Destructive sunflower root parasite confirmed in Yakima. It is the first detection in North America

The first known occurrence in North America of a devastating root parasite that affects sunflowers has been confirmed in Yakima, state agriculture officials reported.

Orobanche cumana, commonly known as sunflower broomrape, is a destructive and highly invasive parasitic weed. It was discovered by a Yakima homeowner, according to the Washington State Department of Agriculture. The agency said it was the first-ever North American detection.

Identification was confirmed by the department’s State Plant Pathology and Molecular Diagnostic Lab and USDA Animal and Plant Health Inspection Service, according to a news release.

Sunflower broomrape is incapable of photosynthesis and relies entirely on the host plant for water and nutrients, officials said. It has the potential for significant crop losses in sunflowers and other members of the sunflower family.

Native to Eurasia, sunflower broomrape is a quarantine pest in many countries due to its devastating impact on sunflower production. Although it attaches to the host plants’ roots, it produces distinctive above-ground, leafless flower stalks.

A single plant can produce hundreds of thousands of microscopic seeds that remain viable in the soil for decades, making eradication difficult once established, the release said.

“This detection is especially concerning due to the aggressive nature of this parasitic weed and its potential to spread rapidly if left unmanaged,” he release said. “Sunflower broomrape poses a serious threat to commercial sunflower production and could cause significant impacts to growers, processors, exporters and the agricultural economy if not swiftly contained.”

State agricultural experts are working with federal and local officials to investigate the source, assess the extent of the infestation and respond, officials said.

If you suspect you have seen sunflower broomrape, don’t disturb it; that may cause the seed to spread. Instead, photograph the suspected plant and report it immediately.

Report suspected sightings of sunflower broomrape by emailing pest@agr.wa.gov or calling 1-800-443-6684 (option 1). Include the reporting party’s name, location of the suspected weed, date encountered and photos.