UC IPM: Information about Herbicides in Turfgrass

UC Pest Management Guidelines

Common name

Amount/Acre

Ag Use
R.E.I.+

NonAg Use
R.E.I.+

(trade name)

(hours)

When choosing an herbicide, consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.

PREPLANT

DAZOMET*

275 lb a.i./acre or 7.92 oz a.i./100 sq ft

—

(Basamid)

WSSA MODE OF ACTION GROUP NUMBER¹: 27

COMMENTS: Soil-applied, granular fumigant for control of annual weeds. Apply directly to the soil and mix 6 inches deep with a power tiller. Activity is better if irrigated after tilling in. Vaporproof tarping also improves weed control. Better on sandy soils than on clay soils. Seed in 3 weeks if temperature is over 60°F and soil is moist but not wet.

METAM SODIUM*

160–319.5 lb a.i./acre or 3.67–7.33 lb a.i. /1000 sq ft

—

(Vapam)

COMMENTS: Preirrigate soil to imbibe seeds and juvenate perennial propagules. Apply as soil begins to dry; soil temperature should be at least 50°F at 1 inch for best results. Apply in water on calm day; follow immediately with sprinkler irrigation to seal the soil surface or, preferably, cover with vaporproof covering. Seed in 2 weeks on light sandy soils, in 3–4 weeks on heavier clay or organic soils. Extend waiting period if temperature is below 60°F. Two applications are usually required to eradicate bermudagrass, nutsedge, or kikuyugrass. Rototilling before treatment will enhance control. Fumigants such as metam sodium are a prime source of volatile organic compounds (VOCs), which are a major air quality issue. Fumigate only as a last resort when other management strategies have not been successful or are not available.

GLYPHOSATE

2–4 lb a.i.

until dry

(Roundup, Roundup Pro)

WSSA MODE OF ACTION GROUP NUMBER¹: 9

COMMENTS: Glyphosate is a nonselective, foliar-applied postemergent herbicide that will eliminate nearly all established weeds and turf species from a site before seedbed preparation. It has no preemergence activity on emerging weeds or turf species. Use the lower rate for annual weeds and the higher rate for perennial weeds. Apply to actively growing weeds that are not stressed. Little mallow, burning nettle, and filarees are only partially controlled; marestail, and filaree have developed resistance to glyphosate.

POSTPLANT

Before weeds emerge

ATRAZINE*

1–2 lb a.i.

until dry

(Drexel Atrazine)

WSSA MODE OF ACTION GROUP NUMBER¹: 5

COMMENTS: Used for control of annual broadleaf weeds and some annual grasses in St. Augustine or zoysiagrass turf. Do not use on other turf types or injury will result. May be applied up to 30 days before cutting or lifting sod. Do not apply in light textured (sandy) soils where tree or shrub roots may absorb the herbicide.

BENSULIDE

7.5–10 lb a.i.

until dry

(Bensumec)

WSSA MODE OF ACTION GROUP NUMBER¹: 8

COMMENTS: Primarily used for preemergent control of annual grasses in most species of established turfgrasses (except bentgrass in CA). It can also be used in dichondra at seeding or any time thereafter. It is only available to certified applicators, but it can be applied to residential lawns as well as golf courses. Not for use in parks, recreational areas, or other public sites. Water in immediately after application with 0.5 to 1 inch of water. For annual bluegrass, crabgrass, or goosegrass control, apply 2 to 3 weeks before initial germination. If treating for both annual bluegrass and annual, warm season grass weeds, then up to 3 properly timed applications may be needed per year. Rates of application are dependent upon the number of applications made per year. The maximum label rate is 18 fl oz/1000 sq ft/year in two or more applications, depending on the weed species and the degree of infestation.

DCPA

10 lb a.i.

