General Information


QuickSilver Herbicide is a contact herbicide with little or no residual activity that provides selective postemergence control of broadleaf weeds and silvery-thread moss (Bryum argenteum) in turfgrass. The active ingredient of QuickSilver Herbicide is carfentrazone-ethyl. It is an aryl triazolinone herbicide, which interrupts chlorophyll synthesis and produces metabolic byproducts that disrupt plant cell membranes. This process only occurs in susceptible green plants in the presence of light.

QuickSilver Herbicide rapidly penetrates into the plant cells and symptoms may be apparent on foliage of susceptible weeds in 24 hours or less. Complete desiccation and death occurs within 7 to 14 days of application. QuickSilver Herbicide is rainfast within one hour after application.

This product is most effective when applied to actively-growing winter and summer annual seedlings. It also increases the speed of kill and expands the spectrum of control of mature and perennial broadleaf weeds (See \"Weeds Controlled\" section) when applied in a tank mixture with other postemergence herbicides.

Extremes in environmental conditions e.g. excessively high or low moisture or temperature may affect the activity of this product. Under warm, moist conditions appearance of herbicide symptoms may be accelerated while under very dry or cool conditions the expression of herbicidal symptoms is delayed. However, this product remains highly effective under both cool and warm environmental conditions. Weeds hardened by drought and/or extremely high temperatures are less susceptible to this product and the higher rates in the range are recommended under those conditions.

Turfgrass and Use Sites

QuickSilver Herbicide is intended to be applied by lawn care operators, maintenance applicators, and service technicians for use in ornamental lawns and turfgrass, as well as stone-covered yards established in institutional, ornamental, and residential/domestic sites. Institutional sites are defined as turf areas and stone-covered yards around properties or facilities providing a service to public or private organizations including, but not limited to hospitals, nursing homes, schools, museums, libraries, sports facilities, golf courses, and office buildings. Ornamental sites include turfgrass and stone-covered yards established around residences, parks, streets, retail outlets, cemeteries, industrial buildings and institutional buildings. Residential/domestic sites are defined as areas associated with household or home life including, but not limited to apartment complexes, condominiums, and patient care areas of nursing homes, mental institutions, hospitals, or convalescent homes.

Turfgrass Tolerance

Turfgrasses tolerant to application of QuickSilver Herbicide are listed below. FMC does not recommend application to turfgrasses not listed.

Cool Season Grasses (creeping bentgrass, colonial bentgrass, annual bluegrass, Kentucky bluegrass, fine fescues, red fescues, tall fescue, perennial ryegrass)

Established cool season grasses are generally tolerant to applications of QuickSilver Herbicide at labeled rates. Tall fescue may exhibit a slight yellowing discoloration occurring within 3 to 5 days after application under some conditions. Recovery typically occurs within 4 to 7 days. If such injury or any injury cannot be tolerated, apply to a small test area before treating large areas to assure tolerance of the host turf species.

Be aware of and observe all label restrictions regarding turf tolerance of companion products when QuickSilver Herbicide is tank mixed with another product.

Warm Season Grasses (common and hybrid bermudagrass, bahiagrass, buffalograss, centipedegrass, seashore paspalum, St. Augustine grass, zoysiagrass)

Established warm season grasses listed above are generally tolerant to applications of QuickSilver Herbicide but may be susceptible to transitory yellowing when they are under stress. Stress is typically associated with but not limited to extreme high or low temperatures, disease infection or insect infestation, extreme high or low moisture conditions, or transition into or out of dormancy.

Under such conditions injury in the form of transitory yellowing discoloration may occur within 3 to 7 days of application. If such injury or any injury cannot be tolerated, apply QuickSilver Herbicide in the manner you will be using it to a small test area before treating large areas to assure tolerance of the turf.

Be aware of and observe all label restrictions regarding turfgrass tolerance of companion products when QuickSilver Herbicide is tank mixed with another product.

Newly Seeded, Sodded or Sprigged turfgrass

QuickSilver Herbicide can be applied to the following species of turfgrass at 7 days or more after emergence for species established by both seeding and sprigging: Hybrid bermudagrass, common bermudagrass, St. Augustine, creeping bentgrass, tall fescue, perennial ryegrass and Kentucky bluegrass. Application to zoysiagrass should be delayed until at least 14 days after emergence to avoid extended discoloration. Slight discoloration may be observed immediately after application for Hybrid bermudagrass, however, normal turf color returns by 12 days after emergence if no other stresses are present. Areas treated with QuickSilver Herbicide may be seeded or overseeded one day following application.

