1. Terminology Pathogenicity – ability to cause disease Virulence – the degree of pathogenicity

2. Terminology Pathogenesis – series of steps that an organism goes through to cause a disease 1)Inoculation – the transfer of an inoculum from a source to an infection court degree of pathogenicity Inoculum – any part of the organism that is capable of infecting and causing disease Infection court – site on a host where infection can take place 2)Incubation – all activities (growth & development) of the organism within the infection court, including penetration into the host 3)Infection – the establishment of the organism with the host; results in the production of symptoms and formation of reproductive structures by the pathogen.

3. Signs and Symptoms Signs are the physical presence of the pathogen. Symptoms are the plants response to disease. Symptom handout