In the Finnish situation there is typically only a limited amount of daylight available, and so a high level of supplementary lighting is applied over periods of many hours.
I was a bit skeptical at first,
but I've achieved a clear increase in production and bigger fruits.” Stefan Gulin, owner of Oy Gulin Ab
The right lighting
At first Stefan was a bit skeptical about using LED lighting: “putting more lighting into the greenhouse involves a substantial investment, so we have to calculate carefully whether it will be profitable,” he said. Stefan monitored the yield in the LED part of the greenhouse and maintained regular contact with the Philips plant specialist to discuss progress.
Stefan noted that in the 300 m2 where LED interlighting is used the tomatoes are bigger and the yield per plant is higher. This demonstrates once again LED interlighting’s X-factor, namely that more growth can be obtained from LED interlighting photons than from the same amount of HPS toplighting photons.
In this case, the plants produced an additional 1.4 times more kilos of tomato per mole of LED light photons than the control crop (kilos per mole of daylight + HPS light photons). The LED interlighting modules are also extremely energy-efficient, producing photons for only a low energy input. As a result, the extra kilos of tomatoes are produced with the lowest amount of energy/kg.