YAKIMA, WA – The Washington State Department of Agriculture (WSDA) has confirmed the first detection of sunflower broomrape (Orobanche cumana) in North America after a plant was discovered in Yakima. Officials say the parasitic weed poses a serious threat to sunflower crops and related industries if not quickly contained.
A local homeowner first identified the unusual plant, which was later confirmed through testing by WSDA’s State Plant Pathology and Molecular Diagnostic Lab in collaboration with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS). Both morphological and molecular analysis verified the finding.
Sunflower broomrape is a destructive root parasite that targets sunflower plants and other members of the daisy family (Asteraceae). Because it cannot photosynthesize, the weed relies entirely on its host for water and nutrients, often resulting in severe crop losses. A single plant can release hundreds of thousands of microscopic seeds capable of surviving in soil for decades, making eradication particularly challenging.
The WSDA is working with federal agencies and local stakeholders to trace the source of the infestation, assess its spread, and implement response measures. Officials warn that if left unmanaged, sunflower broomrape could cause significant economic impacts for growers, processors, exporters, and the broader agricultural economy.
WSDA is asking growers and the public to help identify possible additional introductions. People are urged not to disturb suspected plants, as this could spread the seeds. Instead, sightings should be reported by photographing the plant and contacting WSDA at pest@agr.wa.gov or calling 1-800-443-6684 (option 1). Reports should include the location, date, and photos of the suspected weed.
Native to Eurasia, sunflower broomrape is already listed as a quarantine pest in many countries because of its impact on sunflower production. The WSDA says public outreach and engagement with growers will be part of its integrated response plan as it works to contain the threat.
For more information and updates, visit the WSDA website at agr.wa.gov.
