Epidemiology of Phytophthora ramorum infecting rhododendrons under simulated nursery conditions

The current understanding of diseases caused by Phytophthora ramorum and their dynamics in nursery crops is almost entirely derived from casual field observations. The objectives of the study are to help understand basic biological factors such as, inoculum viability, dispersal, and infectivity that influence disease occurrence and severity in a rhododendron nursery. The experiments were conducted under conditions that simulate a commercial containerized rhododendron nursery regime in the central coast of California. This extended abstract presents information on the findings of the first year of a two-year study.