Dallisgrass

Description

Dallisgrass, field paspalum, and thin paspalum are common perennial weeds in turf, and are some of the more difficult-to-control weeds. All three species resemble each other very closely, and field paspalum and thin paspalum are often mistakenly called dallisgrass. Thin paspalum has a glossier, more shiny leaf when young than dallisgrass. Dallisgrass leaf appearance is very similar to crabgrass, which is a dull green appearance.

Cultural Control

Dallisgrass, like other perennial paspalums, is one of the more difficult-to-control weeds in turfgrasses. Perennial grass weeds such as dallisgrass are not desirable as turfgrass species under any conditions. Therefore, every effort should be made to prevent these weedy grasses from becoming established in turf, as selective control measures are usually difficult. Maintaining a dense, healthy turf year round by proper mowing and fertilization helps prevent encroachment and weed establishment.

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
[thiencarbazone-methyl + foramsulfuron + halosulfuron], MOA 14 + 2 + 2 (60.5 WG) (Tribute Total) 0.0735 oz 3.2 oz 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.​
MSMA, MOA 17 (6 SL, 6.6 SL)(various brands) several concentrations 1.82 to 4.5
Precaution and Remarks: MSMA is only registered for golf course, sod farm, and highway right-of-way use. Bermudagrass, bluegrass and zoysiagrass are tolerant. Injury may result on bentgrass, fescue and also St. Augustinegrass grown for commercial sod production only. Do not use on carpetgrass or centipedegrass. MSMA restrictions: For existing golf courses, spot treat (100 square feet per spot) not to exceed 25% of total acreage. For new courses, make 1 broadcast application per year. For sod farms, make 1 to 2 broadcast applications per year and maintain 25 feet buffer around permanent water bodies. For highway rights of way, make 2 broadcast applications and maintain 100 feet buffer around permanent water bodies.
MSMA, MOA 17 (various brands) + metribuzin, MOA 5 (75 DF) (Sencor) several concentrations
+
0.17 to 0.33 lb
1.5 to 2
+
0.125 to 0.25
Precaution and Remarks: See remarks for MSMA and metribuzin. The combination improves goosegrass control. Should be applied to bermudagrass only.
topramezone, MOA 27 (2.8 L) (Pylex) 0.023 to 0.034 fl oz 1 to 1.5 fl oz 0.021875 to 0.0328125
Precaution and Remarks: Labeled for broadcast treatment use in residential and athletic field turf, as well as in nonresidential turf sites including sod farms, golf courses (excluding greens and collars), parks, roadsides, cemeteries, and commercial properties. Tolerant turf species include Kentucky bluegrass, tall and fine fescue, perennial ryegrass, and centipedegrass at seeding and then anytime beyond 28 days after seeding. Add crop oil concentrate or methylated seed oil for enhanced control at 0.5 to 1% by volume. Don’t apply greater than 2 fluid ounces per acre per application or 4 fluid ounces per acre per year. Bleaching intensity of susceptible weeds reduced and broadleaf weed spectrum increased if tankmixed with quinclorac, [quinclorac + mecoprop + dicamba] or triclopyr. For suppression of above-listed weeds, add triclopyr at 1 pound ai per acre and make either 2 or 3 applications at 3 to 4 week intervals depending on topramezone rate. Creeping bentgrass is marginally tolerant to topramezone at 0.25 fluid ounces per acre. Test on a small area before large-scale use. Sequential applications may be required to achieve desired level of weed control. For bermudagrass and sheashore paspalum use 0.5 to 0.75 ounces per acre plus MSO at 1.5 pints per acre. Apply only to established bermudagrass and seashore paspalum.​

Species Data

  • SEEDHEAD / FLOWER
    • raceme; hairy spikelets arranged in 4 rows on 3 - 8 alternate branches on tall (up to 5 feet in unmowed situations) terminal stalks
      ​Figure 1, Figure 2, Figure 3, Figure 4
  • VERNATION TYPE
  • LIGULE TYPE
  • GROWTH SEASON / LIFE CYCLE
    • perennial weed
  • AURICLE TYPE
  • LEAF BLADE TIP SHAPE
    • sharp-pointed; flat, sharply creased, not hairy or with a few hairs at base, hairs behind ligule, edges smooth or rough
      Figure 10
  • LEAF BLADE WIDTH
    • 0.28 - 0.6 inches (7 - 15 mm) wide
  • STOLON PRESENCE
    • absent
  • RHIZOME PRESENCE
    • present; occasional and very short
  • COLLAR TYPE
  • SHEATH MARGIN
    • split with overlapping margins
  • SHEATH TYPE
    • flattened; sheath is not densely hairy, often has long hairs near base of plant; slightly creased
Dallisgrass seedheadFigure 1. Dallisgrass seedhead.Dallisgrass seedheadFigure 2. Dallisgrass seedhead.Dallisgrass seedheadFigure 3. Dallisgrass seedhead.Dallisgrass seedheadFigure 4. Dallisgrass seedhead.Dallisgrass vernationFigure 5. Dallisgrass vernation.Dallisgrass liguleFigure 6. Dallisgrass ligule.Dallisgrass liguleFigure 7. Dallisgrass ligule.Dallisgrass auricleFigure 8. Dallisgrass auricle.Dallisgrass auricleFigure 9. Dallisgrass auricle.Dallisgrass leaf blade tip shape.Figure 10. Dallisgrass leaf blade tip shape.Dallisgrass collarFigure 12. Dallisgrass collar.Dallisgrass collarFigure 13. Dallisgrass collar.Dallisgrass collarFigure 14. Dallisgrass collar.Dallisgrass collarFigure 15. Dallisgrass collar.

Written By

Photo of Dr. Charles PeacockDr. Charles PeacockProfessor and Extension Turfgrass Specialist (919) 515-7615 charles_peacock@ncsu.eduCrop and Soil Sciences - NC State University
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This Extension factsheet can also be viewed at:
https://content.ces.ncsu.edu/Dallisgrass