Home Posts Tagged "innovation"


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Gee Vee Enterprises was founded in Harlow, UK, in 1997 by husband-and-wife team Gaetano and Vincenzina Cappalonga. The site is based in the UK’s Lea Valley, which has a rich horticultural heritage. The growers originally started with chrysanthemums, but when that industry suffered a downturn in 1999, Gaetano made the bold but ultimately successful decision to switch to producing peppers instead. Since taking over the running of the company several years ago, their son John has invested heavily in producing high quality at low costs, including through a sizable expansion, and he is continuously looking for innovative ways to make further improvements.

Certain level of expertise

John joined the company in 2006 and it has gone from strength to strength ever since. Its high-quality peppers are supplied through the marketing company Abbey View Produce to grocery chains and markets across the UK.
“Growing peppers is very much a waiting game,” says John Cappalonga. “It’s like playing chess; it takes three months for a pepper plant to grow and another eight weeks for a pepper to mature, and then you’re in full production between June and September.”
“We employ 11 members of staff, all full-timers. There’s an element of caring about the crops and the business that you only get with full-time employees. They also need to have a certain level of expertise, and that can only be achieved through training. Of course it’s seasonal work, but when that season is up to 11 months long we prefer to keep the same team from beginning to end,” he continues.

No-nonsense sustainability

Cappalonga’s focus has always been on high quality at low cost. He takes a no-nonsense approach to sustainability, stating that it only makes sense if it is commercially viable too. But he has found plenty of ways to reduce the company’s environmental impact while also keeping costs down, including by using biodegradable products and raw materials to reduce waste, and saving energy by harvesting rainwater and recycling 100% of the water used. “Although water is abundant in the UK, it is so fundamental for crops that I believe we should take a little bit more care about where it comes from and how we use it,” he adds.
Gee Vee Enterprises currently has four glasshouses amounting to three hectares in total, but the site actually comprises five acres and planning permission is in place for further expansion. They produce red and yellow blocky peppers (Nagano and Jorit, respectively) in the newest and largest glasshouse. “Then we have Palermo sweet pointed peppers in the medium-sized glasshouse, and baby snack peppers in the oldest one, which is a Robinson dating from 1974,” explains the grower. “By growing different crops in different greenhouses, we not only adapt to what the market wants but also to what the greenhouse wants.”

Four seasons in one day

The newest glasshouse, which comprises 12,000 m2 with an integrated packhouse and office, was built in 2011 as the result of a £ 1.5 million investment project. Cappalonga received backing from Barclays Bank at a time when the industry was still reeling from the financial crisis. It is equipped with state-of-the-art technology including a high-tech Bogaerts automation system, irrigation and water recirculation systems, hanging gutters, thermal screens and robotic harvesting trolleys.
“Growing peppers requires a very technical approach because the yield and fruit load can be affected by all kinds of factors, such as the amount of light you get early in the year or a nice mild winter like we had last year. So we try to combine high-tech techniques with the old style of growing to make the most of the weather, but it’s difficult to maintain a stable greenhouse climate when you’ve got four different seasons in a day, like we do in the UK,” he comments.

No light at all

The changeable climate can certainly pose problems. “Early in the year, the light intensity is actually higher than in the summer because the sun is still low in the sky. Sunlight comes in through the glass at an angle and can scorch the leaves,” he explains. “Also, conflicts can occur in the environmental system; the heating switches on and the vents close because of the cold outside temperature on chilly but sunny days. Even when it’s cloudy, if the wind suddenly blows the clouds away you’ve got hot pipes, closed vents, high humidity and intense sun on the crop – which is the opposite of what you want for peppers. We have electric screens as a shading mechanism on the roof and also on the sides, but on a dull day shading means you’ve got no light at all.”

Diffusion coating

Faced with this frustration, the grower was interested when his advisor recommended a solution from Dutch firm Mardenkro. “I heard that the ReduFuse removable coating diffuses light on a bright day but lets it through on a dull day. I’m a complete sceptic so I had to see it to believe it. We tried it in the greenhouse with Palermo. This variety is very light-sensitive and has a higher risk of blossom-end rot. I was amazed at the result. It looks like diffused glass in direct sunlight, but without direct sunlight the glass is as clear as day. It’s an unbelievable product that really helps with light intensity inside the greenhouse, facilitating a controlled indoor environment that is better suited to peppers. It also creates a more pleasant work climate for employees.”
Cappalonga has been using the coating for around five years now, from April to September. “Although we don’t use it for all our peppers for cost reasons, it’s a winner for the Palermo. This premium variety makes it easier to justify the investment.”

Research and innovation

In addition to physical expansion plans, he is keen to explore how other innovative solutions can help him to take the business to the next level. “I’ve always been a fan of new ideas and new approaches, even from an early age. In that context, I recently visited the Netherlands on a two-day horticultural tour co-organised by In Greenhouses magazine. I’ve been on similar trips in the past and they often revolve around networking, but this was the first time I’ve noticed such a strong technical focus and have been able to connect with academics and experts from both within and outside of the industry. It was refreshing and insightful to discuss what can and could be done rather than what has already been done.”
In parallel with his business activities, Cappalonga is actually working on an academic research project and hopes to become the first commercial pepper nursery in the UK to implement LEDs. “We have a small area where we’re currently testing lots of LEDs to explore not only the commercial viability but also if there’s a consumer marketing angle. We can already manipulate almost anything: heat, humidity, water; everything except the light. It’s the missing link and I believe LEDs could be the solution,” he concludes.


Gee Vee Enterprises produces a mix of blocky and pointed peppers on three hectares of high-tech greenhouses in the UK’s Lea Valley. Since taking over the running of the company several years ago, John Cappalonga has invested heavily in producing high quality at low costs. As a big fan of new ideas and new approaches he is continuously looking for innovative ways to make further improvements. Recent projects include the use of a diffuse coating system to reduce the light intensity and trials of LED lighting.

Text: Lynn Radford. Images: Gee Vee Enterprises.

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Diffuse glass is becoming routine in new build greenhouses – and much more quickly than anticipated. But it is still difficult for growers to estimate precisely what added value it has for their crops. So researchers Silke Hemming and Tom Dueck are calling for growers to share much more of their experiences. Here they look at some of the issues faced by growers in practice.

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The third edition of GreenTech Amsterdam, which runs from 12 to 14 June, will be twenty percent bigger than the last edition in 2016. By the end of March, ninety-seven percent of the available stand space had been allocated. According to the organisers, RAI Amsterdam, this proves that the event has really made its mark as an international platform for the horticultural sector. As in previous years the trade fair will feature a wide range of seminars, some of which will be held in the new themed pavilions.