—

(Dacthal)

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: Apply to many species of established turfgrass before annual weeds germinate. For crabgrass control apply in late winter 2 to 3 weeks before initial crabgrass germination. Exact timing varies by location in California (Jan. for southern California, early to mid-Feb. for Central Valley and Central Coast area, and mid-Feb. to March 1 for northern California). Will not control crabgrass after germination. For annual bluegrass control, apply at the end of Aug. or early Sept. Also controls several broadleaf weeds. Incorporate with 0.1-0.2 inches water within 4 hours after application. Check label; currently Dacthal flowable is not registered for use on residential turf, whereas the 75% wettable powder formulation is. Do not use on bentgrass or dichondra.

DITHIOPYR

0.25–0.5 lb a.i.

until dry

(Dimension)

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: Apply to many species of established turf 2 to 3 weeks before annual weeds germinate. Apply in late winter to early spring for crabgrass, spurge, and oxalis, or in fall for annual bluegrass. May be applied as a single application in spring or fall, or as a split application with half being applied in spring and half in fall. Do not apply more than 1.5 lb a.i./year. Has postemergent activity on crabgrass seedlings up to the 3-leaf stage. Do not apply within 3 months of seeding, overseeding, or sprigging. May injure fine fescue or bentgrass in golf course greens if treated during periods of severe stress. Consult label for other turf restrictions.

ETHOFUMESATE

Label rates

until dry

(Prograss, Poa Constrictor)

WSSA MODE OF ACTION GROUP NUMBER¹: 8

COMMENTS: A translocated, selective herbicide that controls several annual grass and broadleaf weeds. Primary use is annual bluegrass management. Has both preemergent and early (two-leaf stage) postemergent activity and is most effective in programs that use both timings. May be used on home lawns, golf courses (not putting greens) and is safe for most turfgrasses (except zoysiagrass and fine fescue) but must be applied by a licensed applicator. See label for cultivar tolerances of turf species.

ISOXABEN

0.5–0.9975 lb a.i.

until dry

(Gallery 75 DF)

WSSA MODE OF ACTION GROUP NUMBER¹: 21

COMMENTS: Apply to many species of established turf in late summer or early fall before winter annual weeds germinate. Provides 6 to 8 months of control of many broadleaf weeds including: henbit, speedwells, oxalis, brassbuttons, and knotweed. A spring application helps control spurge and other summer broadleaf annuals. Follow application with at least 0.5 inch water. Will not control established weed plants. Not for use on putting greens or grass grown for seed.

NAPROPAMIDE

2–3 lb a.i.

—

(Devrinol) 50DF

WSSA MODE OF ACTION GROUP NUMBER¹: 15

COMMENTS: Apply at seeding or on established dichondra; can also be used on bermudagrass, St. Augustinegrass, and tall fescue. Principally for control of weedy grasses but will control some broadleaf weeds. A split application of 2 lb a.i. can be applied for crabgrass and 2 lb a.i. for goosegrass; apply 8 to 10 weeks apart. Apply in early fall for annual bluegrass contol. Follow applications with a minimum of 0.5 inch of water to wash material from the leaves and into the soil. Do not reseed or overseed within six months after application.

ORYZALIN

1.5–2 lb a.i.

see comments

until dry

(Surflan, Weed Impede)

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: For use on warm season grasses and tall fescue. Although labeled for use in tall fescue, oryzalin should not be applied to tall fescue under stress or roots will be inhibited. For this reason other preemergent herbicides are recommended. Apply on established turf 2 to 3 weeks before annual weeds germinate. Use low rate of application for annual bluegrass control in late summer or early fall. Use high rate in late winter or early spring before germination of summer annual weeds. Do not aerate or verticut after application. Do not use on bluegrass, bentgrass, or ryegrass turf. Long residual from a summer application may prohibit fall overseeding of a cool season grass in Bermuda turf. REI for Surflan is 24 hours. Weed Impede is until dry.

ORYZALIN/BENEFIN

2–3 lb a.i.

until dust settles

(XL 2G)

WSSA MODE OF ACTION GROUP NUMBERS¹: 3/3

COMMENTS: A granular formulation that combines two preemergent herbicides for increased weed activity in warm season grasses and tall fescue. Apply on established turf before annual weeds germinate. Do not aerate or verticut after application. Do not use on bluegrass, bentgrass, or ryegrass.

