Strawberries taste better when they are illuminated in the autumn with LED grow lights, vitamin C content also increased as well, according to a Dutch research institute.

The strawberries were planted on Aug. 20, 2014 in a greenhouse of IDC Flavour at Wageningen UR Greenhouse Horticulture in Bleiswijk, Netherlands. Three lighting systems and five different varieties were being demonstrated in the greenhouse there, starting in week 39.

LED lights are positioned just above the plants illuminate mainly the leaves (leaf lighting) or LEDs illuminate mainly the fruits (fruit lighting). The lighting period started with 14 hours a day and later decreased to 10 hours. Additionally, LED lamps are being used at the top of the greenhouse (toplight). From week 41 onwards, the lights were on depending on the radiation and instantaneous radiation.

Strawberries basking under LED grow lights at Wageningen UR Greenhouse Horticulture in Bleiswijk, Netherlands. (Photo credit: Wageningen UR Greenhouse Horticulture)

Better taste and higher strawberry yields

Initial 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, strawberry fruits normally have high vitamin C content, lighting enhanced this antioxidant. Production was increased by about 15% 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.

Large differences in taste strawberry varieties

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% lower than Elsanta.

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

This project was sponsored by lighting giant PHILIPS.