AGRICHEMICALS AND THEIR PROPERTIES
Bob Parker
Revised October 31, 2008

This information provides specifications for users of this handbook. For more information regarding the physiological or biochemical activity and behavior in or on soils, refer to the Herbicide Handbook of the Weed Science Society of America.
The acute toxicity LD50 (lethal dose to 50% of the test animals) has been stated for the formulated product when known. Refer to Managing Herbicide-resistant Weeds in this handbook for further information on Site of Action and Chemical Family to delay weed resistance to herbicides.
Caution!  This handbook is not intended as a complete guide to herbicide use. Before using any chemical, read the container’s label. A chemical must be thoroughly tested before it can be recommended for a specific use. Following the label’s recommendation can prevent many problems from arising due to wrong use of a chemical.
ACETIC ACID 
Trade name(s) WeedPharm Weed and Grass Killer 
Manufacturer(s)  Pharm Solutions
Formulation(s)  20% acetic acid
Remarks  Organic herbicide. Nonselective contact herbicide, applied undiluted to three- to five-leaf, actively growing weeds. Results are best when applied in full sunshine at temperatures above 50o F.
ACetochlor
Trade name(s)  Harness, Surpass, Cadence, TopNotch, Degree, Confidence  
Manufacturer(s)  Monsanto Co., Dow AgroSciences, Winfield
Formulation(s)  6.4 and 7 lb/gal emulsifiable concentrate; 3.2 lb/gal capsule suspension
Remarks  A selective, soil-active herbicide applied preplant or preemergence to corn.
Water solubility  223 ppm
Storage conditions  Store in a cool, dry, well-ventilated area away from sources of heat or flame.
Acute toxicity   LD50 - 2,148 mg/kg
Action in plant  Disrupts protein synthesis.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
ACIFLUORFEN
Trade name(s)  Blazer, Snapback, Ultra Blazer
Manufacturer(s)  BASF Corp, United Phosphorous
Formulation(s)  2 lb/gal water miscible concentrate
Remarks  A selective preemergence or postemergence contact herbicide for use in certain large-seed legume crops.
Water solubility  250,000 ppm
Storage conditions  Store above 32°F. Warm and shake, if frozen.
Acute toxicity   LD50 - 3,330 mg/kg
Action in plant  Acts as a selective contact that disrupts cell membrane.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
ACROLEIN (restricted-use herbicide)
Trade name(s) Magnacide H
Manufacturer(s)  Baker Petrolite
Formulation(s)  92% liquid
Remarks  A highly volatile, contact, aquatic herbicide. Use only under the supervision of licensed pesticide applicators.
Water solubility  215,000 ppm
Storage conditions  Highly reactive or forms insoluble polymers (white precipitate) in presence of oxygen. Therefore, avoid contamination with any foreign materials, especially alkaline or strong acids. Do not store opened product.
Acute toxicity   LD50 - 46 mg/kg
Action in plant  General cell toxicant that destroys enzyme systems.
Site of action  General cell toxicant
Chemical family  None generally accepted
ALACHLOR (restricted-use herbicide)
Trade name(s)  Arena, Partner, Micro-Tech, Shroud, INTRRO 
Manufacturer(s)  Monsanto Co.
Formulation(s)  4 lb/gal emulsifiable concentrate; 15% granule; 65% water-dispersible granules
Remarks  A selective, soil-active herbicide applied preplant or preemergence. Shallow, mechanical soil incorporation may be necessary to improve weed control.
Water solubility  242 ppm
Storage conditions  Store above 32°F away from heat or flame. Warm to 72°F and roll or shake frequently if frozen.
Acute toxicity   LD50 - 1,800 mg/kg
Action in plant  Inhibits roots and shoots.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
AMETRYN
Trade name(s)  Evik 
Manufacturer(s)  Syngenta
Formulation(s)  80% wettable powder
Remarks  A selective, contact herbicide with some soil residual activity. Postemergence treatments must be directed on most crops. Absorbed through foliage and roots; penetrates foliage rapidly, minimizing its removal by rain.
Water solubility  185 ppm
Storage conditions  Slight sensitivity to extreme temperatures and natural light.
Acute toxicity   LD50 - 1,750 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
AMINOPYRALID
Trade name(s)  Milestone
Manufacturer(s)  Dow AgroSciences
Formulation(s)  2 lb (ae) soluble concentrate
Remarks  A selective, foliage-applied herbicide used to control broadleaf weeds with some residual activity in the soil.
Water solubility  2,480 ppm
Storage conditions  Store above freezing; but if exposed to freezing, warm to at least 40°F and agitate well. 
Acute toxicity   LD50 - more than 5,000 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
AMMONIUM NONANOATE
Trade name(s)  Racer 
Manufacturer(s)  Falcon Lab
Formulation(s)  3.3 lb ai/gal
Remarks  Organic herbicide. Nonselective contact herbicide. A C9 saturated-chain fatty acid
ASULAM
Trade name(s)  Asulox, Asulox XP
Manufacturer(s)  United Phosphorus, Inc.
Formulation(s)  3.12 and 3.34 lb/gal soluble concentrate
Remarks  A carbamate to control actively growing grasses and certain broadleaf weeds. Effective on Johnsongrass, field horsetail, bracken fern, tansy ragwort, dock, and red sorrel.
Water solubility  20,000 ppm
Storage conditions  Store above 20°F. If frozen, warm to 70°F and agitate.
Acute toxicity   LD50 - 8,000 mg/kg
Action in plant  Inhibits mitosis.
Site of action  Group 18: inhibits DHP synthase step
Chemical family  Carbamate
ATRAZINE (most products containing atrazine are designated restricted-use)
Trade name(s)  AAtrex, Atrazine
Manufacturer(s)  Syngenta, DuPont, and others
Formulation(s)  80% wettable powder, 4 lb/gal liquid, 90% water-dispersible granule
Remarks  A selective, root-absorbed herbicide. Some foliar absorption but with little translocation. Most plant tissue contacted by spray is injured. More soluble and less strongly adsorbed on soil than simazine; thus, less moisture is needed to activate it. More active on soils with high pH.
