DuPont™ Products for Vegetation Management Specialists and Applicators John D. Cantlon*, Ronnie G. Turner, Jerry R. Pitts DuPont Vegetation Management Memphis, TN Throttle™ XP Herbicide Throttle™ XP is a new bareground residual herbicide effective in controlling resistant weed biotypes of kochia and Russian thistle along with problem broadleaf weeds such as tall waterhemp and thistles. Common Name with Registration Number: Chlorsulfuron Sulfometuron Sulfentrazone 352 - 654 352 – 601 279 - GEIE General Information: DuPont™ Throttle® XP herbicide is formulated as a water dispersible granule to be mixed in water and applied as a spray on non-crop sites for the control of susceptible annual/perennial broadleaf and grass weeds. Throttle™ XP is recommended for general weed control on private, public and military lands as follows: uncultivated non-agricultural areas (such as, airports, highway, railroad and utility rights-of-way, sewage disposal areas); uncultivated agricultural areas (non-crop producing, which includes: farmyards, fuel storage areas, fence rows, barrier strips); industrial sites (outdoor, such as, lumberyards, pipeline and tank farms). General Information: This product may be applied on non-crop sites that contain areas of temporary surface water caused by collection of water in equipment ruts or in other depressions created by management activities. It is permissible to treat intermittently flooded low lying areas, seasonally dry flood plains and transitional areas between upland and lowland sites when no water is present. It is also permissible to treat marshes, swamps and bogs after water has receded, as in seasonally dry flood deltas. Do not make applications to natural or man-made bodies of water such as lakes, reservoirs, ponds, streams and canals. Mode of Action Throttle® XP is a blended product that employs two distinctly different modes of action (MOA’s) in controlling susceptible broadleaf weeds, grasses and sedges. The sulfentrazone portion of the product inhibits protoporphyrinogen oxidase (protox), a pivotal enzyme in chlorophyll biosynthetic pathway causing a build-up of peroxide-like compounds, causing the plant cell membrane to rupture. The chlorsulfuron and sulfometuron portions inhibit acetolactate synthase or ALS, a key enzyme in plants needed in the biosynthesis of the branched amino acids isoleucine, leucine and valine. Animals do not possess this enzyme to synthesize proteins. Acute Toxicity Chlorsulfuron 5544 mg/kg - oral - rodent – 3400 mg.kg - dermal toxicity – rabbit – 5.9 mg/L inhalation toxicity – rodent – None - skin irritation – rabbit – Moderate – eye irritation – rabbit – None - skin sensitization - guinea pig Sulfometuron 5000 mg/kg - oral - rodent – 2000 mg.kg - dermal toxicity – rabbit – 5.0 mg/L inhalation toxicity – rodent – None - skin irritation – rabbit – Mild – eye irritation – rabbit – None - skin sensitization - guinea pig Sulfentrazone 2689 mg/kg - oral - rodent – 2000 mg.kg - dermal toxicity – rabbit – 4.13 mg/L inhalation toxicity – rodent – None - skin irritation – rabbit – Mild – eye irritation – rabbit – Negative - skin sensitization - guinea pig Use Rate and Biological Activity Throttle® XP is to be applied at a use rate of 12.5 ounces of product per acre. When applied as a spray, Throttle® XP is absorbed by both roots and foliage of plants, rapidly inhibiting the growth of susceptible weeds. Warm, moist conditions following application accelerate the herbicidal activity of Throttle® XP; cold, dry conditions delay the herbicidal activity. Weeds hardened off by drought or other plant stresses are less susceptible to Throttle® XP. Moisture is needed to move Throttle® XP into the soil for preemergence weed control. Soil Activity and Degradation Chlorsulfuron - The average soil half-life is 40 days. - Chlorsulfuron is moderately mobile at high pH. Leaching is less at pH < 6. Sulfometuron - Typical field half-life is 20 - 28 days at pH 6 -7. Sulfentrazone - The average soil half-life is 242 days (at pH 5 - 9). - Mobile in soil with high sand content and low OM. - Do not use on coarse soils classified as sands, which have less than 1% organic matter. Weeds Controlled – over 135 species Bahiagrass Bluegrass Canada thistle Carrot, wild Cheatgrass Crabgrass Foxtails, except green Goldenrod Kochia Lambsquarter Marestail/horseweed Mustard species Nightshade species Nutsedge species Pigweeed Plantain, buckhorn Puncturevine Russian thistle Rye (volunteer) Ryegrass: annual, Italian Signalgrass, broadleaf Sprangletop (annual) Wheat (volunteer) Witchgrass The degree and duration of control may depend on the weed spectrum and infestation intensity, weed size at application, soil type, organic matter content, and environment conditions at and following application. Throttle™ XP Herbicide Bareground control made easier Throttle™ XP herbicide features advanced DuPont XP formulation technology, making it easier to mix and more accurate to measure. The new formulation is less dusty and re-suspends faster to minimize downtime after rain and wind delays. How to get the best results Apply Throttle™ XP at the rate of 12.5 ounces per acre as a pre-emergence or early postemergence spray before or during the rainy season, when weeds are actively germinating or growing. Throttle™ XP available in: - 3.9-pound jug - 11.72-pound jug Results For More Information To learn more about DuPont™ herbicides, contact: – Your DuPont Representative, – On the Web at vm.dupont.com Always read and follow all label directions and precautions for use. The DuPont Oval Logo, DuPont™, The miracles of science™, Landmark®, Karmex®, Krovar® and Oust® are trademarks or registered trademarks of DuPont or its affiliates. Copyright© 2006 E.I. du Pont de Nemours and Company. All Rights Reserved. 2/06