Models in Crop Protection

A plant disease model is a simplified representation of the relationships between pathogens, crops, and the environment that cause the development of epidemics over time and/or space. This chapter describes the different modelling approaches, focusing on fundamental (process-based) models for application in crop protection. The development of process-based dynamic models consists of four steps: (i) definition of the intended use of the model; (ii) conceptualization of the system; (iii) development of the mathematical framework; and (iv) model evalua- tion. Plant disease models now have a key role in supporting the decision-making process in integrated pest management (IPM). The advantages of using models in IPM are linked to their ability to process and analyze complex information and to provide outputs supporting decision-making at strategic and tactical levels. In particular, simulation models can support strategic decision-making, and predictive models can assist growers in making tactical decisions. Finally, the chapter briefly considers how different models can be combined with the aim of helping growers to make correct and objective decisions about crop protection.