OXADIAZON

2–4 lb a.i.

until dry

(Ronstar G, 50 WSP, or Flo)

WSSA MODE OF ACTION GROUP NUMBER¹: 14

COMMENTS: The granule formulation can be used safely on most grass species, but bentgrass has some restrictions. Some foliar injury may be observed if the granules are applied to wet foliage or the herbicide is not washed from the leaves after application. Apply these formulations at least 2 weeks before turf greens in spring. Is only fairly effective for control of prostrate spurge or creeping woodsorrel (Oxalis) in California, but does control many other broadleaf and grass weeds. Ronstar's mode of action is different from most other preemergent herbicides that are root inhibitors. Ronstar is a shoot inhibitor, which is useful on newly sprigged bermudagrass, when spread by creeping stems and root formation is desirable. Ronstar may be used in fairways, parks, golf courses, and non-residential lawns. Do not use on newly seeded dichondra or golf course greens. It is only available to licensed applicators.

PENDIMETHALIN

Label rates

until dry

(Pre-M 3.3 EC, Pendulum, Pendulum AquaCap)

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: Apply to many species of established turf 2 to 3 weeks before annual weeds germinate. Useful in the control of many broadleaf and grass weeds including: crabgrass, foxtail, creeping woodsorrel (oxalis), and spurge. Use lower rate for control of annual bluegrass in fall or as a split application for control of crabgrass or spurge in late winter and early summer. Do not aerate or verticut after application. Do not overseed with grasses for 8–12 weeks after application. Do not apply on bentgrass.

PRODIAMINE

0.65–1. 495 lb a.i.

until dry

(Barricade)

WSSA MODE OF ACTION GROUP NUMBER¹: Unknown.

COMMENTS: Apply to many species of established turf 2 to 3 weeks before weeds germinate to control annual grasses and many broadleaf weeds, including creeping woodsorrel (oxalis) and spurge. It is very insoluble in water and lasts for a long time, giving good control. It will interfere with overseeding of grasses for 4 to 10 months, depending on the rate used. Turfgrass must be well established before use or roots will be inhibited. May thin turfgrass under stressed conditions, heavy wet soils, or shaded areas where growth is slow. Not for use on putting greens.

PRONAMIDE*

0.5–1.495 lb a.i.

until dry

(Kerb) 50WSP

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: Used for preemergent or early postemergent control of annual bluegrass in bermudagrass turf; the higher rate gives longer residual control. Do not use on seedling, newly sprigged, or newly sodded turf. Most effective in late fall at, or just before emergence. For postemergent control it takes 14 to 21 days before results are evident. Do not overseed with annual ryegrass within 90 days of treating with pronamide. Controls annual bluegrass slowly by inhibiting root development and thus reducing the weed vigor. Best control is accomplished when annual bluegrass is young and before seed head stage. Do not treat where the herbicide can move into sensitive cool season grass species, do not apply to a bermudagrass turfgrass that has been overseeded with a cool season grass, and do not overseed with cool season species for 90 days following treatment. Also used during spring to selectively remove overseeded rye from warm season grasses at 50% greenup. Not registered for use on residential lawns and only available to licensed applicators.

SIDURON

2-6 lb a.i.

until dry

(Tupersan)

WSSA MODE OF ACTION GROUP NUMBER¹: 7

COMMENTS: A preemergent herbicide that can be applied at planting, on newly planted or established cool season turfgrass (fescue, bluegrass or ryegrass) to control seedlings of warm season weeds, particularly crabgrass, bermudagrass, or kikuyugrass. Most cultivars of creeping bentgrass have shown tolerance to siduron. Can be used in golf courses (fairways, greens, aprons, and tees), ornamental lawns, parks, and sport facilities. Primarily used for turf renovation where bermudagrass or kikuyugrass are killed with glyphosate and a cool season grass is planted. Also used to remove perennial ryegrass from warm season grasses, usually bermudagrass, during spring transition. Only available to licensed applicators but can be used on residential lawns.

