Strawberry plants grown in the fall under light-emitting diodes (LEDs) produce more fruit that taste better and have more vitamin C compared to those grown using different lighting systems, according to research from Wageningen UR’s Greenhouse Hortriculture department funded by Philips.

Five varieties of strawberries were planted on Aug. 20 in a greenhouse of IDC Flavour at Wageningen UR Greenhouse Horticulture in Bleiswijk, and grown under three lighting systems.

LEDs were positioned to illuminate mainly the leaves or the fruit. The lighting period started with 14 hours a day and later decreased to 10 hours. Additionally, LED lamps were used at the top of the greenhouse. From week 41 on, the lights were on depending on the radiation and instantaneous radiation.

Early results show that strawberries taste better under additional lighting on the leaves or fruit. This effect was seen especially from the beginning of November. The fruits were sweeter, more aromatic and scored high on fruitiness. Also, the instrumentally measured refraction and acidity increased.

Although strawberries normally have a high vitamin C content, lighting enhanced this antioxidant. Production was increased by about 15 percent by the end of November due to the additional lighting. Interestingly, there was little difference in effect on fruits between the leaf and fruit exposure, while relatively much light falls on the ground with the latter method.

As is commonly known, there are large differences in taste between varieties. Darselect and Sonata score higher in taste than Elsanta and FF1203. This was also reflected in the ratings by taste experts from the various flavor characteristics. The vitamin C content of Sonata is 30 percent lower than Elsanta.

The intention is to continue with these plants in the IDC Flavour in the spring.