Awaiting the international delegates this year will be at least 450 exhibitors, including world market leaders and innovators in horticultural technology and a full compliment of greenhouse builders, horticultural suppliers, machinery companies, potting compost and substrate producers, lighting vendors and seed suppliers.

Knowledge programme

Ever since the first GreenTech in 2014, the organisers have aimed to make this trade fair stand out from other similar events by offering a wide-ranging knowledge programme. The upcoming edition will therefore feature more than 80 seminar sessions spread over three theatres: Food & Flower Crops, Climate, Water & Energy, and Trends & Innovation.

In addition to the Vertical Farming Pavilion introduced in 2016, this year’s event features two new pavilions: the Precision Horticulture Pavilion and the Medicinal Crops Pavilion. The Precision Horticulture Pavilion will showcase censoring technology, cameras, robotisation and digitisation, while the Medicinal Crops Pavilion will focus mainly on technology for medicinal cannabis production, a subject that will also feature in the knowledge programme.

Following its success two years ago, the Vertical Farming Pavilion is to make another appearance this year. “In 2016 we embraced the discussions going on within the sector as to whether this would be the future of global food production,” exhibition manager Mariska Dreschler says. “The fact is that it is a very interesting development from a technological point of view. In this pavilion we explain exactly what the technology entails and we will also be demonstrating some cultivation systems, reflecting some of the many new initiatives in this field in recent years.”

Objective dialogue

The informative theatres are partly made possible by some of the international heavyweights of the horticultural sector, including Koppert, Biobest, Svensson, Hoogendoorn, Hortimax, Priva, Philips and Alumat. “We are very proud that these companies and organisations have expressly affiliated themselves with this initiative,” Dreschler says. As of early April, it is hoped that even more companies will contribute to the knowledge sessions. “Their knowledge and expertise make these sessions a must for any grower. Together we will produce an outstanding programme that shines the spotlight on the international grower’s day-to-day practice.”

Advisory Board

A committee of experts is advising the organisers on the themes, subjects and speakers for the knowledge programme. This Advisory Board was set up to ensure an objective dialogue on subjects of topical interest within the rapidly evolving horticultural sector.

The members of the Advisory Board for this edition are: Sjaak Bakker, chair (Wageningen University & Research), Aad van den Berg (Delphy), Gabrielle Nuijtens (Top Sector Horticulture & Propagating Materials) and Michael Ploeg (Dalsem). “We are delighted to have such a prominent Advisory Board at our side,” the exhibition manager says. “This way we can ensure that the knowledge programme is made up of sessions that will challenge growers and encourage them to push the boundaries. The Board’s expertise and experience are of inestimable value to our programme.”

The Organic Farmers Fair

This year GreenTech will also be the venue for The Organic Farmers Fair (TOFF). For three days, the spotlight will be shone on knowledge and innovation in organic agriculture and horticulture. This part of the event came about as a result of a collaboration with IFOAM and FiBL and has been made possible partly thanks to five partners: Bejo, DCM, Steketee, Koppert Biological Systems and Delphy. Wageningen University & Research is also involved as a supporting partner.

The organisers have put together a high-quality knowledge programme on organic farming, with in-depth coverage of the most relevant issues in this field. TOFF is aiming to become an international meeting place for organic growers as well as conventional growers considering the switch to organic.

Forefront role in organic farming

The Netherlands plays a leading role in the technical development of both organic and conventional agriculture and in increasing and improving production. The domestic market grew by 11.5% in 2015 and by 13% in 2016, to around €1.5 billion, with exports of €1.2 billion. The total EU market exceeded €30 billion in 2016. Annual turnover in the world market is heading towards the €100 billion mark.

Markets are developing fast, but so is organic farming technology, with several thousand companies supplying products and services to organic farmers across the globe. So it was a logical step to combine the momentum of the TOFF event with GreenTech 2018 at RAI Amsterdam. Delegates can also take the opportunity to visit some innovative organic farms and demo fields in the Netherlands.

The future of horticulture

The GreenTech Summit takes place on 11 June, the day before the exhibition opens. This seminar offers 750 investors, breeders and growers a unique opportunity to network and to take part in a high-quality programme of sessions. Under the title “The future of horticulture – insights for the next decade”, visionaries and experts will be sharing their vision of the world of horticulture over the next ten years.

The summit will be hosted by stand-up comedian Greg Shapiro and will feature speakers including Stijn Baan (Koppert Cress), Martin Koppert (Koppert Biological Systems), Mike Vermeij (BOM Group) and Christian Kromme, futurist, speaker and author of “Humanification”. Kromme will help unlock the DNA of innovation and will explain how to apply it in our horticultural businesses and our daily lives.

Flower Trials

The direct tie-in with the Flower Trials breeders’ event delivers great added value, the exhibition organisers believe. “The two events were held simultaneously in 2014, and there was some mutual interaction in 2016. We will be continuing this collaboration this year,” Dreschler says.

A greenhouse is to be built in the exhibition hall, where ornamentals breeders taking part in the popular open days will be presenting their products. Vegetable breeders’ crops will also be on display, ensuring that this key greenhouse horticulture segment is also represented at the show. The breeders’ pavilion looks set to be an impressive experience and a good starting point for the visits to breeder organisations.

Innovation Award

One of the highlights of the first two editions of GreenTech was the much coveted Innovation Award, which attracts more and more entries each time. This award forms part of the exhibition’s efforts to stand out internationally in the areas of knowledge transfer and innovation. “We want to showcase all the latest trends and developments,” Dreschler says. “I would even go so far as to say that no other horticultural trade fair in the world shines the spotlight so emphatically on its innovations.”

Annual international trade fair

Dreschler says she will regard the 2018 edition as a success if it gives rise to synergies between exhibitors and delegates that lead to potential business. “We will once again use every indicator at our disposal to gauge satisfaction levels among the various target groups. If delegates tell us that they have learned something new and will come back to Amsterdam again next time, then we’ve done a good job.”

Note that the fourth edition of GreenTech will not be taking place in 2020 but in 2019, as the organisers have decided to turn it into an annual international trade fair.


The third edition of GreenTech takes place in Amsterdam in mid-June. This year’s event will be bigger than the last one in 2016, both in terms of floor area and delegate numbers from the Netherlands and abroad. This time there will be even more focus on knowledge transfer and innovation: various themed pavilions will highlight topical issues in international greenhouse horticulture, and an independent Advisory Board will be keeping a close eye on the quality of the knowledge programme. The organisers have decided to switch to an annual event from 2019 onwards.

