Principles and Methods for Sustainable Disease Management in Rainfed Agricultural Systems

Plant diseases are a major constraint to productivity in rainfed agricultural systems. This chapter examines the nature of diseases in cropping systems, thresholds for management, major management tools, integrated disease management and the challenges for translating knowledge into practice. Inputs for disease management should be based on well-defined thresholds, but these are poorly developed for most diseases and regions. Disease management in rainfed agriculture relies mostly on alterations to crop husbandry and the use of resistant varieties; fungicide use is generally restricted to tactical application in higher value crops. Many tools such as rotation, nutrition and management of crop residues interact strongly with other components of the farm system and their effective use requires complex decisions. Much of the information required to give sustainable control of most crop diseases in rainfed agriculture is already known. There is a continuing need to convert this knowledge into forms that can be used for on-farm decision making, especially in traditional and marginal areas.