Decision Making in the Practice of Plant Disease Management

In the practice of disease management, the challenges faced by decision makers are many and various. We outline two approaches to evidence-based decision making that have application in disease management. First, sampling as a basis for decision making is discussed. The purpose of sampling is to gather information on disease intensity. This information is the evidence on which a decision about the need for some appropriate control action can be based. Sampling a crop for the purpose of deciding whether or not treatment is required entails classification of observed disease intensity in relation to some pre-specified critical intensity (threshold). This is not the same as sampling a crop for the purpose of estimating disease intensity. The theory of sampling for the purpose of classification has been developed most extensively in the area of statistical quality control. In this chapter, we concentrate our discussion on methodology for sampling disease incidence data, because sampling for counts is already so widely discussed in the economic entomology literature. Chapter topics include: Decision Making in Disease Management Acceptance Sampling Preliminaries Designing a Sampling Plan with a Specified Curve Zero Acceptance Number Sampling Plans Sequential Sampling for Classification Risk Algorithms as a Basis for Decision Making Predicting the Need for Treatmen