This guide provides descriptions and photographs of the more common tomato diseases and
disorders worldwide. For each disease and disorder the reader will find the common name, causal
agent, distribution, symptoms, conditions for disease development and control measures. We have
also included a section on common vectors of tomato viruses. New to this guide are several bacterial,
virus and viroid descriptions as well as several tomato disorders. The photographs illustrate
characteristic symptoms of the diseases and disorders included in this guide. It is important to note,
however, that many factors can influence the appearance and severity of symptoms. Many of the
photographs are new to this guide. We are grateful to the many academic and private industry
individuals who contributed photographs for this guide.
The primary audience for this guide includes tomato crop producers, agricultural advisors, private
consultants, farm managers, agronomists, food processors, and members of the chemical and vegetable
seed industries. This guide should be used as a reference for information about common diseases and
disorders as well as their control. However, diagnosis of these diseases and disorders using only this
guide is not recommended nor encouraged, and it is not intended to be substituted for the professional
opinion of a producer, grower, agronomist, plant pathologist or other professionals involved in the
production of tomato crops. Even the most experienced plant pathologist relies upon laboratory and
greenhouse techniques to confirm a plant disease and/or disease disorder diagnosis. Moreover, this
guide is by no means inclusive of every tomato disease. Rather, we present those diseases that are
currently most prevalent worldwide in protected culture and open field productions.
Always read and follow label directions for any herbicide, fungicide, insecticide or any other chemical
used for treatment or control.
A glossary of words used in the text can be found at the end of this guide along with a list of references
for additional information on the diseases and disorders addressed within this publication.