PREDICTION OF THE RESPONSE OF GREENHOUSE CROP PHOTOSYNTHESIS TO ENVIRONMENTAL FACTORS BY INTEGRATION OF PHYSICAL AND BIOCHEMICAL MODELS

Physical models for calculating the fluxes of direct and diffuse light in the greenhouse and the distribution of light in the canopy are combined with a biochemical model for leaf photosynthesis to estimate greenhouse crop photosynthesis.
The response of crop photosynthesis to light, CO₂ and temperature is calculated.

The fluxes of direct and diffuse light inside the greenhouse are estimated using data of measured global radiation outside the greenhouse and calculated transmissivities of the greenhouse cover for direct and diffuse light.

The penetration of direct and diffuse light at various points in the canopy is calculated and the rates of leaf photosynthesis in different layers in the canopy are calculated and totalled.
Account is made of reflection, multiple scattering and absorption of diffuse and direct light.

Simulated crop photosynthesis is compared with measured photosynthesis of a sweet pepper crop.
Model results correspond well with experimental results

The use of comprehensive explanatory simulation models in predicting greenhouse crop photosynthesis is discussed.

Symposium on Biological Aspects of Energy Saving in Protected Cultivation

H. Gijzen, J.A. ten Cate

https://doi.org/10.17660/ActaHortic.1988.229.25