Diseases of Trees and Shrubs (Comstock Book) (ISBN 0801415179)

A comprehensive study of diseases and their (mis) diagnosis:
This book compiles a GREAT deal of useful information about plant pathology. It covers, as any good work about plant disease should, fertilization, nutritional deficiencies, and environmental factors such as drought, freezing, lightning, air pollution, water contamination etc. before attempting to fix the problem, the work stresses the causal effects and ,similarly, the visual pitfalls that may provide evidence of an unseen insect symptom (galling, nematodes, etc.) The work was written mainly for the temperate zone, but using it in my home sub-tropics was an eye-opener! Reccomended reading for Horticulturalists in the upper echelon, or for Pathologists as a reference, and a reminder to look to the outlying areas for an answer, It's always there!

An update that was well worth waiting for!:
Here is another one for my short list of horticulture references. As someone who makes a living looking at these diseases, let me tell you: The photos are top notch! The pictures alone tell the bulk of the story and really make this book worth it. All the latest diseases are here including Sudden Oak Death. A text like this could easily be beyond the understanding of most gardeners, but the authors use an excellent mix of common and scientific names and a wealth of descriptive text to bring things back to earth. Be a little careful making a field diagnosis from just the photos. A quick look through the book, especially the last section on physical and environmental damage, will demonstrate that a lot of things look alike. An included CD contains a complete reference list in a 333 page Word document, but nothing else. This is very useful if you are looking for more information or a specific cross-reference. My ONLY complaint is that the plants and diseases are combined into one index rather then two like the similar book "Insects that feed on Trees and Shrubs".

Invaluable:
Anybody in the plant diagnostics or pathology field must have this book on their shelf.