There is growing concern among scientists, farmers and the general public that pesticides are being applied ever more widely but with less and less discretion. This book brings together a range of experts to discuss how crop protection chemicals can be used more rationally, so as to maximise benefits in yield and quality while minimising environmental and economic costs. The book is based on the ninth Long Ashton Symposium and is organised into four sections. The first, environment, examines to what extent current pesticide use is affecting the environment and human welfare, and what changes in practice are justified. The second, application, assesses progress in performance and safety in the use of pesticides, while the next section, resistance, looks at problems and shortcomings arising from the appearance of resistant strains of pests, and considers strategies for surmounting these difficulties. The final section, forecast and pest management, asks whether existing methods of assessing risks are acceptable and seeks ways of rending decision making in crop protection more rational.

In recent decades, repeated use of herbicides in the same field has imposed selection for resistance in species that were formerly susceptible. On the other hand, considerable research in the private and public sectors has been directed towards introducing herbicide tolerance into susceptible crop species. The evolution of herbicide resistance, understanding its mechanisms, characterisation of resistant weed biotypes, development of herbicide-tolerant crops and management of resistant weeds are described throughout the 36 chapters of this book. It has been written by leading researchers based on the contributions made at the International Symposium on Weed and Crop Resistance to Herbicides held at Córdoba, Spain. This book will be a good reference source for research scientists and advanced students.

This book presents principles and practices for ecologically based weed management in a wide range of temperate and tropical farming systems. Special attention is given to the evolutionary challenges that weeds pose and the roles that farmers can play in the development of new weed-management strategies.