In some countries a network is part of the basic equipment of a greenhouse, but this is not the case in the Netherlands. However, this trend is changing recently, as Marcel Schulte and Maarten, van Hagen from Holland Gaas have noted. Recently, two major chrysanthemum growers – Linflowers (new 7.1 hectare greenhouse) and U-Grand (new 10 hectare greenhouse) – have decided to use mesh, and besides the two examples given, there is much greater interest in mesh .
Marcel Schulte and Maarten van Hagen
“Basically, the main arguments against the use of mesh have passed,” say both Marcel and Maarten, “and there are two reasons for that. On the one hand, the use of chemicals is no longer allowed as it used to be. Instead of spraying unwanted visitors in the greenhouse, newer strategies are more often aimed at preventing them from even entering. It already happened in biology and these are natural enemies that you want to keep inside. Second, Het Nieuwe Telen (HNT) has reached new heights, which in practice means that the windows in the greenhouse are opened less often. The screens are used extensively and with a higher humidity, people can now cultivate with a higher internal temperature. “
Inside and outside
The use of mesh has been the standard for seed growers for many years. Plant breeders soon followed this trend, and recently more and more production farmers have followed suit. For example, interest in meshes in tomato growing has increased since the arrival of ToBRFV, notes Maarten. “Nothing is allowed to get into the greenhouses, but birds and bees can simply fly in through the windows. That makes you think. “A similar thought can be seen across the horticultural sector, but another aspect comes into play in the ornamental sector. “Your greenhouses are never empty for a great clean. Because of this, the insects inside cannot be easily removed. Because of this, it’s not uncommon for things like growing roses to be intertwined. “
A rise in floriculture
If not in chrysanthemum cultivation. Holland Gaas may have done various projects in the past, including one at Kester Tuinbouw in 2003 – which was reportedly to their complete satisfaction – but they were still just exceptions. So far, in addition to the breeders already mentioned and a large number of tests – including one at Denim Flowers and The Perfect Chrysanthemum in Delphy’s greenhouse – the benefits of mesh have been increasingly noticed. “New findings in cultivation contribute to this. For example, a producer would like to be able to ventilate his cultivation, but given the conditions in the Netherlands, the maximum airtime for the producers would only be a few weeks per year. Occasional ventilation is often sufficient. Let’s say you have a ventilation reduction of 20% and want to open the windows to around 50%. Then you can also increase this to 70%. “
Existing or new greenhouses
Depending on the situation and the mesh size chosen, users can choose between larger or even more windows for ventilating new greenhouses. Loss of ventilation is not a problem in this case. However, with existing greenhouses, installers often find that the capacity of the windows is not being used to the full because the windows do not open fully. This is of course a waste of ventilation capacity, but it can often be easily remedied by adjusting the system settings.
System application
“We have not yet found a greenhouse in which it was not possible to install a mesh system. Together with greenhouse builders, system suppliers and / or our own installers, our engineers have always found ways to design profiles that allow the mesh systems to be installed, ”says Marcel. “Sometimes people wonder if such a system might be too heavy to build, but this was never a problem even during an installation.”
accordion
Holland Gaas can call himself the inventor of the current accordion system and has refined this system over the years. People have also made production more professional and uniform over time. A constant mesh size is important, for example, to keep a certain insect out. Thanks to the improvements to the polyester wire, the net has also become a more sustainable product overall. On the third floor of the office building, the company is constantly researching strength, weather resistance, wear and tear, diffusivity, flexibility and much more in order to obtain the best possible product. Many of the implemented improvements were developed and extensively tested right here.
For more informations:
Holland gauze
Hundertland 30
2676 LS Maasdijk
info@hollandgaas.nl
www.hollandgaas.nl