Dormant Turf

Applications to dormant warm-season grasses are permitted. Avoid applications when warm-season grasses are transitioning into or out of dormancy.

Mixing Instructions

QuickSilver Herbicide is a unique liquid formulation utilizing an aggregate of mixed surfactants and is intended for dilution with water. Each water-soluble bag contains 5.0 ml of product. The outer package contains a liquid herbicide concentrate packaged in clear water-soluble bags. Do not allow the inner bags to become wet before adding to the spray tank. Do not handle the clear inner bags with wet hands or gloves. Do not carry the bags on your person in a manner that allows contact with perspiration. Do not store at temperatures below 32ºF (0ºC). Rough handling may cause breakage, especially at low temperatures. Allow to warm above 50ºF (10ºC) before use. Cooler water temperatures increase the time needed for the inner bag to dissolve completely.

QuickSilver Herbicide is to be diluted with water for spray application. Do not use strainers finer than 50 mesh size. Fill sprayer with one half of desired volume of water, add the water-soluble bag(s). After the bag(s) have dissolved, fill the sprayer to desired volume. For small hand-held sprayers, close and shake or agitate for 30 seconds before use in order to insure proper dissolution of the water-soluble bag.

Application Directions

Spray coverage

QuickSilver Herbicide is a contact herbicide with little or no residual activity. It produces herbicidal symptoms only in the portions of the target weeds with which it comes into direct contact. Therefore, to achieve maximum effectiveness of this product, select a spray volume and nozzle system that ensures thorough and uniform coverage and at the same time minimizes the spray fines. Spray droplets larger than 400 microns may reduce coverage and result in loss of weed control. Applications should be made using spray volumes of approximately 20–175 gallons per acre (one to eight gallons of water to treat 2,000 square feet). Use higher spray volumes when there is a dense weed population or a dense turfgrass canopy or where uniform coverage is difficult to obtain.

Spot Treatments (Applications with hand operated sprayers such as backpack sprayers, compression sprayers, knapsack sprayers) For spot treating weeds, other than moss, with hand-held or backpack sprayers add one (1) water-soluble bag of this product in one to eight gallons of water to treat 2000 square feet. Refer to Category 2 in the Weeds Controlled section to determine the appropriate rates for control of Silvery-thread moss. To avoid overdosing when using a hand-held wand, use a flat fan nozzle and maintain the nozzle at a uniform recommended height over the canopy. Avoid back-and-forth and side-to-side motion with the wand. Hold the wand stationary and move forward at a uniform pace over the area to be treated.

Use of Adjuvants

Addition of surface active agents (surfactants) or other adjuvants may improve effectiveness of QuickSilver Herbicide against weeds with difficult-to-wet leaf surfaces or weeds that are mature or hardened by harsh environmental conditions. Adjuvant materials may also reduce the selectivity to some turfgrass varieties and increase the potential for turf injury. Follow all adjuvant manufacturer use guidelines and also read and observe all companion product label statements, precautions and restrictions regarding use of adjuvants when QuickSilver Herbicide is used in tank mixtures with other products.

Limitations, Restrictions, and Exceptions

General Use Precautions

Avoid spray drift onto non-target susceptible plants such as vegetables, flowers, ornamentals, trees, shrubs and other desirable plants.

Do not apply this product to carpetgrass, dichondra, nor on lawns or turf where desirable clovers are present.

Do not apply when conditions are conducive to spray drift or poor spray coverage.

Do not apply more than 3 to 4 water-soluble bags of QuickSilver Herbicide per 2,000 square feet (0.09 to 0.12 lbs. a.i./acre) per application or more than 13 to 14 water-soluble bags per 2,000 square feet of QuickSilver Herbicide per acre (0.40 lbs. a.i./acre) per year. The minimum retreatment interval for sequential broadcast applications of this product is two (2) weeks.

Do not apply this product by aerial application.

Do not apply this product through any type of irrigation system.