Diffuse glass and led lighting receive a lot of attention in horticulture. These techniques are expected to contribute to a higher crop production per unit of energy used. New model calculations enable prediction of the effect of different light sources on growth of a tomato crop. This is shown in a thesis on which Vaia Sarlikioti hopes to take her PhD on 10 October 2011.
A more economical use of fossil energy is one of the objectives of the horticultural sector. One of the ways to achieve this is a better utilisation of natural light or artificial light. This is why scientists of Wageningen UR Greenhouse Horticulture are working on methods for monitoring light interception of crops and for calculating the effects thereof on photosynthesis. Doctoral candidate Vaia Sarlikioti developed a 3D model for computing different light scenarios. She also investigated some sensors for crop monitoring.
Predicting effect
The model calculations of Sarlikioti gave insight into the effects of different angles of light incidence on light distribution in the crop and into the effect thereof on photosynthesis. This means that the 3D model can be used to, e.g., compute the effect of a certain extent of diffusivity of the greenhouse cover or of intercrop lighting with led lamps.
The calculations with the 3D model also provided new insights into the consequences of crop structure for light interception. A tomato plant with long internodes and long narrow leaves showed a better light absorption capacity. This means that photosynthesis can - according to the model – be up to 10% higher.
A number of sensors that could measure light interception, leaf area and plant stress on the basis of reflection were tested. The tested sensors were found to be insufficiently robust for application in practice.
Increasing interest
The 3D model has now been optimised for tomato. Wageningen UR Greenhouse Horticulture expects that such 3D models will more frequently be used in scenario studies. Such models are currently also being developed for rose and chrysanthemum.