Biocontrol refers to a method of managing plant diseases and pests through other organisms. Diseases in plants are caused by pathogens and environmental conditions. Biocontrol deals with the control of pathogens such as fungi, bacteria, viruses, protozoa and viriods. It depends on natural mechanisms like predation, parasitism and herbivory. The main strategies which are used within biocontrol are augmentation, importation and conservation. In augmentation, a large number of natural pathogens are administered for quick pest control. Importation is a method where a natural enemy of a pest is brought for controlling pests. Conservation relies on measures which are aimed at maintaining natural enemies by regular reestablishment. This book elucidates the concepts and innovative models around prospective developments with respect to biocontrol of plant diseases. It is compiled in such a manner, that it will provide in-depth knowledge about the theory and practice of this field. This textbook is appropriate for those seeking detailed information in this area.