POSTPLANT

Before or after weeds emerge

There are a few herbicides for use in turfgrass that have both pre- and postemergent weed control activity. They are dithiopyr, ethofumesate, and pronamide. Their descriptions are listed under both categories. Many of these products may be used in tank mixes. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i.

POSTPLANT

After weeds emerge

BENTAZON

1 lb a.i.

until dry

(Basagran) T/O

WSSA MODE OF ACTION GROUP NUMBER¹: 6

COMMENTS: Apply in 40 gal water/acre for yellow nutsedge in established turfgrass; thorough coverage is important. The nutsedge should be growing vigorously with good soil moisture. If control is not as desired, apply a second treatment after 10–14 days. Do not apply more than 2 lb a.i./season. For optimum control, do not mow 3–5 days before or after application. Do not use on newly seeded or sprigged turf or golf course greens. May be mixed with 2,4-D.

BISPYRIBAC-SODIUM

Label rates

until dry

(Velocity SG)

WSSA MODE OF ACTION GROUP NUMBER¹: 2

COMMENTS: A selective postemergent herbicide for control of annual bluegrass, roughstalk bluegrass, and certain broadleaf weeds in golf courses and sod farms. Used in creeping bentgrass and perennial ryegrass (permanent, not overseeded), fairways, and tees. Do not use on greens or roughs.

BROMOXYNIL

0.25–0.5 lb a.i.

see label

until dry

(Buctril, etc.)

WSSA MODE OF ACTION GROUP NUMBER¹: 6

COMMENTS: Apply on young turfgrass after grass has emerged and when broadleaf weeds are in the 3- to 4-leaf stage or up to 6-inch weed height, or on rosette plants before they exceed 1.5 inches in diameter to control broadleaf weeds. On established turf, use lower rate on small weeds and higher rate on large weeds. During periods of high temperature, leaf tip burn may occur on turf. Do not use on bentgrass greens. Apply in at least 20 gal water/acre. May be tank-mixed with other broadleaf materials such as 2,4-D and 2,4-DP, MCPP, dicamba, MSMA, or DSMA, or combinations of these materials, depending upon the weed species present.

CARFENTRAZONE

0.0311 lb a.i.

—

until dry

(Quicksilver T & O)

WSSA MODE OF ACTION GROUP NUMBER¹: 14

COMMENTS: Controls a broad spectrum of annual and perennial broadleaf weeds in established turfgrass. May cause temporary yellowing of hybrid bermudagrass or tall fescue if under stress. Fast acting. A contact broadleaf herbicide that causes a quick burndown of weeds when temperatures are moderately warm. Control is still achieved in cold weather but takes longer. Does not control chickweed. Can be used in cool and warm season turfgrasses. It is also labeled for moss control. Often sold as a prepackaged mix (PowerZone, Speedzone) with other systemic broadleaf weed killers such as 2,4-D, MCPA, MCPP, or dicamba to control a broader spectrum of broadleaf weeds.

CARFENTRAZAONE/MCPA/MCPP/DICAMBA*

until dry

(Power Zone)

WSSA MODE OF ACTION GROUP NUMBERS¹: 14/4/4/4

COMMENTS: Fast acting. A combination of 4 herbicides for control of a broader spectrum of annual and perennial broadleaf weeds in established turfgrass. May cause temporary yellowing of hybrid bermudagrass or tall fescue, especially if they are under stress.

CLOPYRALID

Label rates

until dry

(Lontrel)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A translocated broadleaf herbicide that controls weeds in the bean/pea family (e.g., clovers), nightshades, and the sunflower family (includes dandelion, most composites, and thistles). Particularly effective on hard to control thistles, such as yellow star thistle. Combined and packaged with triclopyr (Confront) for control of additional broadleaf weeds. Use is restricted to golf courses only where clippings will not be used in off-site composting. Used in cool and warm season grasses; apply to healthy well-established turf with well-anchored root system. Susceptible to leaching through soil, so avoid potential groundwater contamination in sensitive sites. Also packaged and sold as a mix (Millenium Ultra Plus) with other postemergent, systemic broadleaf herbicides (2,4-D, dicamba, and MSMA).

