Marengo Herbicide

DIRECTIONS FOR USE:

PRODUCT USE RESTRICTIONS:

• Do not exceed the maximum single application rates specified under each use.
• Do not exceed 18.5 fl oz per acre of Marengo for all applications within a 12 month period.
• Do not contaminate water intended for irrigation and domestic use.
• Do not apply within 25 feet of ponds, lakes, rivers, streams, wetlands, and habitat containing aquatic and semi-aquatic plants when Marengo is used on production nurseries and noncrop areas (excluding lawns).
• Do not apply Marengo through an irrigation or chemigation system.
• Do not apply Marengo by air.
• Follow use precautions and restrictions on this label and for all tank-mix partners, if mixing Marengo with other pesticides.
• Marengo is not for sale, distribution, or use in Nassau County or Suffolk County in New York State.

Not all products are registered in all states; please verify state registration of these products in your state before selling, distributing, or using.

DEACTIVATING Marengo

Activated charcoal has been shown to deactivate Marengo if applied within several days of application. Application of activated charcoal within 2 weeks of an application of Marengo will not reverse phytotoxic symptoms immediately, but it will aid in recovery over time. Follow directions for the amount of charcoal to apply on the label of the activated charcoal.

MIXING AND COMPATIBILITY:

Mixing Instructions:

Marengo should be added to the tank and agitated, prior to introduction of another pesticide. Mix the amount of Marengo needed for immediate application needs. Settling can occur if the spray mixture is allowed to sit over an extended period of time. Marengo is stable in spray solution for up to 48 hours after mixing. Re-agitate the spray solution before application.

Compatibility Testing With Other Pesticides:

Marengo is generally compatible with many pesticides and liquid fertilizers. A compatibility test should be conducted with any potential tank-mix partner with Marengo. Using a clear container, conduct the test as described below:

1. Fill the container three-quarters full with water.
2. Add the products to be tank-mixed in the following order: (a) wettable powders (b) dry flowable, (c) aqueous suspensions, (d) Marengo*, (e) liquids, (f) solutions and emulsifiable liquid concentrates, (g) micronutrients and liquid fertilizers.
3. Shake or stir after each addition to mix thoroughly.
4. After adding all ingredients, let the mixture stand for 15 minutes and look for separation, large flakes, precipitates, gels, and heavy oily film or other signs of incompatibility.
5. If the compatibility test shows signs of incompatibility, do not tank-mix the product tested with Marengo.

 * Note that a labeled spray rate for Marengo should be used in any compatibility test. Dilute from a concentrated suspension, or sample from a properly diluted spray solution.

SPRAYER CLEANUP PROCEDURE:

Spray equipment used to apply Marengo must be cleaned prior to use on sensitive ornamentals, or injury may result. Before and after using Marengo, triple rinse all mixing and spray equipment, including tanks, pumps, lines, filters, screens, and nozzles with a good quality tank cleaner on an approved rinse pad. Proper PPE must be worn while cleaning. Follow the directions below.

For each rinse cycle, complete the following:

• Completely drain the spray and mixing tanks.
• Rinse the spray tank inside and outside including all lines and screens. A rotating cleaning nozzle may be beneficial to dislodge any product from the sides of the tank.
• Fill the tank with water and cleaner.
• Circulate solution to ensure that the pumps, valves, and all lines are flushed.
• Remove and clean all filters, screens, and nozzles.
• Drain all cleaning solution and then rinse once more with clean water.
• Visually inspect the filters, screens, and tank walls to ensure that no product remains.
• Dispose of rinsate in an approved way.

