As agricultural production increases to meet the demands of a growing world population, so has the pace of biotechnology research to combat plant disease. Diseases can be caused by a variety of complex plant pathogens including fungi, bacteria, viruses and nematodes, and their management requires the use of techniques in transgenic technology, biochemistry and genetics. While texts exist on specific pathogens or management practices, a comprehensive review is needed of recent developments in modern techniques and the understanding of how pathogens cause disease. This collection of studies discusses the key approaches to managing each group of pathogens within the context of recent developments in biotechnology. Broad themes include microbe-plant interactions, molecular diagnostics of plant pathogens and enhancing the resistance of plants.