Plant Lighting is currently researching new applications for LED lighting. Tests are being conducted with aubergines, peppers, strawberries, lisianthus and gerberas, among others. One of the aims of this research is to determine the cause of the damage to the photosystem that occurs when lighting is used for aubergines. As a result, light utilisation in winter is low and production lags behind.
This was evident from an earlier greenhouse trial in cooperation with Delphy Improvement Centre. A solution to this problem is a prerequisite for achieving successful, energy-efficient year-round aubergine cultivation in the future, writes Stefan van den Boogaart of Plant Lighting at Kas als Energiebron.
Both lighting duration, spectrum and lighting intensity as well as the interaction of these three factors were examined. This resulted in a new strategy, which is now being tested. Read more here.
These experiments showed that the longer the exposure, the greater the damage becomes to the photosystem. In addition, the spectrum also plays a determining role in the degree of damage, with a full sunlight spectrum causing less damage than a 'simple' R/B LED spectrum. In addition to these two factors, exposure intensity also appears to have a determining role in the degree Thus, when looking for a solution to this problem, both exposure time, spectrum and exposure intensity and the interaction of these three factors should be considered.
Towards a practical solution
The knowledge gained in the four trials is now being combined in two trials in a higher climate cell. In this cell the crop can be followed for a longer period of time, in order to test whether the crop continues to do well for a longer period of time in the production phase. In the climate cell, winter greenhouse conditions are simulated with sunlight simulators and supplemental lighting is provided with LEDs. For this, the researchers are using the two varieties Tracey and RZ 127. One variety is more sensitive to photosystem damage than the other. If the tests show that the developed strategy does not cause any damage and provides sufficient production, the step to the greenhouse can be made again to make the year-round cultivation ready for practice.