Text: Roger Abbenhuijs.

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Dutch Rhododendron grower Frans Kortenhorst was looking for a way to get rid of weeds and moss in his pots for good. He cut squares out of a roll of cling film and a bin liner and secured them around the top of the pot with a rubber band. In the middle he made a hole for the plant. Six years later, this idea has a name and it has the support of his horticultural supplier.

With his engineering background, rhododendron grower Frans Kortenhorst from Heeten in the east of the Netherlands is always looking for ways to innovate and automate his business processes. But his best ideas come during quiet periods at the nursery. He was fed up with having to remove weeds and moss by hand to get the plants ready for delivery. “Having 300,000 pots pass through your hands is a massive job that has to be done every year.” Laughing, he says that preferring an easy life makes a healthy starting point for innovation and encourages him to optimise and get creative.

Weed and moss problem

According to René Janssen, Substrate Product Manager at horticultural suppliers Horticoop, the Cleanpot System is an enormous improvement. Unsurprisingly, their enthusiasm has resulted in collaboration with Frans Kortenhorst.
The weed and moss problem in pot plant cultivation is tackled by covering the surface of the pots. Bark chips go quite a way to reducing weeds and moss, but not enough for Kortenhorst’s liking. “The retail channel is not very happy with the stuff either,” the grower says. “Bark makes a lot of mess: it lies loose on the surface of the pot, it falls on the shop floor, on the conveyor belt in the greenhouse and in the customer’s car – those kinds of complaints.”

Step by step

The idea of covering the pots with film was something Kortenhorst thought worth trying. He ran a trial with both transparent and dark film on five pots in the first year, followed by thirty pots in the second year. It immediately became clear that the film didn’t harm the plants. The transparent film was dropped straight away, but the dark film suppressed weed and moss growth completely. All the additional benefits were an added bonus. “We cut our watering by 25% and I got rid of Sciarid fly in one fell swoop,” he says.
Kortenhorst designed a machine to fit the film to the pots and built the prototype in his own workshop. “We introduced it at our nursery in stages – 10,000 pots in the first year, 100,000 in the second year, and our total production of 300,000 after that.”

Longer shelf life

Retailers have welcomed the system. Kortenhorst made sure of that before introducing it throughout his operation. Most of his dwarf rhododendrons are sold in Lidl Europe stores. The most positive aspects for the retailers were the longer shelf life and the fact that the pots were cleaner to work with. The shelf life of the plants is a good four days longer because the potting soil stays moist. What is more, most consumers don’t even notice the film to begin with when they buy the plant. They have to remove it when they get home, of course, along with the handle.
However, from the point of view of sustainability, it is still plastic, and that needs work. Kortenhorst: “We would really like to switch to a biodegradable material. But while the pot, the label and the cover are still all made of plastic, it is better if the film is plastic too. Then they can all go into the recycling together.”

Wide range of uses

A substrate specialist from Lentse Potgrond (a division of Horticoop) spotted the film on the pots during a routine customer visit around six years ago, and it immediately caught his attention. Janssen envisages a wide range of uses for cover film in the trade channel. “We were very impressed with the idea,” he says. “After all, the use of film also has a bearing on the growing medium. It doesn’t physically touch it, as there has to be a 2 cm air buffer between the film and the potting compost for oxygen exchange and to stop mildew from forming.”
Horticoop is keen to raise awareness of the Cleanpot System because it could have potential for many growers and groups of crops. The company has therefore worked with Kortenhorst, the inventor, and machine builders Linthorst Snijtechniek to develop a machine that combines potting up, applying the film and planting the plants in one fluid movement.
Apart from the great advantage of reducing moss and weed growth, the initiators report a whole host of other beneficial effects that occur in the pot. First off, Janssen mentions the homogeneous moisture distribution in the pot. That is because there is no transpiration taking place; the water condenses against the film and drops back into the growing medium. It also reduces the amount of crop protection products, water and fertiliser needed and extends the shelf life of the plant.

Specific reasons

According to Janssen, this is an interesting concept for many ornamentals. From the point of view of sustainability, the water efficiency aspect is something that is bound to appeal to all growers, he believes. “It is also a sustainable way of dealing with soil pests. There are some specific reasons as well. In cyclamen, for example, the film can prevent a botrytis attack on the bottom leaves. And in orchids the system can stop roots crossing into other pots. Sometimes the roots from one pot will grow into other pots nearby, and when you pick up the pot, you drag the other plant along with it.”
The more experience growers gain with this system, the longer the list of applications and benefits gets. Bunnik Plants from Bleiswijk in the west of the Netherlands are also testing the system. Improving shelf life in the supply chain is an important issue for them. Kortenhorst again: “If it was only about moss and weeds, it would have died a slow death. But when it is a question of sales or no sales, then it’s a no-brainer.”

Running own business

Kortenhorst runs the 2.5 hectare rhododendron nursery with his sister and brother-in-law. Plastic film greenhouses are not what you’d necessarily expect to see in the middle of verdant countryside resplendent with farms, villas, cows and sheep. But the oldest greenhouses have been here for almost 30 years.
His sister Gonny set up the nursery after completing her horticultural training, on the spot where their parents’ cows used to graze. Her husband Jos joined her five years later. And five years after that Frans decided to give up his job as a mechanical engineer at a machinery factory and join them. “What attracted me to running your own business is that you can shape it the way you want it.”

Time for innovation

Today’s nursery looks nothing like the one that started out all those years ago. Back then they grew a wide range of plants which they sold locally, focusing mainly on the retail market. Twenty years ago they decided to sell their products via Flora Holland and gradually reduced the size of their product range. These days Kortenhorst is well known as a specialist grower of dwarf rhododendrons. The plants go to retail and all sales take place by auction. The bulk of the plants are exported.
With the exception of the two busy periods – when the cuttings are planted and in the selling season – the three entrepreneurs do all the work themselves. “We are very happy with our present size; we wouldn’t want to get any bigger. We make time to innovate, which we think is very important and fits well with who we are,” Kortenhorst concludes.


It started out as a solution for suppressing weeds and moss in pots, but the system created by grower and inventor Frans Kortenhorst is much more than that. With a simple piece of plastic film on the pot, the benefits are there for the asking. The system has nothing but beneficial effects during production, for retailers and for the consumer at home, he says. The concept also offers scope for a wider range of applications in horticulture.

Text: Suzan Crooijmans. Images: Rikkert Harink.