RESISTANCE MANAGEMENT:

Marengo controls weeds by inhibiting cellulose biosynthesis. Cellulose is a component in the formation of plant cell walls. Marengo is classified as a Group 29 herbicide. No known resistance to Marengo exists, and there are no known instances of cross-resistance between Marengo and other classes of herbicides or other modes of action. Performance of Marengo is not affected by the presence of biotypes resistant to glyphosate, triazines, ALS inhibitors, mitotic inhibitors, growth regulators, or herbicides with other modes of action. Prolonged use of any herbicide with the same mode of action may lead to selection of resistant weed populations and a reduction in efficacy. Rotation of herbicides with an alternate mode of action can help prevent the development and spread of resistant weed populations. If resistance to Marengo is suspected, use a herbicide with an alternate mode of action. The decision to use a particular herbicide should always be based on an IPM program and involve consideration of all cultural practices and other pesticides in use.

Weeds Controlled or Suppressed by Marengo**

Broadleaf Weeds:

American black nightshade, American burnweed (Fireweed), Bittercress, Black medic*, Buckwheat (Wild), California burclover, Canada thistle (Common), Chickweed (Common), Chickweed (Mouse-ear), Clover (White), Corn speedwell, Cudweed (Linear-leaf/purple), Curly dock, Dandelion (Cat’s Ear), Dandelion (Common), Eclipta, Evening primrose (Common), Evening primrose (Cutleaf), False chamomile*, Filaree (Redstem), Florida pusley, Groundsel (Common), Hairy fleabane, Hairy nightshade, Henbit, Horseweed/Marestail, Kochia, Lambsquarters (Common), Lawn burweed, Little mallow, London rocket*, Longstalked phyllanthus, Mustard (Black)*, Mustard (Wild), Parthenium, Pigweed (Prostrate), Pigweed (Redroot), Plantain (Buckhorn), Plantain (Paleseed), Prostrate knotweed, Prostrate spurge, Puncturevine, Purslane (Common), Ragweed (Common)*, Spurge (Spotted), Tassel flower, Redmaids, Sesbania (Hemp)*, Shepherd's-purse, Sida (Prickly/Teaweed)*, Southern brassbuttons*, Sowthistle (Annual), Sunflower* (Common), Swinecress, Tropic ageratum, Velvetleaf*, Vetch (Purple)*, Wild carrot*, Willowherb, Woodsorrel (Yellow)*, Woodsorrel/Oxalis*.

Grasses, Monocots, and Sedges:

Annual bluegrass/ ‘Poa’, Annual kyllinga, Barnyardgrass (Common), Cheatgrass, Crabgrass, Crabgrass (Henry), Crabgrass (Large/Hairy), Crabgrass (Smooth), Doveweed, Foxtail (brome), Foxtail (Giant), Foxtail (Green), Foxtail (Yellow), Goosegrass, Guineagrass, Kyllinga (Fraqrant/Annual), Mouse barley, Red brome, Rice flatsedge, Ryegrass (Italian), Ryegrass (Perennial), Sandbur, Sedge (Annual)***, Tufted lovegrass.

* Weeds suppressed by Marengo
** Higher labeled rates should be used if weed pressure is historically high or longer residual control is desired (See Use Rates in the Marengo chart). Weed control can also be achieved with multiple applications of Marengo. Do not exceed a total of 18.5 fl oz per acre per year with multiple applications.
*** Marengo only controls sedges and annual kyllinga emerging from seed. It does not control perennial sedge emerging from nutlets or perennial forms of kyllinga.

ORNAMENTALS, CHRISTMAS TREES, AND CONIFER PLANTATIONS:

Marengo may be applied for pre-emergent weed control in production ornamentals in outdoor nurseries, shadehouses, hoophouses, Christmas trees, and conifer plantations. Apply Marengo as a directed spray, prior to weed seed germination to the soil surface around dormant or actively growing ornamentals as listed in the table below. Apply Marengo to established ornamentals. If the grower is uncertain about ornamental establishment after transplanting, wait 2 months before applying Marengo.

