Less Plant Stress from Cooler Leaves While Maintaining Diffuse Growth Light
With their unique strawberry drive-in, grower couple Jan and Birgitte van den Elzen from Uden gained national recognition and many new customers. Their uncompromising focus on premium quality led them to try the ReduFuse IR greenhouse coating for the first time last year. “It was a real eye-opener,” says Jan. “This coating blocks infrared heat radiation while allowing growth light to pass through in a diffused form. On sunny days, this keeps the plants cooler and helps them perform better. The staff also appreciate the more pleasant conditions.”
Jan and Birgitte were once among the larger strawberry growers in the Netherlands with three hectares of greenhouses. As the market shifted toward scale expansion, they took a different route—focusing on added value and direct consumer sales instead of “bigger and more.”
Strawberry Drive-In J&B
In 2018, the couple launched the Netherlands’ first and only drive-in strawberry shop, conveniently located near a roundabout next to their farm. It was an instant success. Providing their ever-bearing plants with the best possible conditions is a top priority. That includes protection from excessive sunlight.
“We only sell premium strawberries in our drive-in,” Jan explains. “It’s our main source of income. When fruits can ripen slowly on the plant, they grow larger, taste sweeter, and develop better color. But that requires the temperature to stay within limits.”
Crop Temperatures Often Too High
To control light intensity and avoid temperature spikes, Van den Elzen had relied for years on ventilation, fogging systems, and screens. “Those tools cooled the greenhouse quite well,” he says. “But a crop advisor pointed out that the actual crop temperature could still get quite high under intense sunlight. We started measuring—and he was right. Direct sunlight, especially through open vents, heated the plants more than I expected based on air temperature alone. That was when I realized our plants often suffered from heat stress. That means lost yield—and possibly quality.”
ReduFuse IR
Jan began to explore alternative coatings. “Chalk or ReduSol blocks too much light, but there are many other options now,” he notes. “I had a good conversation with Max Gram from Sosef Spraying Services and Paul van Gils from Lumiforte. We reviewed several options, and they recommended ReduFuse IR. It blocks infrared heat, lets PAR light through, and makes the light diffuse.”
“This has several benefits,” adds van Gils. “Infrared causes heating but doesn’t contribute to photosynthesis. ReduFuse IR effectively blocks that part of the spectrum. That’s the first win. The diffusion adds even more value.” The coating does not hinder light wavelengths useful for photosynthesis. “It lets nearly all of it through, while spreading it more evenly,” van Gils explains. “With diffused light, more of the crop participates in photosynthesis. That leads to more assimilates and higher production.”
The coating does not hinder light wavelengths useful for photosynthesis. “It lets nearly all of it through, while spreading it more evenly,” van Gils explains. “With diffused light, more of the crop participates in photosynthesis. That leads to more assimilates and higher production.” A cooler crop also means less evaporative cooling is needed—saving water and enabling more energy to go toward growth. It also reduces the amount of moisture that must be vented from the greenhouse.
*Picture provided by contractor Paul Sosef
Positive Experience
“It’s an excellent coating for light-loving crops that prefer moderate temperatures,” says Gram. “Strawberry fits perfectly.” He personally applied ReduFuse IR in spring 2024 across both of Van den Elzen’s greenhouses. “We use 20 buckets per hectare. Some apply it thinner, but at this concentration we know it lasts the full season. We’ve used it for years and most clients are very happy. We return in September with ReduClean to detach the coating so that rainfall can rinse it off.”
Van den Elzen is one of those satisfied clients. “Yes, for strawberries this is a great coating,” he says. “Staff also appreciate the milder climate and softer light. From our measurements, we’ve clearly seen that the crop stays cooler under a coated roof.”
Immediate Benefit
Asked if he sees a positive effect on production, Jan responds, “Undoubtedly, but I can’t attach numbers. Every year is different, which makes comparisons hard. Last year we had to wait long for sunny weather—but once it came, I was very glad we had the coating. This spring the sun came early. Since early April, when production picked up, we had ReduFuse IR on the roof again and saw immediate benefits. Good weather is always welcome—consumers crave strawberries and come to the drive-in. In that respect, the 2025 season is off to a great start.”