This book is a response to the increasing interest in biological control of plant diseases which is being shown by academic, commercial and agricultural organizations, and individuals, all over the world. The subject now receives more than a brief mention in most courses taught on plant pathology and is clearly going to be more important in the future. The excellent books by R. J. Cook and K. F. Baker will remain the standard references and there are now many review articles on various aspects in specialist journals. The present text attempts to provide an account of biological control of plant diseases that will be suitable for undergraduate students at college or university who will be meeting the subject for the first time. It is hoped that teachers at other levels will find it useful and that it will help research workers in many fields to enter the literature on disease control through biological means. The two introductory chapters attempt to set out general principles of microbial, host and pathogen interactions, and the historical and commercial background to biological control. The glossary is not comprehensive, but is designed to help those with a limited background in plant pathology and ecology.

There is a great deal of information produced for and by the agricultural industry on the chemical means of controlling diseases, as well as a vast research and teaching literature. Hopefully this book will provide some readily available information and examples of biocontrol. I by no means disparage the enormous benefits that have resulted from the correct use of pesticides, especially fungicides so far as we are concerned, but there is now a need to present a balanced argument for and against different methods of disease control.