Plessey lights make more tomatoes

The seven-month trial, managed by Plessey head agronomist Maarten Klein (right), ran from November 2016 at Gebr Koot in the Netherlands.

Brioso variety tomatoes were illuminated by either 150μmoles/s/m² of HPS or the same, but with an extra 58μmoles/s/m² of Plessey LEDs.

“By the end of the trial, an extra yield of 9.4% (3.28kg/m²) was achieved with a slight increase in average weight per tomato for the hybrid LED/HPS installation compared to the control area with HPS lighting alone,” said Plessey. “The increase in yield was possible because the plant load allowed more fruits per truss without losing plant strength. It is likely even higher yields are achievable by increasing greenhouse temperatures to take advantage of the increased potential in the crop.”

According to the firm, adding LED light fixtures to existing HPS lighting system allows greater light intensity to the crop, for longer periods, with little extra heat to manage in the greenhouse.