USE RESTRICTIONS FOR Marengo ON PRODUCTION ORNAMENTALS, CHRISTMAS TREES, AND CONIFERS:

• Do not exceed the maximum single application rates specified under each Ornamental use.
• Do not exceed a total of 18.5 fl oz of Marengo per acre in a 12 month period.
• Do not allow spray to contact foliage. Marengo may cause localized injury to the foliage, especially young leaf tissue. If the spray should contact the foliage, remove affected foliage or wash off immediately.
• Do not use Marengo around bedding plants (annuals and herbaceous plants not specified, or not listed as tolerant on this label).
• Do not use Marengo around bearing fruit and nut trees.
• Do not use Marengo around non-bearing fruit trees unless they are at least 1 year old (citrus), 5 years old (grape vines) and 3 years old (all others). Non-bearing trees are defined as trees that will not bear fruit until at least 1 year after treatment.
• Do not use Marengo within the dripline of bearing fruit and nut trees.
• Do not mix Marengo into the soil. Cultivating or disturbing the soil surface after application may reduce weed control activity.
• If transplanting mature plants listed as tolerant on this label into soil treated with Marengo within the preceding 12 months, discard existing soil from the planting hole and add new soil around roots to minimize effects on plant establishment.
• Do not use Marengo on ornamentals being grown in a greenhouse.
• Do not use Marengo on nursery seedbeds, rooted cuttings or young plants in liners.
• Do not apply Marengo to ornamentals growing in containers except pot-in-pot ornamentals.
• Do not apply Marengo to ornamental bulbs in production fields.
• Do not apply Marengo to ornamental bulbs in commercial fields after they have emerged.
• Do not apply Marengo to herbaceous perennials (e.g. hosta) after they have emerged.
• Do not apply Marengo over-the-top of ornamentals.
• Do not apply Marengo to budded grafts or graft unions as this could cause plant injury or death.
• Do not apply Marengo by air.

USE OF Marengo ON ORNAMENTALS IN COARSE AND SANDY SOILS:

Soil conditions can affect the tolerance of ornamentals to Marengo. Excessively coarse or sandy soils may allow for downward movement of Marengo into the root zone and cause significant root damage and phytotoxicity. Coarse soils, for example, may include significant quantities of sand, gravel, decomposed granite, and ground cinders. Prior to application of Marengo on these soils, confirm soil texture with a soil test. Ornamentals grown in soil exceeding 80% sand or 20% gravel may be at risk. If Marengo is to be applied in these soils, evaluate tolerance of a few plants of each ornamental in Marengo treated soil for 2-3 months prior to a large scale application.

SYMPTOMS OF Marengo INJURY ON ORNAMENTALS:

Marengo may injure sensitive ornamentals by damaging roots or leaves. Plant foliage damaged by root absorption will appear stunted, deformed, and may not recover. If Marengo is allowed to contact leaves, leaf symptoms including leaf spot, leaf discoloration, and leaf curl may appear. Symptoms appear within several days after application. Leaves formed after appearance of symptoms may recover. Users must assess the severity of any symptoms on cultivars not listed on this label, before proceeding with large-scale applications of Marengo. The user assumes all responsibility for damage on cultivars not listed on this label.

PRODUCTION ORNAMENTAL USES

Marengo provides up to 8 months of weed control with a single application. The exact length of control depends on many environmental factors as well as the weeds to be controlled and the weed pressure. Apply Marengo as a directed spray to the soil surface only to established (rooted) plants in the soil or in pots and not to newly rooted cuttings/or seedling beds in production nurseries. Do not apply Marengo to newly rooted cuttings/or seedling beds. To avoid root damage, apply Marengo around transplants when the plant is well established and the soil has firmly settled around the root area. Irrigation or rainfall will help to settle the soil and seal surface cracks. Apply Marengo around dormant plants. If applied after dormancy, care should be taken not to contact expanding buds or new leaves. Applications of Marengo should only be made to ornamentals listed on this label. Marengo should be applied to soil free of weeds, debris, and soil clods for optimum efficacy. Herbicidal efficacy may be reduced if soil is disturbed after application.

Application of Marengo to deciduous foliage or green bark may result in unacceptable injury. Apply Marengo to established ornamentals. If the grower is uncertain about ornamental establishment after transplanting, wait 2 months before applying Marengo.