Water solubility  33 ppm
Storage conditions  Very stable
Acute toxicity   LD50 - 5,100 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
BENEFIN
Trade name(s)  Balan
Manufacturer(s)  Loveland Products
Formulation(s)  1.5 lb/gal emulsifiable concentrate, 2.5% granule, 60% dry flowable
Remarks  A dinitroaniline compound used as preplant, soil-incorporated, selective herbicide. Requires incorporation with or immediately after application to prevent loss of activity. Residual activity at higher rates or in dry regions may be a problem on subsequent crops.
Water solubility  0.1 ppm
Storage conditions  Store above 40°F. If frozen, poor weed control may result.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits mitosis, both in shoots and in roots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
BENSULIDE
Trade name(s)  Betasan, Prefar, Betamec
Manufacturer(s)  Gowan Co., PBI/Gordon
Formulation(s)  2.9 and 4 lb/gal emulsifiable concentrate, 3.6% and 12.5% granules
Remarks  A selective compound applied preemergence. It must be applied to soil before weeds emerge.
Water solubility  25 ppm
Storage conditions  Store above 42°F depending on emulsifiable formulation. Do not store or use near heat or flame. Warm and agitate until crystals dissolve, or do not use.
Acute toxicity   LD50 - 770 mg/kg
Action in plant  Inhibits roots of seedlings.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Organophosphorus
BENTAZON
Trade name(s)  Basagran, BasagranT/O 
Manufacturer(s)  BASF, Arysta, Winfield
Formulation(s)  4 lb/gal soluble concentrate
Remarks  A selective herbicide to control many broadleaf weeds and yellow nutsedge. Rain within 24 hr after application may reduce effectiveness. Bentazon is a postemergence contact spray, so thorough coverage is essential.
Water solubility  500 ppm
Storage conditions  Store between 32° and 122°F. Warm to 70°F and agitate until crystals dissolve, or do not use.
Acute toxicity   LD50 - 1,860 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 6: photosystem II inhibitor
Chemical family  Benzothiadiazole
Bispyribac-Sodium
Trade name(s)  Velocity 
Manufacturer(s)  Valent
Formulation(s)  80% wettable powder
Remarks  For use in turf, such as golf course turfgrass and sod farms. Postemergence herbicide to control annual bluegrass, rough bluegrass, and certain broadleaf weeds in certain grasses.
Water solubility  73,000 ppm
Storage conditions  Stable under normal storage conditions.
Acute toxicity   LD50 - 2,635 mg/kg
Action in plant  Inhibits acetolactate synthase (ALS) enzyme
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Pyrimidinylthiobenzoate
BORATES, BORON
Trade name(s)  Ureabor, Monobor-Chlorate,  
Manufacturer(s)  J. R. Simplot Co., Pro-Serve
Formulation(s)  Several. Mixed with sodium chlorate and ureas.
Remarks  Nonselective broadleaf and grass weed control combinations. Borates are excellent fire retardants. Combinations are excellent for eliminating all vegetation. Some formulations are used before laying asphalt paving.
Water solubility  Quite soluble but varies with formulation.
Storage conditions  Stable.
Acute toxicity   LD50 - 2,000 to 5,560 mg/kg
Action in plant  Salt action that disrupts cell membranes.
Site of action  Unknown
Chemical family  Inorganic
BROMACIL
Trade name(s)  Hyvar X, Hyvar X-L
Manufacturer(s)  DuPont
Formulation(s)  80% wettable powder, 2 lb/gal water-soluble liquid
Remarks  A substituted uracil compound used preemergence or as a spot-treatment on brush. A nonselective soil-residual herbicide; controls a wide range of weeds and brush.
Water solubility  815 ppm
Storage conditions  Stable to 0°F, but water-soluble formulations become less soluble when exposed to air.
Acute toxicity   LD50 - 5,200 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Uracil
BROMOXYNIL
Trade name(s)  Buctril, Bromox, Moxy, Broclean, Connect Bromoxynil
Manufacturer(s)  Bayer CropScience and others
Formulation(s)  2 and 4 lb/gal emulsifiable concentrate; 20% water-soluble powder
Remarks  A selective, postemergence, contact herbicide. Controls some weeds resistant to 2,4-D. Can be safely applied to seedling grains and grasses. Has little soil activity.
Water solubility  13,000 ppm
Storage conditions  Store above 32°F. If frozen, agitate before using.
Acute toxicity   LD50 - 160 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 6: photosystem II inhibitor
Chemical family  Nitrile
BUTYLATE
Trade name(s)  Sutan, Sutan + (butylate plus safener)
Manufacturer(s)  Helm Agro
Formulation(s)  6.7 lb/gal emulsifiable concentrate
Remarks  A thiocarbamate compound used as a selective preplant-incorporated herbicide. Because of its volatility, it must be incorporated immediately after application.
Water solubility  45 ppm
Storage conditions  Stable at moderate temperatures. If frozen, roll container to mix.
Acute toxicity   LD50 - 3,878 mg/kg
Action in plant  Inhibits shoot growth. 
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
CACODYLIC ACID
Trade name(s)  Montar
Manufacturer(s)  Monterey Chemical
Formulation(s)  2.48 lb/gal soluble solution
Remarks  A postemergence, nonselective contact herbicide. Its phytotoxic properties are quickly inactivated on contact with soil.
Water solubility  667,000 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 830 mg/kg
Action in plant  Contact-type herbicide.
Site of action  Not well understood
Chemical family  Organoarsenical
CARFENTRAZONE
Trade name(s)  Aim, QuickSilver, Stingray
Manufacturer(s)  FMC Corp.
Formulation(s)  1.9 and 2 lb/gal emulsifiable concentrates
Remarks  Postemergent, contact herbicide for controlling broadleaf weeds.
Water solubility  12 ppm
Storage conditions  Stable under normal storage conditions. Store in tightly closed containers.