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Around two years ago, Dutch rose breeders Schreurs wanted to take their hygiene and quality control to a higher level. After setting up their own stock of mother plants they were looking for a new spraying method for newly stuck cuttings. This led to an innovative spraying technique that is both effective and efficient. It is perfect for cuttings and low, compact crops on mobile benches.

Peter Schreurs looks back on the upgrade of their hygiene and quality control programme with satisfaction. Their business processes and working methods around disease prevention and nursery hygiene have been reviewed and changed in various areas. “A lot of aspects are involved in this, such as temporarily isolating and testing plant material coming into the nursery, disinfecting Danish trolleys and tightening up some of our work routines,” he says.
One of the measures introduced to reduce the risk of infections is propagating rose crops in-house. “We used to buy plant material from rose growers,” Schreurs explains. “But that didn’t give us enough insight into the health status of the plant material, with all the risks that that entails. So we started expanding our mother plant stocks at our headquarters in the Dutch De Kwakel. Now propagation and production take place in separate departments on the same site.”

Optimise crop protection

The rose breeder was also looking to optimise crop protection during the production phase. “We do all we can to grow on cuttings perfectly and deliver clean plant material to the customer. Safety for people, animals and the crop are a top priority and we try to minimise our use of chemicals wherever possible.”
The first treatment takes place immediately after the cuttings are stuck. Up until the middle of last year, this was done in the greenhouse using standard spraying equipment. But despite the staff taking the utmost care, they did not always manage to cover all parts of the crop with the spray. So Schreurs turned to Theo Straathof of Micothon Spuittechniek to find out whether he could offer a better method.

New technique needed

“I didn’t have a better off-the-shelf spray technique to offer them,” Straathof says. “We mainly produce systems for production nurseries. They often have dense crops and there is usually a big gap between the spraying equipment and the crop. In those situations, air assistance is a standard tool for getting the spray liquid deep inside the crop and achieving maximum coverage. This kind of method is too heavy-handed for young cuttings material.”
A completely different technique was needed, so supplier decided to revisit the electrostatic spray technique he had experimented with in the past. This can produce a very fine spray mist with electrically-charged microdroplets which adhere perfectly to all parts of the crop. Because the mist does not penetrate well, Micothon had not pursued this technique for use in greenhouse horticulture at the time.
“But that’s not a problem for rose cuttings because they are less than 10 cm tall,” the spraying technician continues. “I thought this principle could be used to design a good system for the rose propagator.”

Development process

Straathof resumed development of his electrostatic spray technique. First he concentrated on developing a nozzle that could produce a mist with fine, electrically charged droplets. It was a real challenge to get the spray liquid, the electrical charge – supplied by a built-in spark plug – and air in contact with each other at the right time and in the right proportions. Air assistance is needed to create a swirling current that gets the spray into the crop. The electrical charge then ensures the spray is distributed homogeneously and adheres to all parts of the crop.
He reckons there will be more demand for the Micothon Topstart, as the spray cabin is now called. “This spraying technique is perfect for low crops on mobile benches combined with automated transport systems. Several plant propagators and pot plant growers have already expressed their interest. The pioneering work is done, but these kinds of systems still need a lot of customising.”

Fully automatic

After a while they found the right recipe. Extensive trials with fluorescent powder showed perfect leaf coverage on both sides. Schreurs was impressed but as yet had nothing he could work with. “This technology lends itself best to automated application in enclosed spaces,” the supplier continues. “That meant building a closable spray cabin which the benches could roll through. Plus we had to integrate it into their existing internal transport system.”
The basic spray for rose cuttings consists of a tank mixture of various products. The spray liquid is cooled in the tank and kept moving to stop the mixture from separating. The pipes and the cabin are flushed clean every evening after use. Before treated benches leave the cabin, they are ventilated for thirty seconds via an active carbon filter to minimise emissions into the environment. The cabin has its own capture and drainage system for residual spray liquid and rinsing water.

80% saving on liquid

Schreurs first spoke to his supplier about this in November 2015. By January 2016 they had an action plan in place and the spray cabin was installed in early June last year. “It’s an expensive piece of kit, but we are delighted with it,” he says. “Firstly because it produces a better spray result, which means we have less trouble with pests and diseases in the greenhouse so we have to spray less. Secondly, the automated process means less work and we use less spray liquid.”
For a basic spray, they used to use 100 litres of spray liquid per 100 benches. Now that’s down to 17.5 litres and with a better end result. “I should mention that the pressure from pests and diseases is less anyway now since we have been propagating our roses in-house from our own mother plants. The fact remains that it’s a fantastic piece of kit.”


An innovative spray cabin has been developed which produces a fine, electrically charged spray mist. This provides highly homogeneous crop coverage and good pest control results with a very small quantity of spray solution. At present this technique is only suitable for cuttings, seedlings and low crops on mobile benches.

Text and images: Jan van Staalduinen.

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With its recent acquisitions of Wander Tuinier Succulenten (June), Hobaho (September) and Olij Rozen (October 2016), Dümmen Orange has once again been making the headlines. The Dutch ornamentals breeding conglomerate is aiming for a global top three position in the ten best-selling crop groups and is not wasting any time getting there. “There is still a whole lot to gain in ornamental plant breeding,” says CEO Biense Visser. “We’re working on that.”

The name Dümmen Orange is not that familiar to many in the sector. And that’s no surprise for a company that was called DNA Green Group until the spring of 2015, and even then was known mainly for the big names under the corporate umbrella, such as Lex +, Bartels, Ecke, Terra Nigra, Dümmen Group, Rijnplant, Fides, Red Fox and Barberet & Blanc. Not to mention the Agribio sister companies in Latin America and Asia.
CEO Biense Visser was brought in more than two years ago to channel growth, take R&D to a higher level and transform the many specialised companies – each with its own culture and history – into an entity that is more than the sum of its parts. He is achieving this mainly through corporate values and programmes focusing on corporate social responsibility, sustainable production and quality assurance.

Sales market changing

What is feeding Dümmen Orange’s growth ambition? Visser: “The realisation that the sales market is changing. In the United States, as many as 60-70% of ornamentals are now sold by big box retailers like Walmart and Home Depot. And it’s heading that way in Europe and Asia too. These companies’ category managers can spend up to three years translating range selections into sales-ready concepts and adequate volumes. If you want to get in with these parties, you need to involve them in what you’re doing at an early stage. And, if possible, offer a complete programme in the crop top ten. That’s what we are aiming for, because we want to be a serious discussion partner. To achieve this we will have to take bigger steps in innovation – for consumers, retailers and, of course, growers – as well as in terms of expanding and upscaling.”

