STUMP AND CUT STEM TREATMENTS - FRILL OR GIRDLE TREATMENTS
Arsenal herbicide is an aqueous solution to be mixed with water and a surfactant and applied as a spray solution to control undesirable vegetation growing within specified aquatic sites, forestry sites, pasture/rangeland and nonagricultural lands. Aquatic sites consist of standing and flowing water, estuarine/marine, wetland, and riparian areas.
Nonagricultural lands include private, public and military lands as follows: uncultivated nonagricultural areas (including airports, highway, railroad and utility rights-of-way, and sewage disposal areas); uncultivated agricultural areas - noncrop producing (including farmyards, fuel storage areas, fence rows, nonirrigation ditchbanks, and barrier strips); industrial sites - outdoor (including lumberyards, pipeline and tank farms); and natural areas (including wildlife management areas, wildlife openings, wildlife habitats, recreation areas, campgrounds, trailheads, and trails).
Arsenal may also be used for the release of unimproved Bermudagrass and Bahiagrass, for bareground weed control, and for use under certain paved surfaces.
Arsenal will control most annual and perennial grass and broadleaf weeds in addition to many brush and vine species with some residual control of undesirable species that germinate above the waterline. Arsenal is readily absorbed through emergent leaves and stems and is translocated rapidly throughout the plant with accumulation in the meristematic regions. For maximum activity, weeds should be growing vigorously at the time of application, and the spray solution should include a surfactant (see Adjuvants section for specific use directions). Treated plants stop growing soon after spray application. Chlorosis appears first in the newest leaves, and necrosis spreads from this point. In perennials, the herbicide is translocated into and kills underground or submerged storage organs, which prevents regrowth. Chlorosis and tissue necrosis may not be apparent in some plant species until 2 or more weeks after application. Complete kill of plants may not occur for several weeks. Arsenal applications are rainfast 1 hour after treatment.
Product Use and Restrictions
Applications may be made for control of undesirable vegetation growing within specified aquatic sites, forestry sites, pasture/rangeland and nonagricultural lands. Aquatic sites consist of standing and flowing water; estuarine/marine, wetland, and riparian areas; for control of most annual and perennial grass weeds, broadleaf weeds, vines and brambles, and hardwood brush and trees for forestry site preparation and release of conifers from woody and herbaceous competition. Arsenal may also be used for selective woody and herbaceous weed control in natural regeneration of certain conifers (see Conifer Release Treatment).
Nonagricultural lands include private, public and military lands as follows: uncultivated nonagricultural areas (including airports, highway, railroad and utility rights-of-way, and sewage disposal areas); uncultivated agricultural areas -noncrop producing (including farmyards, fuel storage areas, fence rows, nonirrigation ditchbanks, and barrier strips); industrial sites - outdoor (including lumberyards, pipeline and tank farms); and natural areas (including wildlife management areas, wildlife openings, wildlife habitats, recreation areas, campgrounds, trailheads, and trails).
Restrictions and Limitations
- DO NOT use on food crops.
- DO NOT apply this product within 1/2 mile upstream of an active potable water intake in flowing water (i.e. river, stream, etc.) or within 1/2 mile of an active potable water intake in a standing body of water, such as a lake, pond, or reservoir.
- DO NOT apply to water used for irrigation except as described in Product Use and Restrictions section of this label.
- Keep from contact with fertilizers, insecticides, fungicides, and seeds.
- DO NOT drain or flush equipment on or near desirable trees or other plants, or on areas where their roots may extend, or in locations where the treated soil may be washed or moved into contact with their roots.
- DO NOT use on lawns, walks, driveways, tennis courts, or similar areas.
- DO NOT side trim desirable vegetation with this product unless severe injury and plant death can be tolerated.
Prevent drift of spray to desirable plants.
- Clean application equipment after using this product by thoroughly flushing with water.
Nonagricultural Lands and Forestry Sites
- DO NOT apply more than 1.5 lbs acid equivalent (ae) imazapyr (equivalent to 96 fl ozs of Arsenal herbicide) per acre per year.
- For spot treatment only.
- DO NOT treat more than 1/10 of the available area to be grazed or cut for hay.
- DO NOT apply more than 0.75 lb ae imazapyr (equivalent to 48 fl ozs of Arsenal) per acre per year.
- DO NOT apply more than 1.5 lbs ae imazapyr (equivalent to 96 fl ozs of Arsenal) per acre per year.
- Public waters - Application of Arsenal to water can only be made by federal or state agencies, such as Water Management District personnel, municipal officials, and the U.S. Army Corps of Engineers, or those applicators who are licensed or certified as aquatic pest control applicators and are authorized by the state or local government.
Treatment to other than non-native invasive species is limited to only those plants that have been determined to be a nuisance by a federal or state government entity.
- Permitting - Consult local state fish and game agency and water control authorities before applying this product to public water. Permits may be required to treat such water.