Acute toxicity   LD50 - 5,140 mg/kg
Action in plant  Disrupts cell membranes.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
CHLORSULFURON
Trade name(s)  Glean F.C., Telar DF
Manufacturer(s)  DuPont
Formulation(s)  75% dry flowable
Remarks  A selective preemergence or early postemergence herbicide used at low rates. Carefully consider crop rotation plans before using. Recommended for use in wheat, barley, oats, and in fallow on soils of pH 7.5 or less. Telar formulation is a selective broadleaf herbicide used preemergence to postemergence in noncropland areas.
Water solubility  587 ppm at pH 5; 31,800 ppm at pH 7
Storage conditions  Stable when excess moisture or humidity are excluded from container.
Acute toxicity   LD50 - 5,545 mg/kg
Action in plant  Interferes with enzyme acetolactate synthase, resulting in a rapid cessation of cell division and plant growth in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
CLETHODIM
Trade name(s)  Prism, Select, Envoy,  Volunteer, Arrow, Section, Trigger, SelectMax, Shadow, Intensity 
Manufacturer(s)  Valent, Tenkoz, Albaugh, Arysta, Winfield, Loveland
Formulation(s)  0.94, 0.97 and 2 lb/gal emulsifiable concentrate
Remarks  A selective postemergence grass-control herbicide. Controls most annual and perennial grasses except fine fescues. Using a crop oil concentrate enhances activity.
Storage conditions  Stable
Acute toxicity   LD50 - 2,920 mg/kg
Action in plant  Inhibits growing points in grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
CLOdinafop
Trade name(s)  Discover, Discover NG   
Manufacturer(s)  Syngenta
Formulation(s)  0.5 and 2 lb/gal emulsifiable concentrate
Remarks  Controls annual grasses postemergence.
Water solubility  4,000 ppm
Storage conditions  Store in a cool, dry place.
Acute toxicity   LD50 - 1,829 mg/kg
Action in plant  Inhibits growing points in grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
CLOMAZONE
Trade name(s)  Command
Manufacturer(s)  FMC Corp.
Formulation(s)  3 lb/gal encapsulated herbicide
Remarks  A selective, preplant-incorporated herbicide; controls several annual weeds. Some foliar activity. Offsite movement can whiten or yellow plant foliage.
Water solubility  1,100 ppm
Storage conditions  Store above 40°F. If frozen, warm to 60°F and shake or roll container.
Acute toxicity   LD50 - 1,369 mg/kg
Action in plant  Inhibits synthesis of photosynthetic pigments, both chlorophyll and carotenoids.
Site of action  Group 13: inhibits DOXP synthase
Chemical family  Isoxazolidone
CLOPYRALID
Trade name(s)  Stinger,Transline, Clopyr Ag
Manufacturer(s)  Dow AgroSciences
Formulation(s)  3 lb/gal soluble concentrate
Remarks  A highly translocated, selective herbicide active primarily through foliage of broadleaf herbaceous weeds (mostly the Asteraceae, Fabaceae, and Polygonaceae families). Curtail is clopyralid + 2,4-D; Redeem R&P and Confront are clopyralid + triclopyr.
Water solubility  1,000 ppm
Storage conditions  Store above 28°F or warm to 40°F and agitate before use.
Acute toxicity   LD50 - 4,300 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
CLOVE LEAF OIL
Trade name(s)  Matran EC 
Manufacturer(s)  EcoSmart
Formulation(s)  50% emulsifiable concentrate 
Remarks  Organic herbicide. Nonselective contact herbicide. 
COPPER SULFATE
Trade name(s)  Copper Sulfate, Blue Stone
Manufacturer(s)  Chem One Limited, Griffin, Phelps Dodge, Nufarm
Formulation(s)  25% crystals; also available impregnated in clay and as liquid.
Remarks  Used primarily to control algae in impounded waters, lakes, ponds, reservoirs, and irrigation systems.
Water solubility  Very soluble
Storage conditions  Stable when kept dry.
Acute toxicity   LD50 - 470 mg/kg
Action in plant  Causes imbalance of copper with other enzyme metal cofactors, resulting in enzyme blockage.
Site of action  Plant cells
Chemical family  Inorganic
CORN OR MAIZE GLUTEN MEAL
Trade name(s)  WOW, A-Maize-N
Manufacturer(s)  Gardens Alive!, Wilbur-Ellis
Formulation(s)  100% dry
Remarks  Organic herbicide, is a by-product of the wet milling process of making cornstarch or corn syrup.
CYCLOATE
Trade name(s)  Ro-Neet
Manufacturer(s)  Helm Agro
Formulation(s)  6 lb/gal emulsifiable concentrate, 10% granules
Remarks  A selective, thiocarbamate herbicide applied preplant and soil incorporated. For best results, incorporate immediately into the top 2 to 3 inches of soil. Cycloate is absorbed by seed and stem tissue of seedlings.
Water solubility  85 ppm
Storage conditions  Store above 20°F but away from sources of heat and flame. Warm and agitate.
Acute toxicity   LD50 - 3,160 mg/kg
Action in plant  Inhibits shoot growth.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
D-LIMONENE
Trade name(s)  GreenMatch O, Nature’s Avenger
Manufacturer(s)  Cutting Edge Formulations and Marrone Organic Innovations
Formulation(s)  17.5 and 70% EC
Remarks  OMRI-listed for organic production. D-limonene is a citrus extract. Nonselective contact herbicide
DAZOMET
Trade name(s)  Mylone
Manufacturer(s)  Hopkins Agricultural Chemical Co.
Formulation(s)  50% dust, 99% granule
Remarks  Soil fumigant used in seedbed preparation to control weeds, nematodes, soil fungi, and certain insects. Preplant incorporate using conventional equipment. Adequate soil moisture is important for its biological activity. In soil, dazomet presumably is converted to formaldehyde, hydrogen sulfide, and methyl isothiocyanate.
Water solubility  2,000 ppm
Storage conditions  Store at 32° to 102°F. Keep dry.
Acute toxicity   LD50 - 320 mg/kg
Action in plant  Attacks cell membranes.
