The addition of the far-red Philips GreenPower LED production modules enables the lettuce leaves to stretch more. The modules can be controlled separately through the GrowWise Control System. This makes it possible to add up to 12% far-red to the standard spectrum, dependent on place and time. This is especially important in the dark winter months. De Glastuin chose this because head lettuce grows in a compact way under LED. “By adding far-red, the lettuce head becomes more substantial. Larger leaves make the product look a lot more attractive,” explains De Bruyn. This also makes it easier to achieve the desired weight of the lettuce.
“We continue to pay close attention and perform tests with the amount of far-red used,” says Peer Hermans, Plant Specialist at Signify. “Adding this can also result in too much stretching.” After the installation of the full LED and the far-red modules, he continues to visit De Glastuin, optimizing the use of the modules under the various conditions, together with the grower. "That's really a win-win situation," says Hermans “Wouter is very open to suggestions. This allows us to help him with whatever he may encounter in each new situation and gives us the opportunity to learn a lot in practice.”