This revision retains the same general format contained in the previous editions. The chemicals and pesticides regulations have been updated; major taxonomic changes have been made in the bacteria, fungi, nematodes and viruses; the changing picture in diseases caused by viruses and/or virus-like agents have been described. New host plants have been added, and many recently reported diseases as well as previously known diseases listed now on new hosts have been included. This book should be useful to gardeners, botanical gardens, landscape architects, florists, nurserymen, seed and fungicide dealers, pesticide applicators, arborists, cooperative extension agents and specialists, plant pathologists, diagnostic laboratories and consultants. This book should also be a useful reference book for plant pathology classrooms and in some cases used as a textbook.