Site of action  Not well understood
Chemical family  Dithiocarbamate
DCPA
Trade name(s)  Dacthal, Garden Weed Preventer
Manufacturer(s)  AMVAC
Formulation(s)  75% wettable powder, 25% and 5% granule, 6 lb flowable
Remarks  A soil-active, preemergence, selective herbicide. Must be applied to soil before weed seeds germinate. Moisture needed to activate. Not foliage active.
Water solubility  0.5 ppm
Storage conditions  Stable when kept dry.
Acute toxicity   LD50 - greater than 3,000 mg/kg
Action in plant  Inhibits mitosis in roots and shoots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Phthalic acid
DESMEDIPHAM
Trade name(s)  Betanex, Alphanex
Manufacturer(s)  Bayer CropScience, United Phosphorus, Inc.
Formulation(s)  1.3 lb/gal emulsifiable concentrate
Remarks  A foliar-applied, selective herbicide for weeds in sugarbeets. Rain within 6 hours of spraying may reduce weed kill. Do not apply to sugarbeets within 90 days before harvest.
Water solubility  7 ppm
Storage conditions  Store above 15°F. If frozen, warm and mix at 50°F. Avoid use or storage near heat or flame.
Acute toxicity   LD50 - 3,700 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Phenylcarbamate
DICAMBA
Trade name(s)  Banvel, Banvel II, Banvel SGF, Clarity, Vanquish, Dicamba, Rifle
Manufacturer(s)  BASF, Syngenta, Arysta
Formulation(s) 1, 2, and 4 lb/gal water- and oil-soluble concentrates, 10% granules
Remarks  A growth-regulating herbicide readily absorbed and translocated from either roots or foliage. Effects similar to those of 2,4-D.
Water solubility  4,500 ppm
Storage conditions  Store above 15°F.
Acute toxicity   LD50 - 1,028 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Benzoic acid
DICHLOBENIL
Trade name(s)  Casoron, Barrier
Manufacturer(s)  Chemtura, PBI/Gordon
Formulation(s)  50% wettable powder, 4% granules, 15.3% liquid
Remarks  A nitrile compound used as a preemergent and early postemergent herbicide in noncrop areas and around established trees and shrubs. Dichlobenil is most effective when applied before weeds emerge, during cool weather, and immediately incorporated through irrigation or rain. It has little, if any, effect on foliage.
Water solubility  25 ppm
Storage conditions  Store under cool, dry conditions to avoid volatility.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits meristematic tissue in growing points of roots and shoots.
Site of action  Group 20: inhibits cell wall synthesis Site A
Chemical family  Nitrile
DICHLORPROP, 2,4-DP
Trade name(s)  Weedone 2,4-DP
Manufacturer(s)  PBI/Gordon, Riverdale, Monterey
Formulation(s)  4 lb/gal emulsifiable concentrate
Remarks  A translocated, postemergence herbicide effective against certain broadleaf weeds and brush species.
Water solubility  710 ppm
Storage conditions  Read each product label.
Acute toxicity   LD50 - 800 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
DICLOFOP (restricted-use herbicide)
Trade name(s)  Hoelon
Manufacturer(s)   Bayer CropScience
Formulation(s)  3 lb/gal emulsifiable concentrate
Remarks  A selective herbicide applied postemergence. Controls several grass species; has some residual activity. Antagonistic response if mixed with phenoxy herbicides.
Water solubility  3,000 ppm
Storage conditions  Store above 20°F. If frozen, warm and agitate.
Acute toxicity   LD50 - 580 mg/kg
Action in plant  Inhibits growing points in grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
DIFENZOQUAT
Trade name(s)  Avenge
Manufacturer(s)  Amvac
Formulation(s)  2 lb/gal water miscible concentrate
Remarks  A selective herbicide to control wild oat. Rain within 6 hours after application reduces effectiveness.
Water solubility  765,000 ppm
Storage conditions  Store above 32°F. Ice will form at 15°F; remix at warmer temperatures before use.
Acute toxicity   LD50 - 730 mg/kg
Action in plant  Action unknown.
Site of action  Group 26: unknown
Chemical family   Pyrazolium
DIFLUFENZOPYR
Trade name(s)  Mixed with dicamba and sold as Distinct and Overdrive
Manufacturer(s)  BASF
Formulation(s)  70% dry flowable with dicamba
Remarks  Postemergence, translocated herbicide to control broadleaf weeds.
Water solubility  270 ppm at pH 5; 5,850 ppm at pH 7
Storage conditions  Cool, dry conditions.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits auxin transport.
Site of action  Group 19: inhibits indole acetic acid transport
Chemical family  Semicarbazone
DIMETHENAMID, DIMETHENAMID-P
Trade name(s)  Frontier, Outlook
Manufacturer(s)  BASF
Formulation(s) 6 and 7.5 lb/gal emulsifiable concentrate
Remarks  A chloroacetamide compound used as a selective, preemergence herbicide, particularly for grass control in field corn. Also controls several broadleaf weeds. Dimethenamid-P is the more active isomer of dimethenamid and is used at lower rates.
Water solubility  1,174 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 2,400 mg/kg
Action in plant  Inhibits plant cell division and growth.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family   Chloroacetamide
DIQUAT (a moderately toxic herbicide that requires protective gear for handling and application)
Trade name(s)  Diquat Herbicide, Reward, Reglone
Manufacturer(s)  Syngenta
Formulation(s)  2 lb water-soluble cation/gal (3.73 lb/gal salt). Cation portion of the molecule is the active ingredient.
Remarks  A fast-acting, nonselective, foliar-applied, contact herbicide and plant desiccant. Material is slightly translocated. It is completely inactivated on contact with soil. Using a surfactant enhances its activity.
Water solubility  700,000 ppm
Storage conditions  Store above 32°F.
Acute toxicity   LD50 - 125 mg/kg for mouse.
Action in plant  Acts as contact. Absorbs energy produced by photosynthesis; forms peroxides that disrupt living cells.
