Screening questions to determine the need to submit
a plant sample for Phytophthora ramorum testing
The pathogen P. ramorum does not travel well by wind or air currents. The most likely pathway for introduction to Illinois is on infected nursery stock. When determining if a plant could potentially be infected with P. ramorum, these are some helpful questions to keep in mind:
- Was the symptomatic plant purchased after 2002, or is it near a plant that was purchased after 2002?
- Is the affected plant a host for P. ramorum? (please refer to the current list of hosts and associated hosts for this pathogen)
- Does the plant show symptoms consistent with infection by P. ramorum? (please refer to pictures of P. ramorum on various hosts)
- If the affected plant is in the oak family (red oak, pin oak, beech, chestnut, chinquapin) look for bleeding from the bark without wounds, crack, or insect holes.
- If the affected plant is not in the oak family, look for dark brown, oval spots on leaves, dark brown tip dieback on leaves, defoliation (usually from the bottom up), and/or stem or branch tip dieback.
- If you answered "no" to one or more of the above questions, the affected plant is unlikely to be infected with P. ramorum. A sample can be submitted to the University of Illinois Plant Clinic for a general diagnosis to determine if a pathogen or insect pest is causing the symptoms. For more information about the Plant Clinic, including how to submit a diagnostic sample, please see their website: http://web.extension.illinois.edu/plantclinic/
- If you answered "yes" to all of the above questions, the affected plant could potentially be infected with P. ramorum. Please contact the University of Illinois Plant Clinic at 217-300-0519 or at plantclinic@illinois.edu. Photographs of the symptoms can be emailed to the same email address.
- Because P. ramorum is regulated, samples suspected of being infected with this pathogen must be submitted to federally-designated plant diagnostic laboratories. The University of Illinois Plant Clinic is the only federally-designated plant diagnostic laboratory in Illinois. Please call ahead of time if you are planning to submit a suspect sample.
Information on other plant diseases and disorders is available through the University of Illinois (ipm.illinois.edu/diseases/#600)
Direct questions to the University of Illinois Plant Clinic , 217-333-0519, or visit the Plant Clinic web site at http://plantclinic.cropsci.illinois.edu
