Sunflower broomrape
Orobanche cumana
Washington State Classification
Class A — Eradication Required Statewide
Sunflower broomrape can reduce sunflower and tomato yield by 80% to 100%.
Quick Reference
Identification
Growth Habit
Sunflower broomrape is only visible above the soil when it is going to flower soon, is flowering, or is seeding. This process can take only a couple weeks in June and July.
Leaves
As an obligate parasite, which does not photosynthesize, it does not have true leaves. There are small, triangular bracts that appear on the stem and near the flowers, but are not leaves.
Flowers
Flowers are curving trumpet-shaped tubes. They are fuzzy and can be purple, white, tan, or brown, generally with a yellowish center when fully open.
Fruit & Seeds
The seeds are produced prolifically, are dust sized, can easily spread on the wind, and can remain viable in the soil for at least 50 years, but likely longer.
Impact
Sunflower broomrape can reduce sunflower and tomato yield by 80% to 100%. It also heavily impacts tobacco, potatoes, peppers, sage, and potentially our native sunflowers.
Ecology & Spread
Habitat
Agriculture lands, flower fields, sagebrush steppe, pasture, grasslands, open areas, and among sunflower, tomato, tobacco, potato, and pepper crops.
Spread Mechanisms
Reproduction
Seed only.
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