Pest Profile: Narrow-Leaved Hawk’s Beard
Narrow-leaved hawk’s beard is a tough-to-control winter annual considered a noxious weed under the Saskatchewan Weed Control Act. A prolific seed producer, narrow-leaved hawk’s beard can produce up to 50,000 seeds per plant, which spread via the wind and are able to germinate and produce new plants soon after they’re shed.
Reduced-tillage farms are especially vulnerable to this weed pest, as airborne seeds can easily get caught in the stubble of an untilled field and grow there, rather than getting blown to the edges of a field. Because it’s a winter annual, the best time to scout is in the fall or during spring burn-off, but if you find it in your field, be careful to ensure that it really is narrow-leaved hawk’s beard, and not its nearly identical cousin, green-leaved hawk’s beard.
Reduced-tillage farms are especially vulnerable to this weed pest, as airborne seeds can easily get caught in the stubble of an untilled field and grow there, rather than getting blown to the edges of a field. Because it’s a winter annual, the best time to scout is in the fall or during spring burn-off, but if you find it in your field, be careful to ensure that it really is narrow-leaved hawk’s beard, and not its nearly identical cousin, green-leaved hawk’s beard.
TYPE
- Winter annual
- Broadleaf
IDENTIFICATION
The stems are erect, up to 3 feet tall, branched and leafy. Basal leaves are up to 6 inches long and 2 inches wide, with leaf margins varying from a few small teeth to deep lobes. Stem leaves are long and narrow and less than 1⁄2 inch wide. Flower heads are bright yellow.
CONTROL TIPS
- The plant is a prolific seed producer, capable of generating up to 50,000 seeds. Therefore, it’s important to focus on the prevention of seed production and the establishment of a competitive crop stand.
- Seed a competitive crop into a warm, moist seedbed as soon as possible.
- Depending on the life cycle (whether summer annual or winter annual), this weed can be controlled by fall- or spring-applied herbicides.
REGISTERED HERBICIDES
1 Control with additional 2,4-D
Please read each label to determine which herbicide is appropriate for the crop affected.
REFERENCES AND ADDITIONAL READING
Epp, Melanie. “Narrow-Leaved Hawk’s Beard Travelling.” Grainews. 17 April 2017. Online. https://bit.ly/2wdlIra