DICAMBA*

0.25–0.5 lb a.i./100 gal water

until dry

(Banvel, etc.)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A foliar-applied, translocated broadleaf herbicide that has soil activity. Apply in 40 gal water/acre for control of chickweeds, clovers, prostrate knotweed, pearlwort, red sorrel, curly dock, and suppression of English daisy. Do not apply more than two times/year. The 4 lb acid equivalent/gal formulation can also be used for spot spraying; do not exceed 0.5 lb acid equivalent/acre/season. Active through the soil; do not use where roots of ornamental plants may extend into treated area or spray on tree basins. Spray on calm days to avoid spray drift onto susceptible crops or ornamentals. Do not use on dichondra.

DITHIOPYR

0.25–0.5 lb a.i.

until dry

(Dimension)

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: A preemergent herbicide with some postemergent activity. Apply to crabgrass before tillering stage. May be used with MSMA to control existing crabgrass. Equally effective on smooth or large crabgrass.

ETHOFUMESATE

Label rates

until dry

(Prograss, Poa Constrictor)

WSSA MODE OF ACTION GROUP NUMBER¹: 8

FLUAZIFOP

Label rates

see comments

until dry

(Fusilade II, Ornamec)

WSSA MODE OF ACTION GROUP NUMBER¹: 1

COMMENTS: A translocated, selective herbicide that controls most annual and perennial grasses. Used primarily to control grassy weeds in broadleaf ground covers, including dichondra. Will not control annual bluegrass. Apply when the grass is young and vigorous and has good soil moisture. Retreatments may be required for hard-to-kill weeds such as bermudagrass, dallisgrass, and kikuyugrass. Will not control nutsedge. Will injure most turfgrass species and is used primarily to suppress bermudagrass in tall fescue. A non-ionic surfactant must always be added to the spray tank. Restricted entry interval for agricultural use for Fusilade is 12 hours; for Ornamec it is 4 hours.

FLUROXYPYR

Label rates

until dry

(Spotlight)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: Controls clovers and medics and a few other broadleaf weeds in most established warm and cool season turf species (see label for turf species list). Fast acting translocated herbicide that may injure bermudagrass at higher rates. Do not use near tree or shrub roots, suckers, or shallow rooted plants to avoid injury. Do not use on golf course putting greens or tees. Use 2,4-D ester for tank mix, not compatible with 2,4-D amine formulation.

FORAMSULFURON

Label rates

until dry

(Revolver)

WSSA MODE OF ACTION GROUP NUMBER¹: 2

Selectively removes cool season grasses (annual bluegrass, perennial ryegrass, tall fescue, etc.) growing in established bermudagrass and zoysiagrass. It also suppresses dallisgrass. For use by licensed applicators only.

GLYPHOSATE

Label rates

see label

until dry

(RoundUp, KleenUp, various)

WSSA MODE OF ACTION GROUP NUMBER¹: 9

COMMENTS: A nonselective, translocated herbicide. Will injure all turfgrass species. Used primarily to control weeds before planting or in turfgrass renovation. Apply to rapidly growing weeds in 20 to 40 gal water/acre or as a spot treatment. For control of annual weeds shorter than 6 inches, apply 1 lb a.i./acre; if 6 inches or taller, apply 1.5 lb a.i./acre. Allow minimum of 3 days between application and renovation or cultivation. For control of perennial weeds, apply 4–5 lb a.i./acre to vigorous but nearly mature weeds (bermudagrass in summer-fall; field bindweed, at full bloom). In mowed turfgrass areas, do not mow before application. Delay verticutting, removing sod, or tillage for at least 7 days after treatment. To maximize control, allow the soil surface and root area to dry after verticutting or sod removal before replanting. When turfgrass or ornamentals are to be planted, a follow-up preemergent program is required to control the weed seeds.

HALOSULFURON

0.03–0.06 lb a.i.

until dry

(Sedgehammer, etc.)