Site of action  Group 22: photosystem I electron diversion
Chemical family  Bipyridilium
DITHIOPYR
Trade name(s)  Dimension EC, Dimension EW, Dimension Ultra 40 WP, Lifeguard  
Manufacturer(s)  Dow AgroSciences
Formulation(s)  1 and 2 lb/gal emulsifiable concentrate and 40% wettable powder
Remarks  Selective control of many annual grasses and certain annual broadleaf weeds in established cool- and warm-season turfgrasses in lawns and ornamental turf.
Water solubility  0.7 ppm
Storage conditions  Store above 32°F.
Acute toxicity   LD50 - more than 5,000 mg/kg
Action in plant  Interferes with cell division.
Site of action  Group 3: microtubule assembly inhibitor  
Chemical family  Pyridine
DIURON
Trade name(s)  Karmex, Diuron, Direx
Manufacturer(s)  DuPont, Griffin Corp., Platte Chemical Co., Dow AgroSciences
Formulation(s)  80% wettable powder, 80% dry flowable, 4 lb/gal water dispersible liquid
Remarks  A substituted urea compound used preemergence to control annual weeds and certain perennials in noncropland and certain agricultural crops. Plant roots absorb and translocate material. It is foliar absorbed when used with a wetting agent. Diuron may persist several months in soil.
Water solubility  42 ppm
Storage conditions  Stable at moderate temperatures.
Acute toxicity   LD50 - 3,400 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
DSMA
Trade name(s)  DSMA Liquid, Weed-E-Rad
Manufacturer(s)  Drexel Chemical Co., Monterey
Formulation(s)  64% soluble powder (100% hexahydrate), 3.6 and 7.2 lb/gal soluble concentrate
Remarks  An organic, arsenical compound used as a selective contact herbicide applied postemergence. DSMA takes up moisture, so store in a dry place. Use a surfactant to ensure activity.
Water solubility  Very soluble
Storage conditions  Stable under moderate conditions.
Acute toxicity   LD50 - 3,630 mg/kg
Action in plant  Unknown 
Site of action  Group 17: not well understood
Chemical family   Organoarsenical
ENDOTHALL (restricted-use herbicide)
Trade name(s)  Aquathol, Aquathol K, Hydrothol 191, Des-l-Cate, Accelerate
Manufacturer(s)  United Phosphorus, Inc.
Formulation(s)  0.52, 2, and 3 lb/gal soluble concentrates and 7.2 to 44.7% granules, formulated as dipotassium salt and as a number of amine salts.
Remarks  Used in sugar beets and turf, as an aquatic herbicide, and as a preharvest desiccant. Irritates skin and eyes. In water it generally breaks down within 10 days.
Water solubility  100,000 ppm
Storage conditions  Store above 32°F. If frozen, warm and agitate.
Acute toxicity  LD50 - 182 mg/kg
Action in plant  Specific action unknown; disrupts cell membranes.
Site of action  Not well understood
Chemical family  None generally recognized
EPTC
Trade name(s)  Eptam, Eradicane (EPTC plus safener)  
Manufacturer(s)  Gowan
Formulation(s)  6, 6.7, and 7 lb/gal emulsifiable concentrates,10% granule
Remarks  A selective, thiocarbamate herbicide applied preplant and soil incorporated. Must be incorporated immediately after application due to volatility. EPTC is absorbed by the shoots of emerging weed seedlings. Eradicane is used for corn.
Water solubility  370 ppm
Storage conditions  Store above -50°F and below moderately warm temperatures. If frozen, roll container to mix.
Acute toxicity   LD50 - 1,652 mg/kg
Action in plant  Inhibits shoot growth.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
ETHALFLURALIN 
Trade name(s)  Sonalan, Curbit
Manufacturer(s)  Dow AgroSciences, Loveland Products
Formulation(s)  3 lb/gal emulsifiable concentrate
Remarks  A selective, preemergence herbicide that should be soil incorporated. Do not incorporate when using on cucurbits. Ethalfluralin has little or no foliar activity.
Water solubility  0.3 ppm
Storage conditions  Store above 40°F.
Acute toxicity   LD50 - greater than 10,000 mg/kg
Action in plant  Inhibits mitosis in shoots and roots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
ETHAMETSULFURON
Trade name(s)  Muster 
Manufacturer(s)  DuPont
Formulation(s) 75% water soluble granule
Remarks  Effective in controlling selected broadleaf weeds.
Water solubility  1.7 ppm at pH 5, 50 ppm at pH 7, 410 ppm at pH 9
Acute toxicity   LD50 - greater than 5,000 mg/kg 
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
ETHOFUMESATE
Trade name(s)  Nortron, Prograss, Ethotron, Poa Constrictor 
Manufacturer(s)  Bayer CropScience, United Phosphorus 
Formulation(s)  1.5 and 4 lb/gal emulsifiable concentrate
Remarks  A selective herbicide for weed control in sugar beets and several grass seed crops.
Water solubility  110 ppm
Storage conditions  Store above 34°F.
Acute toxicity   LD50 - 6,400 mg/kg
Action in plant  Unknown
Site of action  Group 16: unknown
Chemical family   Benzofuran
FENOXAPROP
Trade name(s)  Acclaim, Puma
Manufacturer(s)  Bayer CropScience
Formulation(s)  1 lb/gal emulsifiable concentrate
Remarks  Selective postemergence grass control herbicides effective in some grass seeds, turfgrass, rice, and soybeans.
Water solubility  0.9 ppm
Storage conditions  Store between 10° and 100°F. Avoid using or storing near heat or flame.
Acute toxicity   LD50 - 2,357 mg/kg
Action in plant  Inhibits growing point in grasses. 
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
Florasulam
Trade name(s)  Ingredient in Orion and GoldSky
Manufacturer(s)  Dow, Syngenta
Formulation(s)  Packaged with other herbicides.
Remarks  Broadleaf herbicide used in cereals for broadleaf weed control.
