Both with blackberries and raspberries the demand for a year round production of good quality berries is growing. To achieve this it is necessary to use lights on the cultivation in the Dutch greenhouses during the winter, but this has not been done enough on these woody crops and the experience is therefore lacking.
As is, the growers of these crops still have many questions regarding the optimal temperature is different crop stages, the amount CO2, duration of lighting, diffuse glass, etc.. This is why a very extensive research with blackberries and raspberries under both clear as diffuse glass with light is being conducted at the Wageningen University & Research Business Unit Greenhouse Horticulture over the next couple of months. The light consists of LED-top lighting (75 µmol/m2/s) and 3 treatments with LED-interlighting with a light intensity of 75 µmol/m2/s as well. Besides a standard treatment with red/blue LEDs there are treatments with extra blue light (21%) and extra red light (13%).
It is expected that this will provide differences in, for example, crop growth, assimilation division, production, quality and possibly resilience against diseases and pathogens. Intensive measurements and observations will be conducted. Like the extensive photosynthesis measurements that will take place during the different stages of the crop and period of the day. The greenhouse trials will be conducted from mid-September 2018 till April 2019. For the blackberries the tests are done with the Loch Ness and Chester types and for the raspberries with the Kwanza and Shani. With the blackberries long preserved long canes where used and primocanes for the raspberries. Those are plants grown form cuttings.
The research is largely funded by Kas als Energiebron, with contributions by Signify (formally known as Philips), the Greenery and De Westerbouwing.
Source: Kas als Energiebron