Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V58

Effect of LED lighting and increased temperature on yield of winter grown strawberries

Höfundar / Authors: Christina Stadler

Starfsvettvangur / Affiliations: Landbúnaðarháskóla Íslands

Kynnir / Presenter: Christina Stadler

The use of LED instead of high pressure sodium (HPS) lights reduces electricity costs. From previous experiments it is known that the harvest of strawberries was delayed by two weeks under LED lights. This was possibly attributed to a lower leaf and soil temperature under LEDs and a lower air temperature compared to the HPS treatment with its additional radiant heating. Therefore, it should be tested if it is possible to avoid the delayed harvest by using a higher temperature under LED than under HPS lamps.
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 October 2018 to the middle of January 2019. The plants were lighted with high-pressure vapour sodium lamps (HPS, 269 µmol/m²/s) or under LED lights (278 µmol/m²/s) for a maximum of 16 h light. The temperature was 19 °C (LED) 16 °C (HPS) / 8 °C (day / night) and 800 ppm CO2 was applied. Fruits were regularly harvested and classified.
When the day temperature was set three degrees higher in the LED treatment to reach a similar leaf temperature as in the HPS treatment, the strawberries developed flowers earlier. Thus, strawberries under LEDs with increased temperature were one week earlier ripe than under HPS lights. At the end of the harvest, the marketable fruit yield of Magnum was significantly higher under HPS than LED lights due to tendentially more marketable fruits and a tendentially higher average fruit weight. However, with Sonata there were no yield differences found between lighting sources.
It was concluded that additional heating under LED, compared to HPS lights, prevents delayed harvest of strawberries. However, a lower yield under LEDs is possible.