Water solubility  84 ppm at pH 5, 6360 ppm at pH 7, and 94,200 ppm at pH 9
Storage conditions  Not available
Acute toxicity  LD50 - greater than 6000 mg/kg
Action in plant  Inhibits acetolactate synthase (ALS) enzyme
Site of action  Group 2: acetolactate synthase inhibitor
Chemical family  Sulfonanalide
FLUAZIFOP
Trade name(s) Fusilade DX
Manufacturer(s)  Syngenta
Formulation(s)  2 lb/gal emulsifiable concentrate
Remarks  A selective, postemergence grass herbicide to control most annual and perennial grasses except annual bluegrass and all fine fescues. A nonionic surfactant or crop oil concentrate enhances activity.
Water solubility  1.1 ppm
Storage conditions  Store at moderate temperatures.
Acute toxicity   LD50 - 4,350 mg/kg
Action in plant  Inhibits growing points in grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
FLUCARBAZONE
Trade name(s)  Everest, Pre-Pare  
Manufacturer(s)   Arysta
Formulation(s)  70% water-dispersible granule (66% acid equivalent)
Remarks  Low-rate herbicide applied postemergence to control grasses in wheat. Has some activity on broadleaf weeds.
Water solubility  44,000 ppm
Storage conditions  Store in cool, dry conditions.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylaminocarbonyltriazolinone
FLUFENACET
Trade name(s)  Define  
Manufacturer(s)   Bayer CropScience
Formulation(s)  60% dry flowable, 4 lb/gal soluble concentrate
Remarks   Effective on several annual grasses and some small-seed broadleaf weeds.
Water solubility  56 ppm
Storage conditions  Store in a cool dry place. Storage above 100°F results in loss of active ingredient.
Acute toxicity   LD50 - 371 mg/kg 
Action in plant  Interferes with meristematic activity.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family   Oxyacetamide
FLUmetsulam
Trade name(s)  Python  
Manufacturer(s)   Dow AgroSciences
Formulation(s)  80% water-dispersible granule
Remarks  Herbicide applied preplant, preemergence, or early postemergence to control broadleaf weeds in field corn. Flumetsulam is package-mixed with several products and marketed under various trade names.
Water solubility  49 ppm at pH 2.5; 5,600 ppm at pH 7
Storage conditions  Stable under normal storage conditions.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Triazolopyrimidine
FLUMICLORAC
Trade name(s)  Resource
Manufacturer(s)   Valent USA Corp
Formulation(s)  0.86 lb/gal emulsifiable concentrate
Remarks  Contact postemergence herbicide for controlling certain annual broadleaf weeds in field corn and soybeans.
Water solubility  0.189 ppm
Storage conditions  Stable under normal storage conditions.
Acute toxicity   LD50 - 3,600 mg/kg
Action in plant  Acts as a contact-type herbicide.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  N-phenylphthalimide
FLUMIOXAZIN
Trade name(s)  Valor, Chateau, SureGuard, Payload, BroadStar 
Manufacturer(s)  Valent
Formulation(s)  51% water-dispersible granule, 0.25% granular
Remarks  A preemergence and postemergence herbicide for controlling some broadleaf weeds. Has some residual effect when used preemergence. Rapidly burns down broadleaf weeds when used postemergence.
Water solubility  1.78 ppm
Storage conditions  Stable under normal storage conditions.
Acute toxicity   LD50 - greater than 5,000 ppm
Action in plant  Inhibits protoporphyrinogen oxidase, an enzyme important in the synthesis of chlorophyll; acts as a contact herbicide.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  N-phenylphthalimide
FLURIDONE
Trade name(s) Sonar, SonarOne, Avast! 
Manufacturer(s)  SePRO
Formulation(s)  4 lb/gal flowable, 5% slow-release pellets
Remarks  An aquatic herbicide to control submersed and immersed plants. Not particularly effective in controlling floating aquatic plants.
Water solubility  12 ppm
Storage conditions  Store at moderate temperatures, although no adverse effects have been observed after freezing.
Acute toxicity   LD50 - greater than 10,000 mg/kg
Action in plant  Inhibits carotene formation, resulting in chlorophyll destruction.
Site of action  Group 12: bleaching; inhibits carotenoid biosynthesis
Chemical family  None generally recognized
fluroxypyr
Trade name(s) Vista, Vista XRT, Starane, Starane Ultra, Spotlight
Manufacturer(s)   Dow AgroSciences, Loveland Products
Formulation(s)  1.5 and 2.8 lb/gal emulsifiable concentrate
Remarks  A growth-regulating, foliage-applied herbicide to control broadleaf plants. Effects are similar to those of 2,4-D.
Water solubility  0.11 ppm
Storage conditions  Store above 10°F.
Acute toxicity   LD50 - greater than 2,000 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
FLUTHIACET
Trade name(s)  Cadet
Manufacturer(s)  FMC
Formulation(s) 0.91 lb/gal EC
Remarks  Cadet is a postemergence herbicide for broadleaf weed control in corn and soybeans in Idaho only.
Water solubility  0.85 ppm
Storage conditions  Store in a cool dry place and avoid excess heat. Do not store below 32°F.
Acute toxicity  LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits protoporphyrinogen oxidase (PPO) that disrupts cell membranes
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Triazinone
FORAMSULFURON
Trade name(s)  Option
Manufacturer(s)  Bayer CropScience
Formulation(s)  35% water-dispersible granule
Remarks  Selective postemergence herbicide to control grasses and some small-seed broadleaf weeds in corn.
Water solubility  3,290 ppm at 68°F (20°C) and pH 7
Storage conditions  Stable storage.
Acute toxicity   LD50 - greater than 3,881 mg/kg
Action in plant  Interferes with acetolactate synthase enzyme, resulting in a rapid cessation of cell division and plant growth in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
FOSAMINE
Trade name(s)  Krenite S
Manufacturer(s)  DuPont
Formulation(s)  4 lb/gal soluble concentrate
Remarks  A brush-control herbicide applied during the 2 mo before fall coloration.
Water solubility  1,790,000 ppm
Storage conditions  Stable as formulated or as spray-tank solution.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits bud and new leaf formation in spring.
