Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V59

Effect of LED lighting on yield of winter grown strawberries

Höfundar / Authors: Christina Stadler

Starfsvettvangur / Affiliations: Landbúnaðarháskóla Íslands

Kynnir / Presenter: Christina Stadler

The extremely low natural light level is the major limiting factor for winter glasshouse production in Iceland. Therefore, supplementary lighting is essential to maintain year-round production. So far, strawberries are lighted with high-pressure vapour sodium lamps (HPS). However, due to the fact that the electricity costs are contributing much to the total production costs, are ways to reduce lighting costs requested. Therefore, it was tested how the yield of strawberries is influenced by LED lights.
In the research greenhouse of the Agricultural University of Iceland were strawberries (Fragaria x ananassa cv. Sonata and cv. Magnum) with a plant density of 12 plants/m² (4 plants / 5 l pot) grown from the beginning of December 2017 to the beginning of April 2018. The plants were lighted with high-pressure vapour sodium lamps (HPS, 277 µmol/m²/s) or under LED lights (279 µmol/m²/s) for a maximum of 16 h light. The temperature was 16 °C / 8 °C (day / night) and 800 ppm CO2 was applied. Fruits were regularly harvested and classified.
The development of the flowers and the harvest was delayed by two weeks under LED lights. This was possibly attributed to a lower leaf and soil temperature under LED lights and a lower air temperature compared to the HPS treatment, where HPS lights contributed to additional heating. On the other hand were the strawberries in the LED treatment benefited by increased solar radiation due to the longer growing period of two weeks. At the end of the harvest period was the weight of the marketable yield independent of the light source.
From an economic viewpoint it is so far not recommended to replace HPS lamps by LED lights. More scientific studies are needed with different temperature settings to compensate the additional heating by the HPS lights and the delayed growth and harvest.