Weeds ›

Perennial Ryegrass

Description

Perennial ryegrass is a bunch-type grass that is used for winter overseeding on sites where high quality and winter color are needed. The texture, color, and density of perennial ryegrass are very similar to those of Kentucky bluegrass. Perennial ryegrass is often utilized for winter overseeding on golf course fairways and teeboxes, athletic fields, and high profile home lawns. Perennial ryegrass is often confused with tall fescue and/or Kentucky bluegrass. However, Kentucky bluegrass has a boat-shaped leaf tip and distinctive light-colored lines on both sides of the midrib. Tall fescue has rough leaf blade margins whereas perennial ryegrass has smooth ones. Also, tall fescue has rolled vernation in the leaf bud and perennial ryegrass has folded vernation.

Cultural Control

Perennial ryegrass is often overseeded to provide winter color in warm climates where turf is utilized in winter months. When warm weather prevails in late spring or early summer, this species usually will not survive. However, in the transition zone, especially during cool summers, wet summers, or both, perennial ryegrass can survive the summer and often becomes clumpy. This very attractive turf species becomes a difficult-to-control weed in these conditions. Control strategies should concentrate on controlling perennial ryegrass before it becomes clumpy.

Chemical Control

Herbicide and Formulation
Amount of Formulation per 1,000 sq ft
Amount of Formulation per Acre
Pounds Active Ingredient per Acre

Postemergence Control

Herbicide and Formulation

flazasulfuron, MOA 2 (Katana) 25 DG

Amount of Formulation per 1,000 sq ft

0.011 to 0.069 oz

Amount of Formulation per Acre

0.5 to 3 oz

Pounds Active Ingredient per Acre

0.0078 to 0.0469

Precaution and Remarks

For use on well established bermudagrass, zoysiagrass, centipedegrass and seashore paspalum grown on nonresidential turf including golf courses, industrial parks, tank-sod- and seed farms, cemeteries, athletic field and commercial lawns. Apply a maximum of 1.5 ounces per acre on fully green centipedegrass and seashore paspalum. 3 ounces per acre needed for annual bluegrass control and best if applied in spring. 0.5 to 1.5 ounces per acre will control perennial and Italian ryegrass. For clumpy ryegrass, use 1.5 to 3 ounces per acre. 1.5 ounces per acre needed for tall fescue control. 2.25 to 3 ounces per acre needed for poa trivialis control. Include a nonionic surfactant at 0.25% by volume.

Postemergence Control

Herbicide and Formulation

foramsulfuron, MOA 2 (Revolver) 0.19 SC

Amount of Formulation per 1,000 sq ft

0.2 to 0.6 fl oz

Amount of Formulation per Acre

8.8 to 26.2 fl oz

Pounds Active Ingredient per Acre

0.013 to 0.039

Precaution and Remarks

For use on bermudagrass and zoysiagrass grown on home lawns, golf courses and sod farms. Do not use on warm season turfgrass collars surrounding bentgrass greens. May be applied up to 1 week prior to overseeding. Do not apply within 2 weeks of bermudagrass sprigging. Apply in 25 to 60 gal water per acre. Rainfast after 2 hours. Surfactant not required.

Postemergence Control

Herbicide and Formulation

rimsulfuron, MOA 2 (TranXit GTA) 25 DF (Rimsulfuron 25 DF) 25 DF

Amount of Formulation per 1,000 sq ft

0.011 to 0.092 oz

Amount of Formulation per Acre

0.5 to 4 oz

Pounds Active Ingredient per Acre

0.0078 to 0.0625

Precaution and Remarks

May be applied to bermudagrass, zoysiagrass and centipedegrass on professionally managed sports facilities at professional and collegiate levels, golf courses, sod farms, roadsides, industrial and commercial lawns. For annual bluegrass control, apply November through December and again February through March if needed at 2 ounces per acre. May be applied 10 to 14 days prior to overseeding. For overseeded removal, apply 2 ounces per acre 3 to 4 weeks before desired removal date, and repeat 3 weeks later if needed. For weed control along roadsides, apply 4 ounces per acre if single application only. A nonionic surfactant at 0.25% by volume or an oil adjuvant such as crop oil concentrate and modified seed oil at 1% by volume are required. Do not apply to cool-season turfgrasses, residential lawns or newly sprigged/sodded bermudagrass.

Postemergence Control

Herbicide and Formulation

metsulfuron + rimsulfuron, MOA 2 + 2 (Negate 37 WG) 37 WG

Amount of Formulation per 1,000 sq ft

0.0344352 oz

Amount of Formulation per Acre

1.5 oz

Pounds Active Ingredient per Acre

0.0346875

Precaution and Remarks

Use on well established bermudagrass and zoysiagrass grown on nonresidential turf including golf courses, sod farms, industrial and commercial lawns, and professionally managed college and professional sports fields. Overseeding can occur 2 months after application. Include a nonionic surfactant at 0.25% by volume.

Postemergence Control

Herbicide and Formulation

sulfosulfuron, MOA 2 (Certainty) 75 DG

Amount of Formulation per 1,000 sq ft

0.017 to 0.046 oz

Amount of Formulation per Acre

0.75 to 2 oz

Pounds Active Ingredient per Acre

0.035 to 0.09375

Precaution and Remarks

May be applied to certain ornamental native grasses and also bermudagrass species, zoysiagrass, centipedegrass, St. Augustinegrass, and kikuyugrass grown on sod farms, golf courses (excluding greens), commercial and residential turf that is highly managed, and other noncrop areas. Use 1.5 to 2 ounces per acre for fall annual bluegrass control 7 to 10 days before overseeding. Use 0.75 to 1.25 ounces per acre for fall or winter control in nonoverseeded bermudagrass, and reapply if needed but not before 21 days after initial application. For tall fescue control, two applications may be required at 4- to 10-wk intervals. Perennial ryegrass control not as complete as with Revolver, TranXit GTA, or Monument 75 WG. Use a nonionic surfactant at 0.25% by volume. Do not exceed 2.66 ounces per acre per year.

