Yellow nutsedge (Cyperus esculentus) —sometimes referred to as nutgrass—is a persistent weed problem in lawns, athletic fields, and golf course turf. It thrives in moist, poorly drained soils and can persist in full sun and moderate shade. An aggressive weed, it spreads via underground stems and tubers.
Many turf managers and homeowners find its yellow color, coarse texture, and fast growth rate objectionable in stands of cool-season turf, which also makes it relatively easy to identify. Stem bases typically show a reddish hue when outer leaf sheaths are stripped away. It also has yellow nutsedge has angular, three-sided stems, which can be detected by holding and turning the stem base between thumb and index finger.
Fortunately, yellow nutsedge can be controlled using good cultural practices and proper herbicides applied at the correct stage of growth, which usually occurs late spring or early summer. (This month is ideal). A perennial, new plants are primarily produced from nodes on rhizomes and from tubers, which can overwinter. Tubers typically begin to form at the tips of rhizomes in late June or early July. A single plant can produce multiple tubers which can remain dormant in soil from one to several years before germinating. Leaves and stems emerge in spring and grow rapidly during warm weather in summer when leaf growth of cool-season turfgrasses slows. The foliage of yellow nutsedge dies back in the fall following the first hard frost.
Yellow nutsedge is typically introduced through soil contaminated with tubers and rhizomes. Although there are no practical means of detecting reproductive structures in soil, using soils from sites with no history of infestation can lessen the chances of contamination.
If only a few yellow nutsedge plants are infesting a lawn, they can be removed by hand pulling soon after leaf emergence in spring and before tubers form later in the growing season. Be sure to remove as much of the below-ground portion of the plants as possible, since broken bits of rhizomes can give rise to new plants. Improving turf density through fertilization, regular mowing, and use of turfgrasses well-adapted to site conditions will help to slow the spread of yellow nutsedge, but may not provide effective suppression once it becomes established.
The most effective control of yellow nutsedge with herbicides is obtained when foliage is visible in the turf canopy, and before tubers begin to mature in mid to late summer. It’s important to treat nutsedge before tubers mature because these underground structures can give rise to many new plants in subsequent years. Herbicides are typically most effective in controlling nutsedge when mowing is curtailed at least two to three days before and after application.
Herbicides labeled for control or suppression of yellow nutsedge in cool-season turf include bentazon (Basagran T&O); sulfentrazone and sulfentrazone-containing products (Dismiss, Surepyc, Dismiss NXT, Solitare, Solitare WSL, Echelon 4SC, Q4 Plus, Foundation, Momentum 4-Score, SureZone, Surge, and TZone SE); halosulfuron-methyl (Sedgehammer, Prosedge, and Sedgemaster); imazosulfuron (Celero); mesotrione (Tenacity); and dimethenamid-P (Tower). A new nutsedge herbicide, pyrimisulfan (Vexis)*, was not too long ago launched.
Basagran T&O is a selective contact herbicide that incorporates bentazon, a photosynthesis inhibitor in prone weeds, because the energetic ingredient. This herbicide is comparatively fast-acting, with harm signs showing on nutsedge inside 5 to seven days of remedy. Basagran T&O can be utilized on established Kentucky bluegrass, fescues, ryegrass, and bentgrass for management of yellow nutsedge and a few broadleaf weeds. Management might be improved with the addition of a methylated seed oil or crop oil focus. A second utility might be made seven to 10 days after the primary utility if wanted, however at least 21 days after the primary utility on perennial ryegrass. Trials at Penn State point out that Basagran T&O is efficient for yellow nutsedge management utilizing a single utility of 0.75 fl ouncesproduct per 1000 sq ft. Foliar harm has been noticed with this product on perennial ryegrass in warmth and drought stress conditions.
Sulfentrazone and sulfentrazone-containing merchandise
Dismiss and Surepyc are contact herbicides labeled for management of yellow nutsedge and comprise 39.6% sulfentrazone because the energetic ingredient. In distinction to most systemic herbicides, Dismiss and Surepyc are very fast-acting. A latest trial at Penn State demonstrated pronounced harm signs on yellow nutsedge two days following an early July utility, and handled crops had been now not seen within the stand 10 days after utility. Each merchandise may cause foliar harm to some cultivars of tremendous fescues and neither product is labeled to be used on placing greens.