AMOUNT TO USE: Apply Marengo as a broadcast, directed spray at 7.5-15.5 fl oz of Marengo per acre (0.17 -0.36 fl oz per 1,000 sq ft) around ornamentals in 20-100 gallons of water per acre (0.5-2.3 gallons of water per 1,000 sq ft). When applying Marengo with a backpack sprayer, follow all above restrictions.

To activate Marengo for maximum herbicidal benefit, irrigate the area treated with Marengo to move the herbicide into the soil within 21 days after application. With dry soil, use a minimum of 0.25 inches of irrigation water. With soil at or greater than field capacity, reduce the amount of irrigation water. In either case, do not create conditions that cause visible run-off of irrigation water. Adequate rainfall following an application will negate the need for irrigation.

A subsequent application of Marengo can be made within 90 days after the initial application provided that the maximum allowed rate does not exceed 18.5 fl oz per acre in a 12-month period.

CONIFERS AND CHRISTMAS TREES

Marengo may be used for pre-emergence weed control in conifer nurseries and Christmas tree farms. Marengo may be applied as a directed spray to soil surrounding established plants. Avoid contacting plant stems and leaves with the directed spray solution as injury may occur. Established plants are transplants that are actively growing and where the soil has settled. Do not apply to seedlings or seedling beds. Apply 7.5-15.5 fl oz of Marengo per acre for these uses. Do not exceed 18.5 fl oz of Marengo per acre in a growing season.

Marengo may be tank-mixed with products containing the following active ingredients labeled for use in conifers: glyphosate or glufosinate (FINALE). Do not apply tank-mixes of Marengo with these active ingredients to conifer and Christmas tree foliage. Follow use restrictions on all labels.

NON-SELECTIVE USES:

HARDSCAPES:

Marengo may be used to maintain bare ground in non-crop areas. These include but are not limited to gravel rocky or sandy areas. All weeds and debris should be removed from these areas to be treated for optimum control. Observe all restrictions and tolerances for applications of Marengo around ornamentals listed on this label.

Apply 9 - 18.5 fl oz of Marengo per acre with uniform coverage to target area. Use a minimum spray volume of 10-20 gallons per acre.

If weeds are present at the time of application, tank-mix a post-emergent herbicide such as glyphosate or Finale with Marengo. Observe all use restrictions on this label and on the label of the tank-mix partner. Adequate irrigation or rainfall after application of Marengo will provide maximum weed control.

ORNAMENTAL PRODUCTION FACILITIES:

Marengo may be used in ornamental production facilities such as greenhouses (floors only), areas covered by landscape fabric, hoophouses, lathhouses and shadehouses to provide bare ground and general weed control beneath benches and potted plants. Marengo may injure the foliage of ornamentals; prevent spray from contacting foliage. Make applications to these sites during clean up, sanitation and preparation prior to plant production. Apply 9 - 18.5 fl oz product per acre with uniform coverage to target area. Use a minimum spray volume of 20 gallons per acre.

If weeds are present at the time of application, tank-mix a post-emergent herbicide such as Finale with Marengo. Observe all use restrictions on this label and on the label of the tankmix partner. Water in Marengo after application and allow applied surface to dry prior to introducing plants. For outdoor applications, containers can be moved onto the treated ground bed areas after irrigation or rainfall and once the treated surface has dried.

Do not mix with products containing chlorine bleach products. When tank mixing with other products, it is the responsibility of the end-user/applicator to ensure that the tank-mix partner is registered in the state for the application being made.

ENVIRONMENTAL HAZARDS:

This product is toxic to fish, aquatic invertebrates, and plants. Do not apply directly to water, or to areas where surface water is present or to intertidal areas below the mean watermark. Do not contaminate water when disposing of equipment rinsate or washwater. This product may enter water through spray drift or runoff. Follow directions for use to avoid spray drift and runoff. A level well maintained vegetative buffer strip between areas to which this product is applied and surface water features including ponds, streams, and springs will reduce the potential for getting into water from rainfall-runoff. Runoff of this product will be reduced by avoiding applications when rainfall is forecasted to occur within 48 hours.