Preliminary Course.
Plant and crop Models
PBM (3)
Pros and cons of process-based models
Process-based model advantages
* This modular approach makes the development of such a model easy and flexible
* For given environmental conditions, such a model has proved to be efficient on many crops
* Field measurements, calibration and validation are quite easy, since they are limited to few parameters
Process-based model limitations
* The LAI, required as an input, is usually not easy to simulate
* Variations in the harvest index cannot be easily controlled. Specific variations due to the plant structure cannot be distinguished from those due to stresses effects (water, light). Conversely, stresses are difficult to relate to harvest indexes
* Stochastic behaviour cannot usually be considered; mean production values can be assessed, but without variances
* Organogenesis is implicit, since organs are considered as compartments. Hence organ differentiation and abortion prediction are difficult
* Problems in linking different modules together (development is often unconnected from the growth)
* Girth growth (secondary growth) is often ignored
* The approach suffers from a lack of genericity, often requiring specific developments when trying to switch from one crop (species) to another
* Structure is ignored, hence 3D representation enabling their applications: visualization.