A Diagnostic Guide for Select <i>Phytophthora</i> Species Infecting Floriculture Crops

Phytophthora nicotianae is the most important pathogen of floriculture crops worldwide, although several other species also play a significant role and include P. cryptogea, P. drechsleri, P. palmivora, and P. tropicalis. Diseases caused by Phytophthora species can be challenging to diagnose because symptoms are similar to those caused by other soilborne pathogens. This guide is intended for diagnosticians, technicians, and researchers to facilitate the diagnosis of diseases caused by species of Phytophthora on floriculture crops. Hosts, disease symptoms, molecular and morphological identification, and pathogenicity experiment methods are outlined to provide a basis for further examination of these pathogens.