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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Disease and Pest Management Research Unit » Research » Publications at this Location » Publication #382273
Research Project: Development of Knowledge-based Approaches for Disease Management in Small Fruit and Nursery Crops

Location: Horticultural Crops Disease and Pest Management Research Unit

Title: The challenges of managing phytophthora root rot in the nursery industry

Author
item Weiland, Gerald - Jerry

Submitted to: Plant Health Progress
Publication Type: Review Article
Publication Acceptance Date: 4/19/2021
Publication Date: 9/12/2021
Citation: Weiland, G.E. 2021. The challenges of managing phytophthora root rot in the nursery industry. Plant Health Progress. 22:332-341. https://doi.org/10.1094/PHP-02-21-0036-FI.
DOI: https://doi.org/10.1094/PHP-02-21-0036-FI

Interpretive Summary:

Technical Abstract: For nearly 100 years, Phytophthora root rot (PRR) has been a severe problem in nurseries. Early surveys found only one or two Phytophthora species on any one host. However, recent surveys show that nurseries are impacted by increasingly complex Phytophthora communities that vary by host, nursery, and region. Individual community members have diverse biological characteristics and differ in their response to disease control measures. These differences may shift community composition towards members that are less sensitive to treatment, thereby decreasing overall disease control. Together, this suggests that PRR is better approached as a disease complex rather than as a disease caused by a single entity. Yet, most experiments use only a single Phytophthora isolate and are therefore unable to account for the responses of other community members. Successful control is further limited by a lack of data on the disease losses and soilborne inoculum levels encountered in the nursery industry, which are essential for establishing risks for infection, pathogen movement, and for evaluating disease control efficacy. Focused surveys with intensive sampling are needed to better characterize the Phytophthora communities occurring on major nursery crops. Experiments should utilize a representative set of species and isolates to ensure treatments are effective. The presence of diverse Phytophthora communities in the nursery industry makes it less likely that any one disease control tactic will be broadly effective. Instead, a combination of approaches that take into account the individual weaknesses of each community member will likely be necessary to achieve long-term PRR control.