Dismiss NXT incorporates sulfentrazone and a small quantity of carfentrazone-ethyl (3.53%) and is labeled for management or suppression of yellow nutsedge and a few broadleaf weeds. Solitare and Solitare WSL (sulfentrazone and quinclorac) are additionally labeled for management or suppression of yellow nutsedge and broadleaf weeds in most cool-season turfgrasses. Echelon 4SC (sulfentrazone and prodiamine) is labeled for postemergence management or suppression of yellow nutsedge in turf, in addition to preemergence management in non-cropland, naked floor areas. Customers ought to concentrate on prolonged seeding restriction intervals after utilizing Echelon 4SC because of the preemergence herbicide exercise of prodiamine. Another sulfentrazone-containing merchandise, akin to Basis, Momentum 4-Rating, SureZone, Surge, and TZone SE, have small concentrations of sulfentrazone and are solely labeled for suppression of yellow nutsedge.
Sedgehammer, Prosedge, and Sedgemaster are herbicide merchandise that comprise the energetic ingredient halosulfuron-methyl, a sulfonylurea herbicide with systemic exercise. These merchandise are labeled to be used on most cool-season turfgrasses. Labels recommend including a non-ionic surfactant at 0.25% v/v to the spray resolution for optimum management of yellow nutsedge. If wanted, one other utility might be made six to eight weeks after the preliminary utility. Sedgehammer+ is a particular formulation that’s premixed with a surfactant.
Sedgehammer, Prosedge, and Sedgemaster are handiest when utilized to nutsedge on the three to eight-leaf stage. Though very efficient, halosulfuron-methyl-containing merchandise act slowly. In a trial performed at Penn State, harm signs following a Sedgehammer remedy didn’t turn into seen till a couple of week after utility, with full desiccation occurring three weeks later. Though slow-acting, the energetic ingredient will ultimately translocate to the rhizomes and tubers and kill your entire plant. For finest outcomes, don’t mow two to a few days earlier than or after utility.
Celero herbicide incorporates the energetic ingredient imazosulfuron, which is a member of the sulfonylurea herbicide class and has systemic exercise in prone crops. This product is labeled to be used on most cool-season turfgrasses and controls a number of totally different sedge species and a few broadleaf weeds. A non-ionic surfactant at 0.25% v/v should be added to the spray resolution for optimum management. Purposes ought to start after nutsedge crops have reached the three-leaf stage of progress. For heavy yellow nutsedge infestations, a second utility might be made 21 days after the primary remedy.
Tenacity is a well-liked herbicide that controls cussed grassy weeds akin to bentgrass, nimblewill, crabgrass, and yellow nutsedge with the energetic ingredient mesotrione. Tenacity has systemic exercise however is considerably slow-acting. Remedy results embody extremely seen white crops, which can be objectionable in some circumstances. Nonetheless, Tenacity has the benefit of being secure on newly seeded turf (besides tremendous fescues) and might present some preemergence and postemergence management of crabgrass. Therefore, this herbicide could also be a good selection if younger crabgrass is current with nutsedge.
Tenacity is labeled to be used on most cool-season grasses, however as a result of it kills bentgrass, it should be used with warning on golf programs. A second utility two to a few weeks after the preliminary utility could also be required for full management and for optimum management, apply Tenacity with a non-ionic surfactant. Along with controlling yellow nutsedge and a few grass weeds, this herbicide can even management or suppress many broadleaf weeds.
A latest trial at Penn State confirmed glorious management of yellow nutsedge infesting new Kentucky bluegrass utilizing a single utility of Tenacity at 8.Zero fl ouncesper acre. Though the nutsedge and crabgrass within the handled space remained white for 3 to 4 weeks, the weeds had been killed, and a follow-up utility was not essential. No harm was noticed on the Kentucky bluegrass.
Tower is strictly a preemergence herbicide that’s labeled for management of sedges and sure annual broadleaf and grass weeds. The energetic ingredient of Tower is dimethenamid-P and is labeled just for use on golf programs for cool-season turfgrasses. Purposes ought to be made to actively rising established turf in spring when soil temperatures are 55°F or larger.
Dr. Landschoot is a professor of Turfgrass Science with Penn State. Tanner Delvalle and Tim Abbey are Extension educators with Penn State. For the unique article, go to here.
*Dr. Landschoot has not but labored with Vexis and so doesn’t embody it on this article. For extra info on Vexis, go to here.