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Yellow Nutsedge


Description

Yellow nutsdege (Cyperus esculentus L.) is a warm-season, perennial weed common throughout Louisiana. It has leaves that resemble grass; however, it is a member of the sedge family. Yellow nutsdege does produce seeds, but they are rarely viable. Instead it spreads primarily through tubers produced from rhizomes (underground stems). It prefers areas with wet soil and is usually an indicator of poor drainage. Often confused with purple nutsedge, yellow nutsedge can be distinguished by its yellow seed head.

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Identification

Yellow nutsedge has narrow, shiny, grasslike leaves that are bright green in color. Leaves are usually sharply pointed at the tip. Stems are also bright green and are triangular in cross section. Yellow nutsedge produces yellow to light brown inflorescences (clusters of flowers) that extend from the base of the plant on tall stems. Yellow nutsedge produces small white to brown tubers, or nutlets, that grow from the tip of rhizomes (underground stems). For more information on yellow nutsedge identification and characterization, reference the USDA Plants Database.

Hint: Yellow nutsedge has light green leaves with pointed leaf tips and is generally taller in height compared to purple nutsedge, which has dark green leaves with rounded leaf tips and is generally shorter. Yellow nutsedge also produces single tubers at the tip of the rhizome.

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Narrow leaf tip

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Yellow inflorescence

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Nutlets and rhizomes


Cultural control practices

The best way to prevent or reduce weed encroachment is to maintain a healthy lawn through proper fertilization and soil pH and regular mowing. Properly maintaining a lawn through these cultural practices promotes dense and vigorous turfgrass, allowing it to better compete with weeds. Below are the recommended mowing heights and nitrogen fertility rates recommended per turfgrass species. Yellow nutsedge thrives in poorly drained or over-watered areas. In excessively wet areas, surface and subsurface drainage may be necessary. Irrigation may need to be reduced or eliminated in chronically wet areas.

Turfgrass Species Mowing Height Nitrogen Rate (per 1,000 ft2 per year)
Bermudagrass 1 to 2 inches Up to 3 pounds
Centipedegrass 1 to 2.5 inches Up to 2 pounds
St. Augustinegrass 2.5 to 3 inches Up to 3 pounds
Zoysiagrass 1 to 2.5 inches Up to 2 pounds

Chemical control practices

In addition to cultural practices, herbicide applications may be required to achieve effective weed control. There are several pre-emergence and post-emergence herbicide options available for yellow nutsedge control. Pre-emergence herbicides will suppress yellow nutsedge. However, post-emergence herbicides are more heavily relied upon, but multiple applications are often required throughout the growing season, especially during wet springs and summers.

When applying any type of herbicide, you must follow the manufacturer’s labeled directions. For more information regarding pesticides for turfgrass please reference the Louisiana Suggested Chemical Weed Control Guide.

St. Augustinegrass Centipedegrass Zoysiagrass Bermudagrass
Pre-emergence Herbicide Active Ingredients


metolachlor Yes Yes
Yes
Yes
dimethenamid-p Yes
Yes
Yes
Yes
dimethenamid + pendimethalin
Yes
Yes
Yes
Yes
Post-emergence Herbicide Active Ingredients
halosulfuron Yes
Yes
Yes
Yes
sulfosulfuron Yes
Yes
Yes
Yes
imazaquin Yes
Yes
Yes
Yes
sulfentrazone Yes
Yes
Yes
Yes
flazasulfuron Yes Yes Yes Yes
bentazon Yes Yes Yes Yes
metsulfuron + sulfentrazone Yes Yes Yes Yes
trifloxysulfuron No No Yes Yes
quinclorac + sulfentrazone No No Yes Yes
thiencarbazone + foramsulfuron + halosulfuron No No Yes Yes

For information regarding weed identification and control options please contact your local LSU AgCenter Extension Parish Office.


Download here: Louisiana Home Lawn Series: Yellow Nutsedge 3624-LL

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The LSU AgCenter and the LSU College of Agriculture

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