Site of action  Group 26: unknown
Chemical family  Organophosphorus
GLUFOSINATE
Trade name(s)  Finale, Ignite, Ignite 280SL, Rely, Liberty, Derringer 
Manufacturer(s)  Bayer CropScience
Formulation(s)  1 lb, 1.67, and 2.34 lb/gal aqueous solutions
Remarks  A nonselective, postemergent, contact herbicide with some systemic activity. Acts faster than glyphosate but more slowly than paraquat. More active on broadleaf weeds than on grasses.
Water solubility  1,370,000 ppm
Storage conditions  Stable under normal storage conditions. Do not store near heat or open flame.
Acute toxicity   LD50 - 1,620 mg/kg
Action in plant  Causes ammonium ions to accumulate, disrupting photosynthesis.
Site of action  Group 10: glutamine synthase inhibitor
Chemical family  Phosphinic acid
GLYPHOSATE
Trade name(s)  Roundup, Rodeo, Kleenup, Accord, Honcho, E-Z-Ject, Jury, Mirage, Protocol, Rattler, Ruler, Silhouette, Glypro, Glyphomax, AquaNeat, Touchdown, Glyphosate, Durango, RT Master, and many others 
Manufacturer(s)  Monsanto Co., Dow AgroSciences, Syngenta, DuPont, and others
Formulation(s)  1.23, 2, 3, 3.7, 4, 4.17, 4.75, and 5 lb/gal acid equivalent; 64.9% and 85% acid equivalent soluble powder.
Remarks  A nonselective translocated herbicide with no apparent soil activity. Rain within 6 hours after application may reduce effectiveness. Glyphosate translocates to roots and rhizomes of perennial weeds. Complete control may require retreatment. Low-volume applications are most effective.
Water solubility  12,000 ppm
Storage conditions  Store between -20° and 120°F.
Acute toxicity   LD50 - 5,400 mg/kg
Action in plant  Inhibits three amino acids and protein synthesis.
Site of action   Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
HALOSULFURON
Trade name(s)  Sandea
Manufacturer(s)  Nissan Chemical Industries, labeled by Gowan
Formulation(s)  15% and 75% water-soluble granule
Remarks  A selective herbicide for controlling broadleaf weeds and yellow nutsedge in several crops
Water solubility  15 ppm at pH 5; 1,630 ppm at pH 7.
Storage conditions  Stable when excess moisture or humidity are excluded from container.
Acute toxicity   LD50 - 8,860 mg/kg
Action in plant  Interferes with acetolactate synthase enzyme, resulting in a rapid cessation of cell division and plant growth in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
HEXAZINONE
Trade name(s)  Velpar, Velpar DF, Velpar L, Velpar ULW, Pronone
Manufacturer(s)  DuPont
Formulation(s)  90% soluble powder, 2 lb/gal miscible liquid, 75% granule, 10% granule
Remarks  A foliar- or soil-applied herbicide with soil activity for broadleaf weed, brush, and grass control in cropland, noncropland, forest lands, and rangeland.
Water solubility  33,000 ppm
Storage conditions  Store above 32°F.
Acute toxicity   LD50 - 860 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazinone 
IMAZAMETHABENZ
Trade name(s)  Assert
Manufacturer(s)  Nufarm
Formulation(s)   2.5 lb/gal liquid concentrate
Remarks  A selective, postemergence herbicide for wild oat and some weeds. Readily absorbed through roots and foliage. Assert is a mixture of two positioned isomers.
Water solubility  1,370 ppm m-isomer, 857 ppm p-isomer
Storage conditions  Stable at least 33 months at 75°F.
Acute toxicity   LD50 - 2,679 mg/kg
Action in plant  Disrupts protein and DNA synthesis.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
IMAZAMOX
Trade name(s)  Raptor, Beyond, Clearcast 
Manufacturer(s)  BASF
Formulation(s)   1 lb/gal emulsifiable concentrate
Remarks  An adjuvant and fertilizer are required for maximum weed control. Activity similar to imazethapyr, with shorter soil residual.
Water solubility  Miscible
Storage conditions  Do not store below 32°F.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
IMAZAPIC
Trade name(s)  Plateau, Oasis
Manufacturer(s)  BASF
Formulation(s)   70% dispersible granule and 2 lb/gal soluble concentrate
Remarks  Manufacturer has elected to sell Plateau only to government agencies and not to farmers or ranchers. A selective postemergence herbicide effective for controlling broadleaf weeds and some grasses.
Water solubility  2,200 ppm
Storage conditions  Store liquid formulation above 20°F.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
IMAZAPYR
Trade name(s)  Arsenal, Chopper, Contain, Arsenal Applicator Concentrate, Stalker, Habitat, Imazapyr E-Pro 4, Polaris 
Manufacturer(s)  BASF
Formulation(s)   Aqueous solutions of 2, 1, and 4 lb/gal without a surfactant
Remarks  Nonselective, imidazolinone herbicide applied preemergence or postemergence for long-term total vegetation control. Readily absorbed through foliage and roots. Registered for use only on noncropland.
Water solubility  15,000 ppm
Storage conditions  Store above 10°F. Once mixed, solution can be stored in spray tank until ready to be applied.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits enzyme used in synthesis of some amino acids.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
IMAZAQUIN
Trade name(s)  Scepter
Manufacturer(s)  BASF
Formulation(s)    70% dispersible granule
Remarks  A selective preplant-incorporated, preemergence or postemergence herbicide effective in controlling broadleaf weeds and some grasses. A nonionic surfactant or oil adjuvant improves efficacy of postemergence treatments.
Water solubility  60 ppm
Storage conditions  Stable in normal storage conditions.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
IMAZETHAPYR
Trade name(s)  Pursuit
Manufacturer(s)  BASF
Formulation(s)   Aqueous solutions of 2 lb/gal, 70% dispersible granules
Remarks  A selective postemergence herbicide effective in controlling broadleaf weeds and some annual grasses.
Water solubility  Miscible.