The promise of biotech

From 2002 until its takeover by Monsanto in 2008, Visser was CEO of the Dutch seed breeding company De Ruiter Seeds. He knows a thing or two about the breeding business and also has experience in business acquisition. According to the CEO, breeding practices in ornamentals lag behind those in vegetable production.
“Vegetable seeds have been produced using state-of-the-art techniques for decades,” he says. “You just have to think about DNA-assisted breeding and genetic markers, cell biology techniques such as embryo rescue, the dihaploid technique, and so on. Producing hybrids with inbred lines is standard practice. We hardly ever see these techniques in ornamental plant breeding yet; people tend rather to work on a trial-and-error basis and using visual selection. A lot of crops are largely bred by amateurs. And with all due respect to their dedication and product knowledge, crossing plants is not the same as targeted breeding. The latter is our core business.”
To enable it to work in a smarter and more targeted way, Dümmen Orange is a shareholder in Wageningen-based Genetwister, a company that is pushing the boundaries in biotechnology. This makes it the only business in the ornamentals sector that is investing in new knowledge and applications at this level.

Unnecessarily time-consuming

Inefficient processes make the time that lapses between crossing and market launch much longer than necessary. Visser cites the tulip as an example. It takes five years for the seed from a cross to form a bulb that can propagate itself. Depending on the offset factor, it would take another 15-20 years to produce one hectare of bulbs of this new variety, if it is found to be suitable. “There is definitely scope for improvement there,” he believes.
There are several reasons why ornamental plant breeding is lagging behind. For example, many ornamental crops are not propagated generatively but vegetatively, making the creation and maintenance of specific parental lines less pressing. Nurseries also tend to be much smaller and the diversity of species and varieties is much bigger than in food crops, so the threshold for investing in expensive biotech is higher.
Visser doesn’t brush aside those differences but refers once again to food crops. Breeding in that sector also used to be done using traditional methods, except with just ten to twenty companies working at it in the Netherlands. The fact that these companies have grown enormously in the last thirty years is a logical result of consistent investment in innovation (seed technology, cell biology and DNA technology), upscaling and international expansion, Visser believes. “This should be achievable with ornamentals too,” he says. “You just have to have the courage and the ability to take that step. That requires vision, a whole lot of money and the confidence that it will be recouped.”

Deep pockets

Clearly, the investors behind Dümmen Orange have that confidence and their pockets are deep enough to finance the rapid expansion. Who are these investors and what motivates them?
Visser: “The consortium was set up by Agribio Management, with financial support from banks and the Amsterdam private equity fund H2. Private equity is venture capital that is put together by pension funds and wealthy individuals. They fill a pot with money and invest specifically in one or more companies. The return should primarily come from the appreciation in the investment over the term, which is usually between five and seven years. Ultimately the interests are sold and the investors get their money back plus the return realised.”
Shortly after Visser joined the company, H2 sold its stake to the British private equity fund BC Partners, which had an even bigger pot. “And they saw the potential in our company, otherwise they would not have taken this step,” the CEO continues. “With the new capital injection we can expand our organisation – especially the R&D and ICT departments – and our breeding programmes more quickly through business acquisitions. We must all work together to ensure that this company represents greater value by 2020, when BC Partners are likely to withdraw.”

Colouring in the white spots

They are working hard on that. Managing Director R&D Hans van den Heuvel (also from a vegetable breeding background) has headed the central research department since January 2015 and a lot of young, highly trained specialists have been taken on. The group will shortly be opening an elite centre for mother plants in Rheinberg, Germany, and something similar will be happening for tissue culture in Spain.
Nevertheless, it will take many years to capture a 25% market share in each of the top ten crops. “We are well on the way with rose, chrysanthemum and carnation, but there are also some white spots on the map,” Visser acknowledges. “In tropical plants, we already work with Anthurium, but we don’t yet cover orchid and Bromelia. Flowers from seed are another white spot that we still need to colour in. Ball Seeds and Syngenta dominate that market segment but they are not for sale. Starting from scratch is too time-consuming and if you take over small businesses you have to buy a whole string of them to make any impression. Collaborating with parties in the middle segment makes the most sense. We’ll see what happens. But one thing is certain: this company is going to be producing varieties that growers and consumers can currently only dream of.”


To be able to serve the major international retail chains properly, ornamental breeders Dümmen Orange want to achieve at least a 25% market share in the ten best-selling crop groups. They are working towards this with business acquisitions, collaboration and a firm commitment to innovation. Investments in seed technology, cell biology and DNA technology are expected to result in a significant acceleration of crossing and selection programmes and in varieties that provide more added value for growers, wholesalers and consumers alike.

Text: Jan van Staalduinen. Images: Studio G.J. Vlekke.

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By the end of June 2016, time was getting tight for cucumber grower Marco Zuidgeest. If he wanted to grow the innovative small core cucumber again this season, he would have to get an order to sow in soon. But the feedback from the customer was taking its time. Zuidgeest: “And with this sort of supply chain project, you can only move forward once everyone is happy. I’m a big fan.”

Zuidgeest has been selling cucumbers to the British company Greencore under contract via the Best of Four growers association for six years now. This convenience foods producer uses vegetables in ready meals, sandwiches, wraps, baguettes, sushi – you name it. The Food to Go division produces around 500 million pre-packed sandwiches per year. And what would a sandwich be without fresh slices of cucumber?
“Oh yes, they are a good customer of ours,” the cucumber grower continues. “We supply them with standard length cucumbers, and of course it’s always nice to have something special to offer. So I regularly ask the vegetable breeders whether they have anything new we can try.”
Cucumber crop coordinator Marcel van Koppen also heard his request, which immediately got him thinking about the variety 24-250 RZ. “Rijk Zwaan has been working on cucumbers with a smaller core for a while. Now we had a variety that came through our internal trials well. Marco wanted to try it out at his nursery, providing the customer agreed.”

Demand for “drier” cucumbers

The vegetable breeding company in De Lier already has several supply chain projects on the go and benefits from existing contacts with sectors such as the convenience market. “Our people keep in close touch with vegetable processing companies. You just have to think of lettuce for pre-packed mixes. The collaboration is mutual, by the way: we brainstorm, solve problems and come up with new products together.”
Special breeding programmes focus on aspects such as keeping qualities, colour and taste. “We started getting requests for a different type of cucumber some years ago. Processors wanted a slightly “drier” variety to use in sandwiches. As we all know, sandwiches with slices of cucumber in them often go soggy quite quickly. Ever since then, our breeders have been working on a fruit with a higher dry matter content. And a smaller seed core – the processing company removes this, so the smaller the core, the more flesh they have left over to use. Now that we have finally developed a potentially interesting variety, it’s time to put it to the test in practice: at Zuidgeest in the Dutch village Delfgauw.”

