Willem Hendriks, Maison L’Oasis:
"Glass greenhouse in Tunisian desert was conscious decision"
"The glass greenhouse was a conscious decision," says Willem Hendriks, director of Maison L'Oasis. Contrary to other projects in Tunisia, he chose to have a "glass Venlo greenhouse" built, and opted for diffuse toughened glass. The choice is based on more growing light in winter, as well as a long-term vision. While plastic needs to be replaced every three years, the glass greenhouse has a longer lifespan.
For a long time, the diffuse nature of plastic was a major advantage over glass. Now this can also be applied to glass, and a lot of experience has been gained with diffuse glass in similar climates, like the US, Australia, and the Gulf region. North Africa didn't have that experience yet.
"We also considered it very important for the greenhouse to be completely closed off to insects," Willem says. "Plastic is more susceptible to getting holes. With the installation of insect screens in the ventilation windows, we succeeded, and we notice the pressure from pests is very low. It's still far too early to answer the question whether glass is a better choice than plastic. We'll see that in the coming years."
Construction time was relatively short. In early March, the foundation was laid, and planting was able to begin on September 1. With a short construction period in Tunisia, it's very important for the installers and builders to communicate well with each other and cooperate intensively. Havecon Projects had the role of principal contractor, and under this management VB and PB tightly planned and executed the entire project. With this partnership between the three Dutch parties, the planning was never at risk for a single moment.
Such a construction project is tough, however. "The weather has been particularly adverse in recent months. During the day, it's around 40 degrees Celsius outside, and at night it's also often over 30 degrees. This means that during the daytime, temperatures in the greenhouse rise to over 50 degrees, which means working at night really is the only option," according to the builders. "Still, everything was finished right on time."
Cultivation
Hendriks: "The start of cultivation is very difficult here. Warm days, and especially at night the temperature remains very high, around 25 to 30 degrees. In October, the night temperature goes down, and things are easier. Production is going well, and the taste and quality is really very good. Fortunately we don't need much time to distinguish ourselves from the other large tomatoes in winter, which mainly come from unheated greenhouses in Morocco."
For more information:
Havecon Kassenbouw B.V.
Marconistraat 32
2665 JE Bleiswijk
Postbus 25
2665 ZG Bleiswijk
The Netherlands
Tel. +31(0)10 266 32 70
Fax +31(0)10 266 32 71
[email protected]
www.havecon.com