Postemergence Control

Herbicide and Formulation

trifloxysulfuron, MOA 2 (Monument 75 WG) 75 WG

Amount of Formulation per 1,000 sq ft

0.0023 to 0.0129 oz

Amount of Formulation per Acre

0.1 to 0.56 oz

Pounds Active Ingredient per Acre

0.0047 to 0.0263

Precaution and Remarks

May be applied to residential bermudagrass and zoysiagrass and also on golf courses, sod farms, and other nonresidential turf areas. A nonionic surfactant at 0.25 to 0.5% by volume is recommended. Temporary discoloration may occur if used with MSO or COC. May be applied 3 weeks prior to overseeding. Use rates of 0.1 to 0.3 ounces per acre to remove overseeded perennial ryegrass and Poa trivialis to aid bermudagrass spring transition. Labeled turf species can be seeded or sprigged into treated areas 4 weeks after application.

Postemergence Control

Herbicide and Formulation

metsulfuron, MOA 2 (Blade, Manor, or MSM Turf) 60 WDG

Amount of Formulation per 1,000 sq ft

0.003 to 0.02 oz

Amount of Formulation per Acre

0.125 to 1 oz

Pounds Active Ingredient per Acre

0.005 to 0.038

Precaution and Remarks

May be applied to established bermudagrass, zoysiagrass (Meyer or Emerald), St. Augustinegrass, Kentucky bluegrass or fine fescue. Do not apply to turf less than 1 year old. Do not exceed 0.5 ounces per acre on centipedegrass, fine fescue, or Kentucky bluegrass. See label for a complete list of weeds controlled. The addition of 0.25% nonionic surfactant will enhance control. May be used for removal of perennial ryegrass from overseeded warm-season turf species. For bahiagrass control, use 0.25 to 0.75 ounces per acre after spring greenup but before seedhead development. A repeat treatment may be necessary in 4 to 6 weeks.

Postemergence Control

Herbicide and Formulation

(Patriot) 60 WDG

Amount of Formulation per 1,000 sq ft

0.007 to 0.046 oz

Amount of Formulation per Acre

0.33 to 2 oz

Pounds Active Ingredient per Acre

0.012 to 0.075

Precaution and Remarks

Apply to unimproved industrial turf only. Use maximum of 0.5 ounces per acre for fescue and bluegrass and 2 ounces per acre for bermudagrass.

Postemergence Control

Herbicide and Formulation

metsulfuron + rimsulfuron, MOA 2 + 2 (Negate 37 WG) 37 WG

Amount of Formulation per 1,000 sq ft

0.0344352 oz

Amount of Formulation per Acre

1.5 oz

Pounds Active Ingredient per Acre

0.0346875

Precaution and Remarks

See comments under postemergence annual bluegrass control. For bahiagrass control, a repeat treatment may be necessary 4 to 6 weeks after initial application.

Postemergence Control or Suppression of Summer Weeds Such as Crabgrass Species

Herbicide and Formulation

thiencarbazone + foramsulfuron + halosulfuron, MOA 14 + 2 + 2 (Tribute Total) 60.5 WG

Amount of Formulation per 1,000 sq ft

0.0735 oz

Amount of Formulation per Acre

3.2 oz

Pounds Active Ingredient per Acre

0.121

Precaution and Remarks

Apply to well-established residential and commercial bermudagrass and zoysiagrass (Emerald, Meyer, Zeon) lawns, golf courses (excluding greens), athletic fields, sod farms, roadsides, parks, cemeteries and recreational areas. Do not exceed 3.2 ounces per acre per application or 6.4 ounces per acre yearly. Use 0.25 to 0.5% by volume nonionic surfactant or 0.5 to 1% by volume methylated seed oil. After application, wait 12 weeks to overseed ryegrass or bermudagrass. Wait 1 month after bermudagrass seedling emergence and 2 weeks after sprigging or sodding bermudagrass before treating. Temporary stunting and yellowing may last up to 2 weeks but turf will recover. Crabgrass and goosegrass are controlled up to 2 tiller stage.

Presentations

Publications

Species Data

Seedhead/Flower

a spike, with flattened spikelets along each stem

Vernation type

leaves folded in the bud

vernation
vernation
vernation
vernation2
vernation2
vernation2
Ligule Type

membranous; collar-like to blunt, may be toothed near top, 0.02 - 0.06 inches (0.5 - 1.5 mm) long

dscn0952
dscn0952
dscn0952
dscn0953
dscn0953
dscn0953
dscn0964
dscn0964
dscn0964
Growth Season/Life Cycle

cool season turf or perennial weed

Auricle type

rudimentary

auricles
auricles
auricles
dscn0958
dscn0958
dscn0958
dscn0964
dscn0964
dscn0964
Leaf blade tip shape

sharp-pointed; bright green, sharply creased, deeply ridged upper surface, lower surface smooth and glossy, edges slightly rough

dscn0949
dscn0949
dscn0949
Leaf blade width

0.08 - 0.2 inches (2 - 5 mm) wide

Stolon Presence

absent

Rhizome Presence

absent

Collar Type

divided by midrib, not hairy, distinct

Sheath Type

sheath is usually flattened, reddish at base

vernation2
vernation2
vernation2