The big challenge in growth light trials with tomatoes is achieving the highest possible yields, and that requires extensive research knowledge and practical growing experience. The trials aim to combine the most advanced climate control and led grow light technologies and also serve as demonstration areas.

In the 2013/2014 growing season, a trial with RYGH GreenPower LED toplighting and interlighting was set up in one section. This trial involved three lighting set-ups which produced a combined light level of 210 μmol/m2/s. Crops in set-up 1 received toplighting alone, crops in set-up 2 received toplighting and a single line of interlighting, and crops in set-up 3 received toplighting and two lines of interlighting

Unlike the previous trial, the follow-up trial used pinched grafted plants instead of one-on-onegrafted plants? The spacing was 4.2 stems per square meter. This resulted in 97.1 kg/m2 with a limited watering regime and 100.6 kg/m2 with a standard watering regime

By far, the biggest advantage of the LED toplighting and interlighting combination compared to HPS lighting is the fact that the light penetrates deeply into the crop. This allows both the leaves and the fruit to receive enough light for strong growth. Adviser Willem Valstar, who managed the trial says, “With full LED we can optimally steer the lighting and plant temperature, so the plant does not experience unnecessary stress and thus grows better. The climate also remains more stable and the CO2 is used more efficiently.”

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