “That cost a lot of money back then.”

Vahl's geothermal energy activities have been mentioned. Vahl got there early.
Kees: "You have to keep developing, don't you?"

Barend: “If father Vahl had not replaced his older greenhouses with higher greenhouses, with fewer loose paths, things would have been very different now. Now there is a modern, innovative company here in IJsselmuiden. It gives the opportunity to illuminate.”

Kees: “Replacing the older greenhouses was a step my father took when it turned out that me and Dries were joining the company. After my father retired, we invested in geothermal energy.”

Leo: “Being innovative and sustainability, that's what this company is all about. I like that."

Kees nods: “We really think like a family business. You hope that the next generation will take over and then you want something good to be written. A second geothermal source is important here. That source has been coming for a long time, but now it's really happening. It took longer than expected.”

In light of the current crisis, followed by: “Actually, we are lucky that we can always sleep.”

Has that never been different?
Barend: “During the time that clavibacter was on the rise in tomatoes, André really had some headaches. It was at the time that Vahl also had tomatoes. In the fall. Autumn tomatoes. This was chosen because of virus pressure in cucumber.”

Kees: “We've had really good years with those autumn tomatoes. The tomatoes fetched good prices in those years. Until the lighted cultivation came along.”

Was tomato new to Vahl at the time?
Kees: “We had always had tomatoes as a hobby. So we knew we could do it.”

Even today, tomato is not completely out of sight. A row is being tested in the greenhouse.

Kees: “As a grower you always keep a few options open. This is especially useful during this time. With what is going on now, a lit tomato cultivation could be an option. As a grower you always try to look for what no one or only a few are doing yet. It's not easy, but you try. That was the case with autumn tomatoes, with geothermal heat and now with full LED again.”

The row of tomatoes is in the greenhouse where cucumbers were grown on 2.1 hectares with full LED in the winter of 2021/2022. It is striking that the plants are relatively young.
Kees: “This spring, the cultivation went out early in the lit greenhouse and we started a new crop. In November we hadn't thought that yet, but two months later we chose this because the costs were too much for us, even with the use of geothermal heat. Electricity became so expensive. We then made a calculation, quickly started a new crop, we started to use the lamps differently and that way we reached the market early. That went well. Until we encountered a very dark period in April. Then you just didn't want to turn on the lights, given the cost.”

Leo nods. “Even if you have a plan, you have to stay flexible. After all, horticulture is characterized by many fluctuations. You have to resist that. A sounding board helps. That is my role, but certainly also that of Barend.”

Kees: “Friends of mine from other sectors don't understand it when I say that in horticulture you often don't know exactly what you're going to earn until very late. You have good years and less good years. It is important that those less good years do not occur too often in succession. And that if things go a little less, you can explain why that is. As long as you can do that, you'll be fine.”

Once in the greenhouse, the new cultivation in the greenhouse with LED lamps is in full swing. Kees, Leo and Barend are walking around. Satisfied?
Kees: “What I find most special is that there is virtually no abortion, not even in the height of summer. I think you can really see the effect of LED here, especially if you use it all year round.”

Leo: “Many growers still have an HPS mindset. Now that they also use LED in the summer, you try to get the most out of it. We started with maximum lighting, but now that energy prices have started to rise, the focus is on optimal lighting. There is still a lot to learn about that too. The first year here in the greenhouse was dimmed based on irradiation, now we dim based on energy prices. It's a matter of being flexible."

Kees gives an example: “If I had known a month ago that cucumbers were going for 80 euro cents towards Easter, I would have turned on the lights. But yeah, you can't predict that."

Barend: “If there was already a scenario for full LED lighting in cucumbers, it could have been thrown out last winter. So to speak. Together we have already gathered and stored a lot of valuable knowledge. So we really do keep the script.”


For more information:
Barend Löbker
[email protected]


Leo Lansbergen
[email protected]

Kees Vahl
Gebroeders Vahl BV
[email protected]