WSSA MODE OF ACTION GROUP NUMBER¹: 2

COMMENTS: Apply to established turfgrass in summer for control of yellow and purple nutsedge, and green kyllinga suppression. For optimum control, do not mow 3 to 5 days before or after application. Usually requires two applications starting when sedge is in the 3- to 6-leaf stage followed 6–10 weeks later with the second application. Do not use more than 2 applications/season. This herbicide reacts slowly in the plant so do not expect immediate results. Use 0.25% nonionic surfactant for broadcast applications in equivalent to 100 gal water/acre (2 tsp/gal). Safe for use in cool and warm season turfgrass.

MCPA*

Label rates

until dry

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A translocated, broadleaf herbicide. When used at the same rate as 2,4-D is less effective in the control of most weed species but somewhat safer for the turfgrass. Often mixed, or only available in prepackaged mixes, with active ingredients such as mecoprop, dicamba, carfentrazone, or triclopyr to increase its effectiveness.

MCPA/TRICLOPYR/DICAMBA*

(Cool Power)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A combination of 3 translocated, broadleaf herbicides. Used on golf courses, parks, residential and institutional turf lawns. Effective on dandelions, chickweeds, plantains, oxalis, spurge, and many other broadleaf weeds. Safe in cool-season turfgrasses, except bentgrass greens and tees), bermudagrass and zoysiagrass. St. Augustine is moderately tolerant. Not for use in dichondra. Applied to foliage, but also soil active so avoid spraying shrub and tree roots in lawns.

MECOPROP

Label rates

(MCPP, Mecomec 2.5)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A translocated, broadleaf herbicide for control of chickweed, clover, prostrate knotweed, pearlwort, and other broadleaf weeds. Spray on calm days to avoid spray drift onto susceptible crops or ornamentals. Safer to use on bentgrass than 2,4-D; do not use on dichondra. Use 1 qt surfactant/100 gal spray. Frequently formulated into broadleaf herbicide mixes with 2,4-D and dicamba, but also MSMA, fluroxypyr, triclopyr, carfentrazone, or quinclorac.

MSMA

2–4 lb a.i.

until dry

(MSMA 6 Plus, etc.)

WSSA MODE OF ACTION GROUP NUMBER¹: 17

COMMENTS: A selective, translocated herbicide used principally for crabgrass, dallisgrass, nutsedge, and green kyllinga control. Also effective on a few broadleaf weeds. Use a surfactant to increase coverage and control. Apply when temperatures are warm (80 to 90°F), but do not apply when temperatures are hot (greater than 90°F) or turn injury could result. Temperature and turf type determine degree of selectivity. Make no more than two applications/season at a 30-day interval. Apply uniformly over area regardless of distribution of the weed. Hesitating with sprayer over weedier spots may cause excessive rate and injure or kill the turf. Use lower rates on more sensitive turfgrasses. Repeated applications of high rates reduces kikuyugrass. Turfgrass may be temporarily discolored. Bermudagrass, bluegrass, and zoysiagrass are most tolerant. Bentgrasses and fescues are moderately tolerant. Do not apply to St. Augustinegrass, red fescue, dichondra, or zoysiagrass. Apply in 175-200 gal water/acre.

PRONAMIDE*

0.75–1.5 lb a.i.

until dry

(Kerb) 50WSP

WSSA MODE OF ACTION GROUP NUMBER¹: 3

COMMENTS: A selective herbicide with pre- and early postemergent weed control on many grass weeds and chickweed. Used for control of annual bluegrass in bermudagrass turf only. Use 0.75–1 lb a.i. to control seedling to young tillering stages of annual bluegrass; a higher rate of 1–1.5 lb a.i. is needed for seed-forming stages. Do not apply where the herbicide can move into sensitive cool season grasses. Do not overseed cool season grasses within 90 days after treatment. It is also used to remove overseeded rye from warm season grasses at 50% greenup. For use by licensed applicators only.

QUINCLORAC

0.25–0.5 lb a.i.

until dry

(Drive)

WSSA MODE OF ACTION GROUP NUMBER¹: 26

COMMENTS: A selective, translocated herbicide for control of many broadleaf and grass weeds; primarily used for control of clover and crabgrass (although some biotypes of smooth crabgrass may be resistant). Also used in sequential applications with MSMA to limit kikuyugrass in warm season turf. Tips on mowing and adjuvants are specified on the label. Also formulated and packaged with other broadleaf weed herbicides.

