"Last week, I saw that football club PSV had installed Philips UV lamps to disinfect the air in the locker rooms and counter corona infections. I liked to see that, a kind of confirmation that horticulture was one step ahead of those guys. We installed exactly the same lamps 3 years ago and since, we have had almost no Fusarium, and the mildew can be much better controlled. And for what it's worth, none of us has had corona."
Maarten Kramer and Aad van der Wilt
The UV blanket in the greenhouse of Aad van der Wilt is, in short, doing its job. Previously, the gerbera nursery already commissioned a UV sanitizer. Some time later - based on the idea that if it works for water, it will also work for air - the UV lamps followed. Together with Sales Manager Maarten Kramer, Aquamar, we take a look in the greenhouse in Mijdrecht.
There are 18 modules, equally spread over the greenhouse of more than 3 hectares, which is exactly sufficient, provided there's proper ventilation, to place a 'blanket' of ionized particles (which are heavier and fall down) over the crops. The modules are supplied and installed by producer Aquamar, with whom the grower has a maintenance contract. The supplier has recently changed the existing lamps for a newer, 'heavier' model.
The disinfecting function of UV lamps has been known for quite a while. In greenhouse horticulture, the technique has been used for years (particularly for roses and tomatoes). It is used in various industries and, for example in hospitals, it has been used for much longer. It is also used to decontaminate houses, second-hand cars or various utility items. Another interesting application is at the chicken farm, where it disables the famed insecticide fipronil.
The last word has not been spoken about the effect against micro-organisms. Is it possible that beneficial micro-organisms are also affected? Maarten does not want to exclude it, but, he adds, in the greenhouse you normally deal with monocultures. A result thereof is that some plagues can easily manifest in high concentrations. For humans, the particles in low concentrations are harmless, something Aad has had verified by an external party. "In the greenhouse, we measured 28 ppm, far below the legally allowed limit. I have also called with the RIVM to ask what the relation to corona is, if any, does it 'help'? They were able to confirm this."
Having said that, Maarten nor Aad consider UV to be a miracle cure. As many a grower will confirm, a better crop and higher quality is achieved by 1001 things. "Recently, I was sitting at the table with my son to put on paper the investments and improvements we have made. We came to 30 structural adjustments. UV is one of them, and it is here to stay."