Modelling systems of disease and yield loss in cereals

Abstract

Efforts to develop reliable models for predicting crop yield loss due to diseases have increased in recent years, in response to the demands for disease management and for resource allocation for research and extension. This paper outlines the statistical and physiological criteria that should be considered during the development of such models. Case studies from the literature are examined and discussed in relation to their use in providing regional crop loss estimates. A conceptual response surface of cereal yield loss to disease constraints is proposed and suggested as a guide for future disease-loss modelling. The limitations of empirical data for response surface models are illustrated using a barley leaf rust system.