THE APPLICATION OF LEDS AS ASSIMILATION LIGHT SOURCE IN GREENHOUSE HORTICULTURE: A SIMULATION STUDY

The application of light-emitting diodes (LED’s) as potential source for assimilation lighting in greenhouse production systems opens up a range of new possibilities.
LED’s produce light in a very narrow wavelength range and do not directly emit heat radiation.
The heat which is produced by LED’s due to their limited energy conversion efficiency, can be drawn away via convective (water)cooling.
As a result, LED’s can be applied at relative dark places within the crop to increase leaf photosynthesis at locations where assimilation light normally doesn’t penetrate.
In theory this type of intercrop lighting could significantly increase crop photosynthesis.
Existing simulation models for greenhouse/crop systems can be used to simulate the potential effects this intercrop lighting on crop photosynthesis.
It is unclear however, whether the assumptions and simplifications that are justified in present crop models cause problems in simulations of growth systems with intercrop lighting.
It may be anticipated that photosynthetic capacity of leaves that are subjected to intercrop lighting adapt different than leaves that are subjected to top lighting by natural light and assimilation light only.
In this simulation study we investigated the sensitivity of leaf photosynthesis to adaptation of leaf photosynthetic components at different CO₂/light combinations, using the widely used steady-state model of Farquhar et al. (Planta 149: 78–90, 1980) for photosynthesis.
The results are used to discuss limitations of current crop photosynthesis models to simulate production in greenhouse systems with intercrop lighting.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

W. van Ieperen, G. Trouwborst

greenhouse crops, interlighting, intercrop lighting, simulation model, light-emitting diode (LED)

https://doi.org/10.17660/ActaHortic.2008.801.173