Pest identification: plant pathogens

California PCA Exam Helper: Category B

• Specific fungal diseases
• | Plant diseases caused by bacteria, fastidious vascular bacteria, and phytoplasmas


• Plant pathogenic viruses
• | Plant diseases caused by parasitic seed plants
• | Abiotic plant diseases

The list below includes all the plant pathogens contained in the knowledge expectations for the Category B California PCA exam.

Remember, in addition to knowing these organisms, there are many other knowledge expectations for this exam. Get the complete list of knowledge expectations from DPR.

Each pathogen is linked to pages within the UC IPM Web site that contain information and photos to help you identify it and understand the basic biological and management information specified in the knowledge expectations. For some pathogens, a number of links are available. If a pathogen causes disease in several crops, links are listed to the UC IPM Pest Management Guidelines for crops where it is most important. It is important to be aware of pathogens that have a broad host range, although not necessary to learn details of every disease situation. Use the knowledge expectations to determine what information you should focus on. Pathogens which are also problematic in urban situations such as gardens and landscapes are linked to Pest Notes.

Definitions for many terms can be found in the Glossary.

Information pertaining to these pathogens is also in the recommended study guide, Plant Pathology, 4th Edition, G.N. Agrios, which is a comprehensive textbook that contains much more information than you will be required to know. Always use the knowledge expectations to determine what information you need to focus on.

For each of the following pathogens and associated disease, identify:

• the common name of disease
• the genus of the causal agent
• the class of the causal agent
• the biology
• life cycles
  • the sexual structure
  • the asexual structure
  • the resistant survival stage
• host range
• signs and symptoms of the disease
• methods of control

Be prepared to identify the following pathogens when presented with a photograph, common, or Latin name.

For each of the following bacterial diseases, identify:

• the common name of the disease
• the genus of the causal agent
• the disease cycle
• means of survival
• method of dissemination
• mechanism of inoculation and infection
• environmental conditions favorable for disease
• symptoms and signs of disease
• host range
• methods of control

Be prepared to identify the following pathogens when presented with a photograph, common, or Latin name.

Be prepared to identify the following diseases when presented with a photograph and recognize the pathogen, life cycle, insect vector, and disease reservoir.

Be prepared to identify the following diseases when presented with a photograph and recognize the pathogen, insect vector, disease reservoir, and alternate hosts.

For each disease listed below, identify

• symptomology
• disease cycles
• host range
• methods of control
• how the virus is spread

Recognize the following parasitic seed plants. Know their host range and methods of control. Be prepared to identify them when presented with a photograph, common, or Latin name.

Describe the types of symptoms associated with

• herbicide injury
• mineral excesses and deficiencies
• wind
• excess soil moisture
• low soil moisture
• air pollution and other toxic chemicals
• high temperature
• low temperature
• sunscald
• edema
• etiolation

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