Originally published in 1957, as number 14 in the Agricultural Research Council Report Series, this book was created in response to serious losses in brassica crop production caused by viral diseases. The text was the product of experiments and observations carried out under a wide range of conditions in various parts of Britain. Information is provided on the causes of disease and the reaction of plants to infection, together with practical methods for controlling the spread of viruses. Illustrative figures are also included. This book will be of value to anyone with an interest in the development of farming and the history of agriculture.