QUINCLORAC/SULFENTRAZONE/2,4-D/DICAMBA

Label rates

until dry

(Q4 Turf Herbicide)

WSSA MODE OF ACTION GROUP NUMBERS¹: 26/14/4/4

COMMENTS: A combination of 4 active ingredients to make a versatile translocated, selective herbicide that will control many troublesome annual and perennial broadleaf and annual grassy weeds in established turfgrass. Controls clovers, composites, oxalis, plantains, spurge, thistles, wild carrot, garlic, and onion. Suppresses yellow nutsedge. Effective on crabgrass (although some biotypes of smooth crabgrass may be resistant). For use on residential and institutional lawns and in sod production. May cause temporary turfgrass yellowing. Adjuvants may result in additional injury. Temperatures above 90° F increase the chance of turf injury. Safe in cool season turf and fully dormant bermudagrass, zoysiagrass, and buffalograss. Not for use in bentgrasses, St. Augustinegrass, or dichondra. Not for use on greens, tees, or collars of golf courses. Not for use on lawns with desirable clovers or legumes.

SULFOSULFURON

Label rates

until dry

(Certainty)

WSSA MODE OF ACTION GROUP NUMBER¹: 2

COMMENTS: A preemergent and postemergent translocated herbicide. Controls many annual and perennial sedges, cool season grasses (Poa annua, Poa trivialis, tall fescue) and broadleaf weeds growing in established, warm season, perennial grasses including bermudagrass, St. Augustinegrass and zoysiagrass, centipede, and kikuyugrass. Can also be used to control Poa trivialis (roughstalk bluegrass) in creeping bentgrass. Used to remove tall fescue and sedges from warm season turfgrasses and Kentucky bluegrass.

TRICLOPYR

0.25–0.5 lb a.i.

until dry

(Turflon Ester)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A translocated herbicide used to control several broadleaf weeds; it is especially effective on creeping woodsorrel (oxalis) and clovers. Do not use on bentgrass or warm season turf species such as common and hybrid bermudagrasses and kikuyugrass. Sometimes used in tall fescue lawns to suppress bermudagrass. Has some soil activity, so do not apply high rates or make repeated applications over the root zones of shrubs and trees. Apply in 50–100 gal water/acre to vigorously growing broadleaf weeds, preferably in spring or fall. May be retreated 4 weeks following the first application for hard-to-kill weeds. To broaden weed spectrum and control dandelion, use a tank mix of amine or low volatile ester of 2,4-D with triclopyr. Do not apply mixture around trees or shrubs, because injury may result. Do not follow application with an irrigation within 4 hrs.

TRICLOPYR/CLOPYRALID

Label rates

—

until dry

(Confront)

WSSA MODE OF ACTION GROUP NUMBERS¹: 4/4

COMMENTS: A combination of two herbicides for control of a broad spectrum of annual and perennial broadleaf weeds in established cool and warm season turfgrass with well-anchored root systems. Usage restricted to golf courses only. Weeds in the legume family are very sensitive to low label rates, whereas weeds in the sunflower family will require the higher label rates. May injure stoloniferous grasses (bermudagrass and zoysiagrass) especially if the grass is stressed. Do not use on St. Augustinegrass or bentgrass. Do not reapply within 4 weeks and withhold irrigation for at least 6 hours after application. Clopyralid is susceptible to leaching through soil, so avoid potential groundwater contamination in sensitive sites.

TRIFLOXYSULFURON

Label rates

until dry

(Monument)

WSSA MODE OF ACTION GROUP NUMBER¹: 2

COMMENTS: A selective, translocated herbicide used to control annual sedges, yellow and purple nutsedge, green kyllinga, oxalis, and spurge. Also suppresses crabgrass and dallisgrass. Harmful to cool season turfgrass species; used to remove tall fescue, annual and perennial rye, and annual bluegrass (Poa annua) and roughstalk bluegrass (Poa trivialis) from bermudagrass, St. Augustinegrass, and zoysiagrass. It can only be used on golf courses, sod farms, and other non-residential turf, such as cemeteries and commercial building sites.

