Year round blackberry harvesting in the Netherlands

G. Heijerman, L. Helmus-Schuddebeurs, C.W. van Eldik
The cultivation of blackberries (Rubus fruticosus) proves to be in control in a period with minimal outside light and the use of LED lighting in glass cultivation. In the growing season of 2017-2018 a trial was carried out at the Delphy Improvement Centre, Bleiswijk, the Netherlands, with the use of LED lighting. The plants of the black berry cultivar 'Loch Ness' were planted after a short cold period on November 20, 2017 with 208 μmol m‑2 s‑1 LED light (95% red, 5% blue), of which 120 μmol m‑2 s‑1 top light and 88 μmol m‑2 s‑1 inter light. With the usage of LED, the harvest period of blackberries was advanced to the beginning of March till the end of May. In a period of 14 harvest weeks, 6.7 kg m‑2 total production was harvested. Remarkable about the crop development was that long generative branches developed. Many side branches and fruits over the length of the crop were grown and there was little run-off at the top of the crop. Both cultivation and quality wise there is improvement necessary. That is why a new glass cultivation trial has started on September 11, 2018 with the aim to start harvesting in December 2018. The purpose of this follow-up trial was to realize a winter production, where the effect of inter lighting and light intensity on crop development are important research pillars. It was focused on maximum photosynthesis and distribution of light in the crop to achieve high fruit quality in combination with high yield. To know the most efficient lighting installation for black berries the second trial had four lighting objects: 200 μmol m‑2 s‑1 top light; 150 μmol m‑2 s‑1 top light; 145 μmol m‑2 s‑1 top lighting + 55 μmol m‑2 s‑1 inter light; 90 μmol m‑2 s‑1 top light + 110 μmol m‑2 s‑1 inter light. By reaching a production of at least 6 kg m‑2 first class fruits, this way of 'winter cultivation' for blackberries was successful. The overall goal is to develop a future-oriented, energy-efficient new growing concept for winter cultivation of blackberries in the Netherlands. The approach and complete results of this second trial will also be presented because in June 2019 all results will be complete.
Heijerman, G., Helmus-Schuddebeurs, L. and van Eldik, C.W. (2020). Year round blackberry harvesting in the Netherlands. Acta Hortic. 1277, 201-206
DOI: 10.17660/ActaHortic.2020.1277.29
black berries, Rubus fructicosus, 'Loch Ness', winter production, LED lighting, photosynthesis, energy-efficient, growing concept

Acta Horticulturae