Institute of Ecology and Resource Management, School of Agriculture, University of Edinburgh, West Mains Road, Edinburgh EH9 3JG, Scotland, United Kingdom
Data obtained by sampling are crucial for decision making in crop loss assessment and pest management. Such data improve farmers' perceptions of the threat of pests and can, therefore, improve the quality of decision making in the practice of crop protection. The concept of a threshold, representing the dividing line between two alternative courses of action relating to seed or crop health, is an important aspect of crop protection decision making. Sampling is the means by which the required judgment can be guided. Operating characteristic curves are an important tool in the evaluation and comparison of the performance of sampling schemes. Precision integrated pest management, in which the objective is spatially variable pest management within fields, poses new problems for decision makers and statisticians developing sampling methodology in the context of crop protection.