A review of the current methods used to detect Phytophthora cinnamomi

Worldwide, Phytophthora cinnamomi is one of the most devastating plant pathogens. It infects almost 5000 plant species, causing death and habitat loss. There is a need for improved monitoring and management strategies to prevent the spread of this plant pathogen. The methods used for detection and identification have been established, but there are many variations depending on the species of Phytophthora, resources available, limitations of time and laboratory protocols, including previous knowledge or specialists involved. This review examined papers published from 2011 to 2025 that describe methods used to detect P. cinnamomi from environmental samples. Sixty-one papers were identified and included in this review. Collectively these papers showed that sampling approaches can include either direct sampling of soil, roots, plant tissue, and water, and indirect sampling by environmental baiting. Detection methods then can contain up to three main processes, including baiting, culture-based detection and isolation, and molecular confirmation. The sampling and detection methods identified in this review were used to develop a decision making flowchart that will help future researchers and management to choose the most appropriate methodological approach to identify P. cinnamomi from the environment. The flow chart presents methods based on laboratory time; resources available; and the type of sample collected. This information will increase the reliability of detection and improve the allocation of resources. This ultimately will improve the monitoring of P. cinnamomi to determine the spread of the pathogen, and to evaluate different management and control strategies to minimise its spread and impact on native vegetation, agriculture, forestry and horticulture.