Rose grower, Porta Nova located in Waddinxveen, the Netherlands, produces only top-notch roses. As a company that values quality and believes in always taking new steps, they have decided to undergo new construction in 2018, adding an additional 8 hectares. The new construction will incorporate several improvements and new technologies, including Svensson’s diffusive Harmony climate screen.

Porta Nova, is an 11 hectare, soon to be 19 hectare rose operation operated by four shareholders, Leon Dukker, Nico van Vuuren,  Aad van Luik and Stefan van Vuuren who all share differing responsibilities for precise focus on all operational fronts.

The company's name, is a not just any name, it’s a name that tells a story. Porta Nova not only means ‘new port’ or ‘new door', it figuratively means ‘new step', and that’s just what the company does each and every day - taking steps to achieve new goals. "Nothing is more important to Porta Nova than quality. Everything else derives from this"  explains Leon Dukker. “We strive for only the very best, there cannot be anything better around the world.”

More diffuse light

Maintaining top-quality cultivation will become an additional challenge for Porta Nova, once the 11 hectares are expanded by 8 more hectares in 2018. The new expansion will be built on the current concept, the basis will remain the same but will include several adjustments and new additions. This will also apply to the screens that must be used for the expansion project: a light emission screen, and a Harmony screen for desired shading in the summer. It has not yet been decided which Harmony shading percentage will be selected for the new build, but it is expected that the Harmony screen will be the same shade level as in the existing greenhouse, or slightly less.

The new generation of Harmony screens have a stronger light diffusing effect, which allows for the use of a lower shade level. “You make a decision based on your experience. We prefer our current Harmony screen, much more than our previous screen. With Harmony, we have eliminated shadowing and have a higher light output. Thanks to the less harsh direct sunlight, we gain a more even crop temperature and protect the plant from stress,” tells Van Luijk. “Harmony’s diffuse light has also allowed light to penetrate deeper into the crop and with the new version of Harmony we expect an even an even greater degree of diffuse light.”

When deciding what rose variety will be grown in the new expansion selecting the proper shade level is important. “A darker rose, like Red Naomi, is less resistant to high radiation than lighter rose varieties are. If we are going to grow the Red Naomi variety in the new greenhouse, we are not sure if we will dare to use a lower shading level, however, if we decide to grow a lighter rose we will most certainly go for a lower shade level but won't make the final decision until mid-2018. Regardless of the shade level we choose - it will for sure be a Harmony screen” a satisfied Dukker testifies. “We believe that Swedish quality is the best match for us. Svensson has a long history of expertise, with years of experience and is a company that conducts a lot of research.”

More control and a better balance

The climate screen is only part of creating the perfect climate, says crop supervisor Aad van Luijk. “Good cultivation means finding an optimal balance between temperature, CO2, humidity, and light. The resources for realizing and having more control over these factors keep getting better, but there is always a weak link that you want to optimize. Harmony  provides you with more options to achieve this at lower daytime temperatures, thanks to its high light diffusivity. You can maintain a cooler climate, while still allowing in sufficient light during the summer creating top-quality conditions.”

Optimal options

When you look at the greenhouse, it’s clear that Porta Nova has carefully considered the best options for optimizing their climate. The Klimrek water buffers located underneath the four roofs provide constant control of water quality are not visible. And when you look up, you see that light levels are optimized using lamps and Svensson’s  light-diffusing Harmony screen.  Porta Nova’s Harmony and blackout light pollution screen operate on one wire bed. “We don’t need additional wires when using two different screens.”

Heat exchangers absorb the excess heat when the sun provides sufficient warmth in the greenhouse. These heat exchangers absorb the heat and return it to a one hundred meter deep aquifer through a heat pump. The aquifer is very stable, resulting in a great degree of efficiency and sufficient heating for the greenhouse during cold winter months.

his article was featured in the September 2017 issue of KAS magazine.

Porta Nova is an amalgamation of three family businesses. The foundation was laid in 2002 by Leon Dukker and Nico van Vuuren, with Aad van Luik and Stefan van Vuuren later joining them in 2007. They have exclusively been growing roses from the start and only grew one variety, the passion rose until 2006 when they began producing the Red Naomi, a strong, deep-red rose.