Second chance

The cucumber grower had already tested the variety on 150 m2 last season. “We used it as an intermediate crop. It was quite difficult and we had trouble getting the crop balanced. It had a lot of foliage and weak fruits. But we realised that we could eliminate many of these problems by steering the crop separately. So this season we gave the small core cucumber a second chance.”
On 21 July 2016, Zuidgeest planted three rows totalling 1,000 m2. This time the crop did a whole lot better. “We harvested the first fruits on about 10 August and the last ones around 1 November. Of course there are differences. Compared with our main variety, this one produces around 15-20% less. But I’m not too worried about that now. At the end of October I picked a row myself and they were lovely, uniform cucumbers.” The diameter and weight of the two varieties is almost the same, the grower says. He aims to pick them at between 350 and 420 grams.

Harvesting separately

For the time being, Zuidgeest is harvesting the new variety separately. “Every day one of our regular staff members picks around 30 boxes, and we send two pallets off to the customer every two days. Having the same person harvesting these rows helps us supply a consistent size. We don’t sort this variety. We have agreed with the British customer that they will take all sortings. Look, there they are in those green crates.”
The Rijk Zwaan advisor picks up a sample out of a crate and compares it with a standard Lausanna RZ variety fruit. The first thing you notice is that the newcomer has a smooth skin. Otherwise it’s hard to tell the difference – at least until Van Koppen cuts the cucumber in half. Now the smaller core is clearly visible. He also squeezes a piece of the fruit. It produces quite a lot less water than when he does the same with a reference piece.

Only deliver perfect fruits

“Our customer has also seen that the fruit is drier, of course,” the grower says. “They recently sent a delegation over to visit us. You can tell straight away when someone is a trader and not a grower. For instance, I had to explain to them that a cucumber is a natural product and that you can’t simply harvest a specific sorting to order. I think they’d like to leave us a ruler so we only deliver perfect fruits! After all, they have done their calculations: ‘We are making x number of sandwiches, so we need y slices of cucumber and we get z slices out of one fruit, so we need so and so many fruits.’ I do my best, but of course it depends on a variety of factors. Fortunately they went away with a better understanding of how it all works.”

Sandwiches stay fresh for longer

Greencore sandwiches find their way to an average of 45,000 outlets per week across Great Britain alone, such as supermarkets and petrol stations. The sandwiches are sold under their own label. Both Zuidgeest and Van Koppen are looking forward to hearing what the company has to say about the new cucumber. Does this cucumber have a future?
Both the grower and the advisor firmly believe in the added value of this product. But if the customer doesn’t think the higher price is worth paying, it stops here and now. After all, the downside of this variety is its lower production.
Zuidgeest: “The small core cucumber has a lower yield and is more labour-intensive. But if you want to stand out, you have to try something new now and again.” Luckily the customer is also happy with the trial. They report that the quality and specifications are fully in line with their expectations. They are seeing less moisture loss from the product during processing, which is improving the quality of their sandwiches. Larger-scale trials will be carried out over the next few weeks. Van Koppen: “For companies like this, switching to a new type of cucumber doesn’t happen overnight. It’s not a question of weeks but rather months. After the crop, an extensive evaluation will take place.”

All parties benefit

The vegetable breeder is fully aware that the cropping traits of this variety still need work. “Our breeders are working on this at the moment. Variety development is a lengthy process, and with initiatives like this one you still have to contend with the trade-off between the different needs of the parties in the supply chain. The art is creating a range of vegetable varieties that both processors and growers can profit from to the max.”
In this kind of supply chain project, sharing knowledge is extremely important. Most of the contact between the grower and the customer takes place via the breeding company in De Lier. Zuidgeest: “They already have the lines of communication in place and they have special people to handle this. Afterwards, I get to hear from Van Koppen who wants what. It would take up too much of my time and energy to have to deal with that myself. It’s great that we can all work together this way. The breeder responds to current needs with new varieties, I can make my business as a grower stand out by offering a special cucumber, my customer can put sandwiches with added value on the shelves and the end customer gets a more appetising lunch. Here’s hoping this takes off!”


Marco Zuidgeest from Delfgauw grows the small core cucumber specially for the British food processing company Greencore. The characteristics of this fruit meet their needs perfectly. It’s a great example of customer-focused product innovation. To succeed, the project needs good communication between all the parties. With wants and needs being constantly fed back, improvements can be made.

Text: Jojanneke Rodenburg. Images: Leo Duijvestijn.

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Constant innovation is the key to Metrolina Greenhouses becoming one of the largest and most successful greenhouse growers in the USA. For over four decades the family-run enterprise has continued to invest in technology including robotics, data analysis and logistics. It produces around 700 species and is currently laying the foundations for further expansion to keep up with market demand.

The 68 ha of glasshouses in Huntersville and the 70 ha for outdoor cultivation in York, North Carolina, are a far cry from the 1860 m2 that Tom and Vickie van Wingerden bought in 1972. With 5,000 dollars in their pockets the Dutch couple had just emigrated from the Netherlands to start their American Dream. Today the business is run by their four sons and has a turnover of over 200 million dollars. It produces 110 million seedling and cutting plugs per year which in turn produce 7 million hardy chrysanthemums; 6 million summer annuals; 5 million hanging baskets; 3 million poinsettias; 1.8 million bedding plant trays and 11 million perennials. And each year 5% of sales are made up of new items.

Extremely modern

But the company is not resting on its laurels. Tom van Wingerden’s motto was ‘the absence of innovation means stagnation’ and with that front of mind the family continually invests to improve all greenhouse processes. “In our newer greenhouses we have rolling tables and benches, cranes and spacing machines doing all the work,” says Thomas van Wingerden, one of the brothers with responsibility for operations. “Trays are placed on the production line and are not touched by human hands until they are put on a shipping cart. In some of the older greenhouses, someone has to push the tables around but no one has to touch the plants,” he says. The company employs around 600 full time hourly people, 150 salary and 750 to 1000 seasonal staff.
Metrolina is without doubt extremely modern: Technology is king and the brothers collaborate with highly innovative suppliers from across the globe. But with their Dutch roots it goes without saying that they acquire much knowledge and expertise from the Netherlands. They recently invested in a new sticking machine which was manufactured for them by the ISO Group. “We wanted a machine for difficult varieties such as calibrachoa and verbena and for very small cuttings that are difficult to stick by hand,” says Thomas van Wingerden. The ISO Group, of the Netherlands, had such a machine for chrysanthemum cuttings which it was able to develop further. “The machine does a much better job than we can do manually because all the cutting are stuck uniformly so we have a much better success rate.”

