2,4-D dimethylamine salt (DMA 4 IVM, Base Camp and others)
Rate 2 to 4 pints/A product in 20 to 100 gal/A
Time Apply in spring or early summer when aquatic weeds appear, prior to bud or bloom.
Remarks Repeat as necessary to kill regrowth or missed plants; use 4 pints/A rate when plants are mature or dense.
Caution Maximum of 8 pints/A per application; limited to 2 applications per season, a minimum of 21 days apart. Toxic to fish and aquatic invertebrates. Do not treat areas free of weeds. If weeds are abundant, consider partial treatments to avoid fish kill (due to low oxygen from decomposing weeds). Do not use water for irrigation if approved assay indicates 2,4-D concentration is above 0.1 ppm (100 ppb). Do not use treated water for drinking if approved assay indicates 2,4-D concentration is above 0.07 ppm (70 ppb). See label for sampling requirements and posting requirements. Do not use on small canals with flow rates < 10 cfs where water will be used for drinking water purposes. Do not overspray to opposite bank or allow boom spray to be directed onto water surface; allow no more than 2-foot overspray onto water with an average of less than one foot of overspray.
Site of action Group 4: synthetic auxin
Chemical family Phenoxy acetic acid
bispyribac-sodium (Tradewind)
Rate 0.05 to 0.1 lb ai/A (1 to 2 oz/A)
Time Apply in spring or early summer to the foliage of actively growing weeds.
Remarks When applying to dense foliage of actively growing weeds, a second application may be required to ensure adequate coverage. Use with an adjuvant approved for aquatic use. Allow 30 days between applications, apply no more than 8 oz of product per acre per year, and do not exceed 4 applications per year. Bispyribac may be mixed with other registered foliar applied aquatic herbicides for enhanced control of floating and emergent weeds.
Caution With aerial applications do not spray within 200 feet of dwellings, adjacent sensitive crops or environmentally sensitive areas. Consult label for water use restrictions.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Pyrimidinylthiobenzoate
carfentrazone (Stingray)
Rate 0.05 to 0.2 lb ai/A
Time Apply in spring or early summer to actively growing weeds.
Remarks Inject into water with a boat-mounted injection system. Material may be applied as a surface spray only in combination with a suitable polymer or similar adjuvant that will ensure rapid sinking and mixing of the spray mix. Apply only to water with little or no outflow.
Caution Moderately toxic to fish. Do not exceed 200 ppb in treated water. Do not apply within 1/4 mile of functioning potable water intakes in flowing or standing water. To avoid oxygen depletion and potential fish kills, treat no more than half the waterbody at a time; wait a minimum of 14 days before treating the remaining area. Consult label for water use restrictions.
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Triazinone
glyphosate (Rodeo, AquaNeat, AquaPro, AquaMaster, Cinco, Accord Concentrate and others)
Rate 0.75 to 3.75 lb ae/A (1.5 to 7.5 quarts/A) applied as a broadcast spray or 0.75 to 2.0% solution in water applied through hand-held or high-volume equipment
Time Apply when weeds and brush are actively growing.
Remarks See label for application rate and growth stage of weed and brush species. Floating mats of vegetation may require re-treatment. If emergent infestations require treating the total surface of impounded water, treating the area in strips may avoid oxygen depletion, due to decaying vegetation, and prevent subsequent fish kill. If water is in the area to be sprayed, add a surfactant labeled for use in water at the manufacturers' surfactant label recommendations. Surfactant must be at least 80% ai. In dry ditches or after drawdown, allow seven days after treatment before reintroducing water; treat within one day after drawdown to ensure weeds are actively growing. Apply as a 33% solution through wiper-type applicators. May be applied through hand-held or high-volume equipment as a 0.75 to 1.5% solution.