- Private waters - Applications may be made to private waters that are still, such as ponds, lakes, and drainage ditches where there is minimal or no outflow to public waters.
- Aerial application - Aerial application to aquatic sites is restricted to helicopter only.
- Irrigation water - Application to water used for irrigation that results in Arsenal residue greater than 1.0 ppb MUST NOT be used for irrigation purposes for 120 days after application or until Arsenal residue levels are determined by laboratory analysis or other appropriate means of analysis to be 1.0 ppb or less. When applications are made within 500 feet of an active irrigation intake,
DO NOT irrigate for at least 24 hours following application to allow for dissipation.
Recreational Use of Water in Treatment Area
There are no restrictions on the use of water in the treatment area for recreational purposes, including swimming and fishing.
Livestock Use of Water in/from Treatment Area
There are no restrictions on livestock consumption of water from the treatment area.
Restrictions for Potable Water Intakes
DO NOT apply Arsenal directly to water within 1/2 mile upstream of an active potable water intake in flowing water (i.e. river, stream, etc.) or within 1/2 mile of an active potable water intake in a standing body of water such as a lake, pond, or reservoir. To make aquatic applications around and within 1/2 mile of active potable water intakes, the water intake must be turned off during application and for a minimum of 48 hours after application. These aquatic applications may be made only in cases where there are alternative water sources or holding ponds that would permit turning off an active potable water intake for a minimum period of 48 hours after applications.
NOTE: Existing potable water intakes that are no longer in use, such as those replaced by connections to wells or a municipal water system, are not considered to be active potable water intakes. This restriction does not apply to intermittent, inadvertent overspray of water in terrestrial use sites.
Quiescent or Slow-moving Waters
In lakes and reservoirs, DO NOT apply Arsenal within 1 mile of an active irrigation water intake during the irrigation season. Applications less than 1 mile from an active irrigation water intake may be made during the off-season if the irrigation intake will remain inactive for a minimum of 120 days after application or until Arsenal residue levels are determined by laboratory analysis or other appropriate means of analysis to be 1.0 ppb or less.
Precautions for Avoiding Injury to Nontarget Plants
Untreated desirable plants can be affected by root uptake of Arsenal herbicide from treated soil. Injury or loss of desirable plants may result if Arsenal is applied on or near desirable plants, on areas where their roots extend, or in locations where the treated soil may be washed or moved into contact with their roots. When making application along shorelines where desirable plants may be present, use caution to avoid spray contact with their foliage or spray application to the soil in which they are rooted.
Shoreline plants that have roots which extend into the water in an area where Arsenal has been applied generally will not be adversely affected by uptake of the herbicide from the water.
If treated vegetation is to be removed from the application site, DO NOT use the vegetative matter as mulch or compost on or around desirable species.
Managing Off-target Movement
- Applicators are required to use a coarse or coarser droplet size (ASABE S572) or, if specifically using a spinning atomizer nozzle, applicators are required to use a volume mean diameter (VMD) of 385 microns or greater for release heights below 10 feet. Applicators are required to use a very coarse or coarser droplet size or, if specifically using a spinning atomizer nozzle, applicators are required to use a VMD of 475 microns or greater for release heights above 10 feet. Applicators must consider the effects of nozzle orientation and flight speed when determining droplet size.
- Applicators are required to use upwind swath displacement.
- The boom length must not exceed 60% of the wingspan or 90% of the rotor-blade diameter to reduce spray drift.
- Applications with wind speeds less than 3 mph and with wind speeds greater than 10 mph are prohibited.
- Applications into temperature inversions are prohibited.
Ground Boom Application
- Applicators are required to use a nozzle height below 4 feet above the ground or plant canopy and coarse or coarser droplet size (ASABE S572) or, if specifically using a spinning atomizer nozzle, applicators are required to use a volume mean diameter (VMD) of 385 microns or greater.
- Applications with wind speeds greater than 10 mph are prohibited.
- Applications into temperature inversions are prohibited.
Arsenal herbicide may be selectively applied using low volume directed application techniques or may be broadcast-applied using ground equipment, watercraft, or aircraft. Aerial applications to aquatic sites must be made by helicopter. In addition, Arsenal may also be applied using cut-stump, cut-stem, and frill or girdle treatment techniques within nonagricultural lands, pasture/rangeland, and aquatic sites; see Aerial Application and Ground Application sections for additional details.
All precautions must be taken to minimize or eliminate spray drift. Both fixed-wing aircraft and helicopters can be used to apply Arsenal on nonagricultural lands, but only helicopters can be used for aquatic applications. DO NOT make applications by fixed-wing aircraft or helicopter unless appropriate buffer zones can be maintained to prevent spray drift out of the target area; or when treating open tracts of land, spray drift as a result of fixed-wing aircraft application can be tolerated. Aerial equipment designed to minimize spray drift, such as a helicopter equipped with a Microfoil boom, Thru-Valve boom, or raindrop nozzles, must be used and calibrated. Except when applying with a Microfoil boom, a drift control agent may be added at the specified label rate. DO NOT side trim with Arsenal unless death of treated tree can be tolerated.