Ahead of the game

Trying something new is part of the family’s philosophy. “We always want to be ahead of the game so if there is something better out there we want to have it.” That’s why they are currently replacing about 12 ha of shade screens with Svensson Harmony diffuse screens which should be in place by 1 February. “We’d seen the new screens at shows and after discussing it with our growers we felt they would be worth trying in our lower-light greenhouses. They should give better light than the Solaro 50% screens, which have an open structure to enhance ventilation and offer 50% shade. These are currently installed on 60 ha and double up as energy curtains which has led to significant savings,” says Van Wingerden. “We have also installed blackout curtains on 40 ha of glasshouses. These not only block out the light they are used for insulation too.”
The summers in Huntersville are humid and temperatures range from 32ºC, down to 15 to 21ºC. The winters, however, can be cold. Average winter temperatures range from the 4-7°C). The greenhouses in Huntersville are heated by four 8 MW woodchip boilers which were installed about seven years ago when natural gas was expensive. Although the gas prices have dropped, the woodchips, which come from a 50 mile radius, still make good business sense, he says. “They are still cheaper than gas and they are renewable so it’s better for the environment.” About 60 ha of the greenhouses have hot water pipe floor heating that has a capacity for some 19 million litres.

Renewable energy

While 6 ha of greenhouses are Venlo types with fan and pad cooling the majority are MX open roof greenhouses. As new houses have been added over the years they have become taller, the highest being 6.7 meters, to accommodate the robotic cranes that lift and move the trays of plants and the sprayer crane, another innovation that has improved efficiency. “The electrostatic sprayers put an electric charge on the chemical particle so that it sticks on the underside of the leaf where the bugs tend to hide. It is much more efficient: We use at least 50% less chemical product than previously but get the same coverage.”

Ozone clean water

About 48 ha have ebb and flood floors and the water is recycled in a closed system. The other 20 ha have a traditional system and the water returns to ponds for recycling. These ponds cover some 10 ha which collect 15 million litres of water for every inch of rainfall, says Van Wingerden. “We get about 45 inches of rain per year so we have plenty of water and we’ve not suffered any water shortages over the past ten years.” That’s saying something because the Huntersville facility consumes a staggering 5.7 million litres of water per day.
All the water is filtered and for the last three years has been sanitised using ozone. “We originally filtered to 150 microns and step by step reduced this to a finer filtration of 5 microns. The next step was ozone,” he says. It made such a positive difference that the system is being upgraded and will be used more widely. “Our plants are much healthier with better root systems which has allowed us to reduce the crop cycle. For example, we have been able to reduce the production time for poinsettias by four weeks and spring crops by two weeks. Although general improvements in growing techniques might have helped we certainly feel that the cleaner water has been largely responsible,” he says.

Big data

This typifies Metrolina’s philosophy of wanting to do better every day. It’s a strategy that is extremely reliant on data. “We record and analyse everything,” says Van Wingerden. “We employ at least 15 analysts who analyze everything going on in the greenhouse and connect it via the inventory management system to data from the stores. We have to make sure that all the numbers adds up. Our in-house database is updating information from every crop all the time. We use this information to speed up or slow down crops if we notice that plants are ahead or behind schedule. We can create about 50 different climates and with the additional use of artificial lighting we can ensure that crops hit their schedule dates.”
The database platform connects production planning, finance, replenishment and inventory management right through to shipping. They supplies three customers: Lowes (359 stores), Walmart (881 stores) and HomeDepot (150 stores, perennials only). The stores provide daily sales numbers so they knows which items are selling well. “Our analysts then decide what to ship to which stores the next day, a system that also requires an extremely innovative logistical solution, including 160 of our own trucks. Not only are we a producer of plants we also take care of the end-to- end process right up to sales to remove the hassle for our buyers.”

Keeping pace with demand

New greenhouses continue to be built. “Our customers are opening more and more new stores and growing by 2% per year. We need 4 acres extra per year just to keep up with the growth of their stores so we have just started to build an additional 16 ha of glasshouses at Huntersville. These will be the MX open roof types and will be fully automated. This will take about eight years to complete but we expect to have the first crops available in two years. By then we should have completed all the concrete floors which we can use for production. The aim is to build 4 ha of greenhouses each year afterwards until it is complete.” The aim is to have a turnover of 250 million dollars by 2025.


The philosophy held by US greenhouse giant, Metrolina Greenhouses, is to perform a little better each day. It has achieved this over the last 40 years by investing in innovation. Most of its 68 ha of glasshouses are fully automated so that human hands only touch the trays of plants when they placed in the shipping truck.

Text: Helen Armstrong. Images: Ludvig Svensson and Metrolina Greenhouses

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The ’t Hoog Bos and ’t Nieuw Bos nurseries have jointly developed an innovative watering system together with supplier Van Krimpen: the H2Obloom. This new watering system comprises a transparent vase with a click system on the inside, which provides the plant with water for 10 to 14 days. It is a unique concept, because the vase precisely fits a 12-cm cultivation pot, regardless of the supplier and the type of plant which in the pot.

H2Obloom is highly suitable for the consumer who is unable to water plants regularly, although the transparent vase is also a solution for traders and other growers. Developers 't Hoog Bos and 't Nieuw Bos use the H2Obloom vase with water reservoir to make sure their Phalaenopsis reach consumers in top condition. This idea means that plants always have enough water during the logistics process, and intermediaries do not have to take care of the plants. The innovative H2Obloom water system is available to other growers at Van Krimpen.


H2Obloom is a transparent vase with a click system and water reservoir. The click system on the inside of the H2Obloom vase keeps 12-cm pots securely in place in the vase. An important part of the system is the waterstick, an elongated thin tube, which the user inserts through one of the holes in the cultivation pot. After clicking into place, the waterstick then ends up hanging in the H2Obloom vase water reservoir. The plant can then absorb water via the waterstick, rather like drinking through a straw.

Always enough water

When the reservoir of the water system needs to be refilled, the consumer squeezes the flexible H2Obloom vase, unclicking it from the cultivation pot. The vase can then be filled with water. The system means watering is not required so frequently, and the plant never gets too much or too little water.

H2Obloom introduction

Dozens of customers from the separate nurseries ’t Hoog Bos and ’t Nieuw Bos have already had fun getting acquainted with the H2Obloom. The concept was presented to them with a bottle of Bommels Bitter, to toast the extended life promised by H2Obloom. The H2Obloom will be introduced to the general public during the Royal FloraHolland Trade Fair in Aalsmeer.

