An object-oriented and Internet-based simulation model for plant growth

Fundamental plant processes (e.g. leaf expansion, photosynthesis,...), environmental factors such as soil characteristics, weather data, etc., cultural practices and state-variables were coded as objects into Java classes based upon agronomic theory, experimental data, and published models. The result was a generic plant growth model for research and educational use on the World Wide Web. The model consists of several modules: Environment, Plant, Input, Output and Simulator. Environment deals with weather and soil data and computes energy, water and nitrogen balance in cropping systems. Plant simulates plant phenological events, height growth, as well as carbohydrate accumulation and partitioning between root and shoot systems. Input consists of plant, weather and soil databases as well as agronomic inputs. Output draws figured and displays text results for the state variables, respectively. Simulator is an applet which can be added into a HTML program and published on the World Wide Web. It can also display a graphical user interface for the model and manage the inputs and outputs by calling the other sub-models. This model has a graphical user interface running on the world wide web. With:a Java-embedded web browser, one can link to the run-time model from our website (http://th190-50.agn.uiuc.edu). When the users have chosen a plant genotype from the plant database to do plant growth simulation studies, they may choose different environmental conditions from databases containing site-specific weather and soil characteristics, and may input agronomic data, such as planting date, row spacing, etc, into text fields provided by the interface. Model output is then displayed in both figure and text forms by clicking appropriately marked buttons for such state variables as phenological events, LAT, plant height, biomass, shoot/root, photosynthesis, evapotranspiration, soil water potential, plant water stress, etc.