Annual ryegrass (ARG) is not a true annual, but is generally not cold tolerant so it typically dies out in Wisconsin winters It has rapid growth with good biomass production when summer seeded on most soil types. It has a shallow, fibrous root system desirable for erosion control.
Though a somewhat popular and economical cover crop, planting ARG is discouraged due to concerns with its potential to become a difficult to control weed. It can overwinter in the Midwest with mild conditions. It can be a prolific seed producer in the seeding year and several glyphosate resistant biotypes have been identified. If it over-winters, it can be difficult to control with herbicides.
Avoid allowing ARG go to seed. If ARG over-winters, an intensive control protocol should be followed:
- Spray early, when ARG is 4”-6” tall and is actively growing with warm conditions.
- Use 1.25-1.75 lb acid equivalent/acre glyphosate (eg, 42 oz Roundup Powermax).
- Add 8-16 oz 2,4-D if broadleaves are present.
- Use the recommended AMS volume to lower pH of spray water (pH <5).
- 15-20 gpa spray volume with medium droplet nozzles for good penetration.
- Spray by 3 pm (> 4 hours sunlight remaining after spray application)
Seeding rate: 15-25 lbs per-acre alone
Seeding depth: ¼” to ½”
Management and termination
In a cover crop mix
After wheat: AGR be a good compliment for brassicas and/or annual clover.
Seeding rate in mixes: 8-15 lbs per-acre in a mix with brassicas or clovers
Research in Wisconsin
Termination of winter rye and annual ryegrass using glyphosate