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

Fundamental plant processes (e.g. leaf expansion, photosynthesis,...), envi ronmental factors such as soil characteristics, weather data, etc., cultura l practices and state-variables were coded as objects into Java classes bas ed upon agronomic theory, experimental data, and published models. The resu lt 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 an d Simulator. Environment deals with weather and soil data and computes ener gy, water and nitrogen balance in cropping systems. Plant simulates plant p henological events, height growth, as well as carbohydrate accumulation and partitioning between root and shoot systems. Input consists of plant, weat her and soil databases as well as agronomic inputs. Output draws figured an d displays text results for the state variables, respectively. Simulator is an applet which can be added into a HTML program and published on the Worl d Wide Web. It can also display a graphical user interface for the model an d manage the inputs and outputs by calling the other sub-models. This model has a graphical user interface running on the world wide web. Wi th: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, th ey may choose different environmental conditions from databases containing site-specific weather and soil characteristics, and may input agronomic dat a, such as planting date, row spacing, etc, into text fields provided by th e interface. Model output is then displayed in both figure and text forms b y clicking appropriately marked buttons for such state variables as phenolo gical events, LAT, plant height, biomass, shoot/root, photosynthesis, evapo transpiration, soil water potential, plant water stress, etc.