Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017
Erindi/veggspjald / Talk/poster V67
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, the harvest period of icelandic strawberries is from May to October and therefore, there is no supply of icelandic strawberries in winter and spring. However, there is also a demand on strawberries in those months with low levels of natural light and thus are foreign strawberries imported. Therefore, it was tested if it is possible to grow strawberries in winter in Iceland and how the yield of strawberries is influenced by the light intensity.
In the research greenhouse of the Agricultural University of Iceland were strawberries (Fragaria x ananassa cv. Sonata) with a plant density of 12 plants/m² (4 plants / 5 l pot) grown. The plants were lighted with high-pressure vapour sodium lamps (HPS) for a maximum of 16 h light. Two different light intensities were tested, 100 W/m² and 150 W/m². The temperature was 16 °C / 8 °C (day / night). Bumble bees were used for pollination. Fruits were regularly harvested and classified.
Marketable yield of strawberries increased with a higher light intensity. The yield increase was attributed to more fruits, while the average weight was not affected. It seems that more light (150 W/m²) resulted in more flowers. However, this effect was less pronounced at the latter part of the growing period. This might be connected with a higher natural light level at harvest (from middle of March to beginning of May).
It is recommended to use a higher light intensity to have a positive effect on yield. However, with increasing natural light level, a higher light intensity is less important and could possibly be decreased to save energy costs.