Uniformly apply the specified amount of Arsenal in 2 to 30 gallons of water per acre. A foam-reducing agent may be added at the specified label rate, if needed.
Thoroughly clean application equipment, including landing gear, immediately after use of this product. Prolonged exposure of this product to uncoated steel (except stainless steel) surfaces may result in corrosion and failure of the exposed part. The maintenance of an organic coating (paint) may prevent corrosion.
Low-volume Foliar Application
Use equipment calibrated to deliver 5 to 20 gallons of spray solution per acre. To prepare the spray solution, thoroughly mix in water 0.5% to 5% Arsenal plus surfactant; see the Adjuvants section of this label for specific use directions. A foam-reducing agent may be applied at the specified label rate, if needed. For difficult-to-control species (see Aquatic Weed Control and Terrestrial Weed Control sections for relative susceptibility of weed species), use the higher concentrations of herbicide and/or spray volumes, but DO NOT apply more than 3 quarts of Arsenal per acre in aquatic sites and nonagricultural lands and 1.5 quarts per acre in pasture/rangeland. Excessive wetting of foliage is not necessary.
For low-volume foliar application, select proper nozzles to avoid overapplication. Proper application is critical to ensure desirable results. Best results are achieved when spray covers the crown and approximately 70 percent of the plant. The use of an even, flat-fan tip with a spray angle of 40 degrees or less will aid in proper deposition.
Appropriate tip sizes include 4004E or 1504E. For a straight-stream and cone pattern, adjustable cone nozzles, such as 5500 X3 or 5500 X4, may be used. Attaching a rollover valve onto a Spraying Systems Model 30 gunjet or other similar spray gun allows for the use of both flat-fan and cone tips on the same gun.
Moisten, but DO NOT drench target vegetation causing spray solution to run off.
Low-volume Foliar Application with Backpack. For low-growing species, spray down on the crown, covering crown and penetrating approximately 70% of the plant.
For target species 4 to 8 feet tall, swipe the sides of target vegetation by directing spray to at least 2 sides of the plant in smooth vertical motions from the crown to the bottom.
Make sure to cover the crown whenever possible.
For target species over 8 feet tall, lace sides of target vegetation by directing spray to at least 2 sides of the target in smooth zigzag motions from crown to bottom.
Low-volume Foliar Application with Hydraulic Handgun Application Equipment. Use the same technique as described for Low-volume Foliar Application with Backpack.
For broadcast application, simulate a gentle rain near the top of target vegetation allowing spray to contact the crown and penetrate the target foliage without falling to the understory. Herbicide spray solution that contacts the understory may result in severe injury or death of plants in the understory.
High-volume Foliar Application
For optimum performance when spraying medium-density to high-density vegetation, use equipment calibrated to deliver up to 100 gallons of spray solution per acre (GPA).
Spray solutions exceeding 100 GPA may result in excessive spray runoff, causing increased ground cover injury and injury to desirable species.
To prepare the spray solution, thoroughly mix Arsenal in water and add a surfactant; see Adjuvants section for specific use directions and rates for surfactants. A foam reducing agent may be added at the specified label rate, if needed. For difficult-to-control species (see Aquatic Weed Control and Terrestrial Weed Control sections for relative susceptibility of weed species), use the higher concentrations of herbicide and/or spray volumes, but DO NOT apply more than 3 quarts of Arsenal per acre in aquatic sites and nonagricultural lands and 1.5 quarts per acre in pasture/rangeland. Uniformly cover the foliage of the vegetation to be controlled, but DO NOT apply to runoff. Excessive wetting of foliage is not necessary.
DO NOT side trim with Arsenal herbicide unless severe injury or death of the treated tree can be tolerated. Arsenal is readily translocated and can result in death of the entire tree.
Arsenal may be used to control undesirable woody vegetation by applying the Arsenal solution to the cambium area of freshly cut stump surfaces or to fresh cuts on the stem of target woody vegetation. Application can be made any time of the year except during periods of heavy sap flow in the spring. DO NOT overapply solution causing runoff from the cut surface.
Injury may occur to desirable woody plants if shoots extend from the same root system or their root systems are grafted to those of the treated tree.
Frill or Girdle Treatments
Using a hatchet, machete, or chainsaw, make cuts through the bark and completely around the tree to expose the cambium. The cut should angle downward extending into the cambium enough to expose at least 2 growth rings. Using a spray applicator or brush, apply a 25% to 100% solution of Arsenal into each cut until thoroughly wet. Avoid applying so much herbicide that runoff to the ground or water occurs.