2,4-D LOW-VOLATILE ESTERS*

0.48–0.95 lb a.i.

until dry

(Weedone LV4)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A selective herbicide used for annual and perennial broadleaf weed control. Applied in spring when weeds are rapidly growing. Additional treatments may be required for late emerging weeds or on perennials. Available as an amine or ester formulation. The 2,4-D ester form is used for hard-to-kill perennial broadleaf weeds. Do not use it on newly-seeded turf, St. Augustinegrass, bentgrasses or dichondra. 2,4-D is often mixed with several other broadleaf weed killers (MCPP, MCPA, dicamba, clopyralid, carfentrazone, MSMA, triclopyr, quinclorac, etc.) to increase the spectrum of susceptible weeds or provide safety to turfgrass species or sites, or both. Apply in 100 gal water/acre. Use to control common yarrow, speedwells, mallows, mature knotweed. For spot treatments, use 4 tsp formulation/1 gal water.

AA.

2,4-D WATER-SOLUBLE AMINES*

1–1.5 lb a.i.

until dry

(Weedar 64)

WSSA MODE OF ACTION GROUP NUMBER¹: 4

COMMENTS: A selective herbicide used for annual and perennial broadleaf weed control. Applied in spring when weeds are rapidly growing. Additional treatments may be required for late emerging weeds or on perennials. Available as an amine or ester formulation. The amine formulation is generally more selective on turfgrass and is less subject to drift problems to nontarget species. For control of dandelion, plantain, and young pigweed, use 1 lb acid equivalent plus 1 qt surfactant in 100 gal water/acre. For spot treatment, use 2 tsp formulation plus 2 tsp surfactant to 1 gal water. For control of young knotweed (2- to 4-leaf stage), field bindweed, prickly lettuce, and filaree, use 1.9 lb acid equivalent plus 1 qt surfactant in 100 gal water/acre. For spot treatment, use 4 tsp formulation plus 2 tsp surfactant to 1 gal water. On bentgrasses use water-soluble amine only and do not exceed 0.75 lb acid equivalent/acre.

BB.

2,4-D*/MCPP/DICAMBA*

Label rates

until dry

(Trimec, Triplet, etc.)

WSSA MODE OF ACTION GROUP NUMBERS¹: 4/4/4

COMMENTS: For broad-spectrum control of broadleaf weeds. Many formulations available for different turfgrass species. Use lower rates for bentgrass, hybrid bermudagrass and other sensitive turfgrasses. Nonselective on dichondra. Avoid applying to drought- and heat-stressed turf. Do not irrigate within 24 hrs of application. Newly seeded turf should not be treated until after the second or third mowing. Bentgrass is the most sensitive of the turfgrasses. Read label for further application directions. Do not allow spray drift to contact broadleaf ornamentals or injury may occur.

Permit required from county agricultural commissioner for purchase or use.

Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode of action numbers are useful in planning mixtures or rotations of herbicides with different modes of action. For more information, see http://www.hracglobal.com.

Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Agricultural use applies to sod farms and commercial seed production.

—

Indicates use is not listed on label.

UC IPM Pest Management Guidelines: Turfgrass
UC ANR Publication 3365-T
Weeds
C. A. Wilen, UC IPM Program, UC Cooperative Extension, San Diego County
M. LeStrange, UC Cooperative Extension, Tulare County
M. A. Harivandi, UC Cooperative Extension, Alameda County
Acknowledgment for contributions to Weeds:
C. L. Elmore, Vegetable Crops/Weed Science, UC Davis
D. W. Cudney, Botany and Plant Sciences, UC Riverside
V. A. Gibeault, Botany and Plant Sciences, UC Riverside

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/r785700511.html revised: September 23, 2009. Contact webmaster.

How to Manage Pests

UC Pest Management Guidelines

Turfgrass

Herbicide Treatment Table

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