Adapting lighting times: a key component of optimising the system
Maintaining the gain in radiation
From 2017 to 2021, in the trials conducted at the Balandran centre, supplemental photosynthetic lighting was applied from planting to the end of the first flush of fruit, over a 12-hour photoperiod, regardless of solar radiation. This resulted in operating costs of up to 3.70 €/m².
In 2021, the lighting periods were managed according to solar radiation (Table 1). The set radiation thresholds changed during the season and according to the time of day. The aim was to maintain a 12-hour photoperiod while reducing the duration of the LED lighting on sunny days to reduce operating costs. Short 20-minute lighting periods compensated for the loss of radiation due to the LED structure shading the plants when the LEDs were turned off.