Text: Leo Hoekstra. Photo: Pull Position, Jacob Ophof.

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The winter light greenhouse aims to enhance light transmission by more than 10% during the European winter. In September a trial greenhouse of 500 m2 was prepared at a site at Wageningen University & Research in Bleiswijk, the Netherlands. Among other things it includes a special light transmitting cloth and diffuse, hydrophilic glass. “We’ve pinched a few per cent from everywhere. Our goal is to maximise the amount of light in the greenhouse between October and March.”

Even on a grey July day you had to squint your eyes when walking into the trial greenhouse during the construction work. In that respect it seems mission is accomplished. “Even the people working here say it is very light,” says project leader Frank Kempkes, researcher at Wageningen University & Research. He's been working on this project since 2014.


Kempkes organised the building together with a consortium of companies: Glascom Tuinbouw and DA Glass provided the glass; Ludvig Svensson the screen material; Bayer CropScience the most suitable cucumber variety; and Bom Group was responsible for the greenhouse and screen construction. The latter company was a logical part of the project, says its CEO Mike Vermeij. “Our company is always focused on innovation. We work closely with Wageningen University & Research on several projects. In this project too, we wanted to test our practical capability with their theoretical knowledge. Together we achieve more.”
Kempkes explains the reason for this project: “Nearly everywhere in the world natural light is the limiting factor for growth and production for part of the year. In the winter the prices are at their best. Therefore, we are searching for the ideal winter light greenhouse and a greenhouse that is also more energy efficient, because it uses more, free, solar energy."

Calculations in preliminary phase

In order to design the right greenhouse, in 2014 and 2015 researchers in Bleiswijk first looked at all the parameters. In consultation with the greenhouse designer and suppliers nine designs finally emerged. Further calculations were made using an optical simulation model created by researcher Gert-Jan Swinkels. This resulted in a greenhouse design that on paper provided 12% extra light. How? It was achieved by a combination of factors: The greenhouse construction and equipment; the glass; the screen; the screen installation; and the variety.

Larger glass panes

Starting with the greenhouse construction, it is situated east-west. This is better than a north-south position during the winter. “That is slightly less favourable in the summer but then the light is not a limiting factor. In the end you gain that back in the winter,” says the project leader.
The roof is still the ‘normal’ symmetrical Venlo roof, 5.60 m wide with extra large glass panes of 3.00 x 1.67 m. The researcher explains how this evolved. “Based purely on theory an asymmetrical saw tooth roof seemed better for the winter light greenhouse. But in practise there were disadvantages. Therefore we still went for a symmetrical roof.”
The large glass panes also caused headaches. “The disadvantage of larger glass is that it bends more. Then you need wider rods, but they intercept the light. Therefore we chose thicker glass of 5 mm instead of 4 mm. That absorbs slightly more light, but the effect is less great than wider rods."
Regarding the greenhouse construction, the upright Twinlight columns are not solid, but have a smarter, leaner, yet sturdy construction. In addition, all gutters, rods, trusses and columns are covered in a white powder coating with a reflection factor of 90%, a big improvement on out-dated aluminium that has a factor of less than 60%. “That results in just a few tenths of a percentage, but we do everything we can to achieve more light," says the researcher.

Diffuse and hydrophilic glass

The biggest gain comes from the light transmission through the diffuse glass. Compared with clear float glass – the current standard-horticultural glass – the SmartGlass used yields more than 7% extra light. A whole process was involved in its selection. First of all, researchers established that after taking measurements diffuse glass was a better choice for the crop than clear glass, even in winter. The hemispheric transmission – a weighted average of incident light taken from all angles – of this glass is more than 90% (perpendicular 96%), while that of standard glass is 84% (perpendicular 91%).
Usually diffuse glass is structured glass. In this case it is etched glass, the speciality of glass manufacturer DA Glass. Measurements showed that both types of glass performed well, as long as the glass is hydrophilic (water attractant). “Condensation always occurs on the glass in winter. If droplets form it is at the expense of light transmission. When a water film forms the transmission remains virtually the same or even increases. The type of glass produced by this supplier causes a water film to form and there is hardly any loss in light transmission,” explains the project leader.
Actually, Kempkes expects to see many more innovations in glass. “Solar panels are covered with glass. This market is growing fast so there’s a demand for improvements and therefore it continues to develop. The horticulture sector could piggyback on this.”

Better basic material for cloth

In addition to the clever construction and SmartGlass, the winter light greenhouse prototype is fitted with screens by Ludvig Svensson. These lead to at least a 4% gain in light compared with the manufacturer’s 'standard' energy screen. The greatest gain is achieved by having a better starting material. “The screen is more transparent. After testing many samples we eventually ended up with this material,” says Kempkes. Because the H2NO-technique has been applied to this energy screen the screen remains transparent even when wet from adherent condensation.
In addition to this alternative material the fitting is also special; it’s not horizontal, but forms a W-shape. “This was the screen supplier’s idea. Just like the W-shape is better for optimum light transmission through the roof, it’s the same for the screen.”
Another novelty is the Iso++ screen installation, in which two screens are about 6 cm apart. The cavity space is therefore small, so the air virtually stands still and as a result forms a good insulating layer. This is not so important for the light transmission, but it is important for the energy efficiency of the greenhouse. That also applies to the innovative dehumidifier with heat recovery, the Air in Control system by Bom Group. “We have also further optimised the forced ventilation in the greenhouse by using this system,” says Mike Vermeij.

Variety with small leaves

According to theory all these components add up to 12% extra light. The researchers are now going to accurately measure if this extra light transmission is realised in practise. The first autumn crop of cucumbers was planted at the beginning of September and will be tested. Similarly, the first winter crop of cucumbers - what the trial is really about - will be planted at the end of December.
“Together with Bayer we decided to plant Hi-Jack, a variety for a high wire winter crop. It produces smaller leaves, so that the light can better penetrate the crop. We've also tested which planting distance is best for light penetration. In this greenhouse we choose 1.86 metres in one trellis and 1.77 m in the other," says Kempkes. How the crop develops in the winter light greenhouse will be closely followed.


A winter light greenhouse has been built at the Innovation- and Demo Centre for Energy in Bleiswijk, the Netherlands. The greenhouse and screen construction, the equipment, glass and screen have been designed to optimise light transmission in the winter. The researchers, together with the participating companies, are striving for 10% extra light between October and March. A winter crop of cucumbers will be planted at the end of December. The autumn crop has already been planted.

Text: Karin van Hoogstraten
Images: Leo Duijvestijn