Caution Rain within 6 hours after application may reduce effectiveness. Do not apply within 0.5 mile upstream of potable water intakes. Apply to moving bodies of water only while traveling upstream. Do not overlap bank side applications more than 1 foot into open water. Do not exceed 3.75 lb ae/A in a single application being made over water. Take care to avoid drift to desirable plants. With bankside applications, do not overlap more than one foot into open water. Do not spray where weeds do not exist.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
florpyrauxifen-benzyl (ProcellaCOR EC)
Rate For all foliar applications, apply ProcellaCOR EC at 5 to 10 Prescription Dose Units (PDU) per acre. Use of a surfactant is required for all foliar applications of ProcellaCOR EC. Refer to the surfactant label for use directions. ProcellaCOR EC may be applied more than once per growing season to meet management objectives. 0.0052 lb florpyrauxifen-benzyl per PDU.
Time For best results, apply to actively growing plants.
Remarks Use only surfactants that are approved or appropriate for aquatic use. Methylated seed soil (MSO) is a recommended surfactant and is typically applied at 1% v/v.
Caution Do not exceed 10 PDU per acre during any individual application or 20 PDU total per acre, per year from all combined treatments. Do not use treated water for any form of irrigation. Irrigating with treated water may injure crops. See label for irrigation times after application. Do not permit ProcellaCOR EC to come into contact during an application with any desirable broadleaf plants, as serious injury may occur.
Site of action Group 4: auxin herbicide chemotype
Chemical family Arylpicolinate
imazamox (Clearcast)
Rate 0.125 to 0.5 lb ai/A (16 to 64 oz product/A)
Time Apply as a foliage spray to actively growing emergent and floating plants.
Remarks Rate depends on species to be controlled. Postemergence applications require adding a spray adjuvant approved for use in aquatic sites. There are no restrictions on livestock watering, swimming, fishing, or domestic use as long as the setback restriction is observed, or for agricultural sprays.
Caution Do not use treated water to irrigate greenhouses, nurseries, or hydroponics. Do not use treated water for other irrigation purposes unless concentrations in water are equal to or less than 50 ppb. Note label restrictions on setback restrictions to potable water intakes.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
imazapyr, isopropylamine salt (Arsenal, Habitat, Polaris AQ)
Rate 0.5 to 1.5 lb ae/A (2 to 6 pints/A), applied with surface or helicopter equipment in minimum of 2 gal water/A. For low volume foliar applications, use 0.5 to 5% concentration (without applying more than 6 pints/A per year).
Time Apply to vigorously growing emergent and floating vegetation.
Remarks Controls several annual, biennial, and perennial grass and broadleaf species. Rate depends on weed species and growth stage at time of application. Postemergence applications require adding a spray adjuvant (such as a nonionic surfactant or methylated seed oil) approved for use in aquatic sites. Controls emerged and floating vegetation that has most of its foliage above the water surface. No restrictions on recreational or livestock use of treated water. Moisten, but do not drench target vegetation.
Caution Do not apply more than 1.5 lb ae/A (6 pints/A product) per year. Do not apply within 1.0 mile of an active irrigation water intake during irrigation season; applications of < 1 mile may be made during off-season, provided irrigation will remain inactive for 120 days minimum following treatment or until laboratory analysis shows imazapyr levels < 1.0 ppb.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Imidazolinone
topramezone (Oasis)
Rate For foliar applications apply up to a maximum of 16 fl oz/acre (0.35 lb ai free acid/A)
Time Apply only to actively growing weeds.
Remarks Use with an aquatic approved surfactant
Caution See label for irrigation restrictions.
Site of action Group 27 4-HPPD inhibitor
Chemical family Pyrazolone
triclopyr (Renovate 3)
Rate 0.75 to 6 lb ae/A; 0.75 to 2.5 ppm ae concentration in water
Time Apply to actively growing broadleaf weeds and woody plants.
Remarks Use a labeled nonionic surfactant. Use the higher rate when plants are mature or weed mass is dense or for difficult-to-control weeds. Repeat as necessary to control re-growth and plants missed in the previous application. There are no restrictions on recreation in the treated area, including swimming and fishing, or on livestock consumption of water.
Caution Do not apply when conditions favor drift to susceptible vegetation. Do not exceed 6 lb ae/A triclopyr (8 quarts/A of Renovate) per annual growing season. Consult label for setback distances from potable water intakes when applying to control floating and emerged weeds in lakes, reservoirs, or ponds.
Site of action Group 4: synthetic auxin
Chemical family Pyridine