Soil has a versatile role in supporting the development of a wide range of organisms, including plants and microorganisms. Soilborne pathogens and root diseases are the primary limiting factor in many crops and tend to be very difficult to control. This first volume of a two-volume set introduces disease-causing microorganisms including oomycetes, fungi, bacteria, and viruses found in soils. It focuses on the biology, detection, and identification of soilborne bacterial, fungal, and viral plant pathogens. Volume two provides information on ecology and epidemiology of soilborne microbial plant pathogens and strategies applicable to manage diseases.  Chapters cover exclusion and prevention strategies; improvement of host plant resistance; biological management; application of chemicals; and integration of disease management strategies.