Plant diseases constitute one of the major causes of crop losses all over the world. Detection of diseases in plants is critical for sustainable agriculture. The unique feature of this book is the compilation of research papers and review articles written by internationally recognized plant pathologists and microbiologists. In this volume we describe modern and conventional techniques for the detection of plant pathogenic fungi, viruses, viroids, bacteria, mollicutes and nematodes. Future prospects of each diagnostic technique and current literature are also discussed in detail. It also compares the benefits and limitations of some potential techniques. This review should be of particular value to scientists in the developing world, who may not have ready access to the special journals and reports in which much of the research on diagnostic techniques has been documented. It is our hope that diagnosticians and research scientists will find this information useful as well as thought provoking.