Storage conditions  Do not store below 32°F. 
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Imidazolinone
Iodosulfuron
Trade name(s)  Autumn
Manufacturer(s)  Bayer CropScience
Formulation(s)   10% water-dispersible granule 
Remarks  Burn down weeds prior to planting corn.
Water solubility  160, 250, and 65,000 ppm at pH 5, 7, and 9 respectively.
Storage conditions  Stable.
Acute toxicity   LD50 - 2,678 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
ISOXABEN
Trade name(s)  Gallery
Manufacturer(s)  Dow AgroSciences
Formulation(s)   75% dry flowable
Remarks  A selective preemergence herbicide applied before weed seed germinates. For annual broadleaf weeds in turf and ornamentals.
Water solubility  1 ppm
Storage conditions  Stable under moderate conditions. Avoid temperatures above 120°F.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Appears to disrupt root and hypocotyl development. Susceptible plants die before emerging.
Site of action  Group 21: inhibits cell wall synthesis Site B
Chemical family  Benzamide
LactofEN
Trade name(s)  Cobra , Phoenix
Manufacturer(s)  Valent
Formulation(s)   2 lb/gal emulsifiable concentrate
Remarks  A selective, contact herbicide with some preemergence activity. Most active on broadleaf plants.
Water solubility  0.1 ppm
Storage conditions  Will not freeze down to 0°F. Negligible decomposition in 2-yr stability tests.
Acute toxicity   LD50 - 2,533 mg/kg
Action in plant  Thought to result from the generation of toxic oxygen species in the presence of light, resulting in desiccation from peroxidation of membrane lipids.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
LEMONGRASS OIL
Trade name(s)  GreenMatch EX
Manufacturer(s)  Marrone Organic
Formulation(s)  50% emulsifiable concentrate
Remarks  Organic herbicide. Nonselective contact herbicide.
LINURON
Trade name(s)  Lorox, Linex
Manufacturer(s)  DuPont, Drexel, Griffin Corp.
Formulation(s)   50% wettable powder, 50% dry flowable, 4 lb/gal flowable suspension
Remarks  A substituted urea applied pre- and postemergence as a selective herbicide; foliar- and root-absorbed. Soil residual life shorter than other urea herbicides.
Water solubility  75 ppm
Storage conditions  Stable under moderate conditions.
Acute toxicity   LD50 - 1,500 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
MCPA
Trade name(s)  several
Manufacturer(s)  Albaugh, Loveland Products
Formulation(s)   2 and 4 lb/gal soluble and emulsifiable concentrates formulated as amine salts, sodium salts, and esters.
Remarks  A postemergence, selective, translocated phenoxy herbicide. Material is less phytotoxic to some crops.
Water solubility  825 ppm
Storage conditions  Amine formulations are relatively stable, but esters depend on emulsifying system. Read each product label carefully.
Acute toxicity   LD50 - 800 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
MCPB
Trade name(s)  Thistrol, Can-Trol
Manufacturer(s)  Nufarm
Formulation(s)   2 lb/gal soluble concentrate
Remarks  A phenoxy compound used as a selective herbicide applied postemergence. Material is beta-oxidized to MCPA by susceptible plants.
Water solubility  44 ppm
Storage conditions  Store above 32°F. If frozen, warm for several days and mix.
Acute toxicity   LD50 - 700 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
MECOPROP, MCPP
Trade name(s)  Mecopar, Mecopex Turf Herbicide, MCPP, Mecomec 4
Manufacturer(s)  PBI/Gordon
Formulation(s)  2, 2.5, and 4 lb/gal soluble concentrates, available as amine and potassium salts
Remarks  A phenoxy compound used as a selective herbicide applied postemergence. Safer on bentgrass lawns and greens than other phenoxy compounds.
Water solubility  620 ppm
Storage conditions  Stable at moderate temperatures and redissolves, if frozen.
Acute toxicity   LD50 - 650 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
MESOSULFURON
Trade name(s)  Osprey 
Manufacturer(s)  Bayer
Formulation(s)  4.5% water-dispersible granule
Remarks  Postemergence herbicide used primarily to control annual grasses and some broadleaf weeds in winter wheat.
Water solubility  7 ppm at pH 5; 48 at pH 7
Storage conditions  Protect from extreme heat and cold
Acute toxicity   LD50 - greater than 5,000 mg/kg 
Action in plant  Inhibits the acetolactate synthase (ALS) enzyme, resulting in rapid cessation of cell division and plant growth in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
MEsotrione
Trade name(s)   Callisto 
Manufacturer(s)  Syngenta
Formulation(s)  4 lb/gal suspension concentrate
Remarks  Mesotrione is a synthetic relative of natural herbicides produced by the plant Callistemon citrinus. Controls broadleaf weeds in corn.
Water solubility  15,000 ppm
Storage conditions  Can be stored as low as 20°F.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits HPPD enzymes essential to photosynthesis.
Site of action  Group 28: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family  Triketone
METHAM
Trade name(s)  Vapam, Soil-Prep, Soil Clean-Up
Manufacturer(s)  AMVAC, NovaSource
Formulation(s)  Soluble concentrate
Remarks  Temporary soil fumigant as a preplant treatment. Controls weeds, most weed seeds, certain microorganisms, and nematodes. Activity depends on decomposition in moist soil to a volatile toxicant.
Water solubility  722,000 ppm
Storage conditions  Store above 0°F to avoid crystallizing.
Acute toxicity   LD50 - 285 mg/kg
Action in plant  Kills living tissue.
Site of action  Group 26: unknown 
Chemical family  Dithiocarbamate
METHYL BROMIDE (restricted-use herbicide)
Trade name(s)  Dowfume MC-2, Pestmaster, Soil Fumigant-1, Meth-O-Gas
Manufacturer(s)  Dow AgroSciences, Great Lakes Chemical Co.
Formulation(s)  Liquid under pressure, methyl bromide 98%, chloropicrin 2% (to give offensive odor).
Remarks  Temporary soil fumigant as a preplant treatment. Controls weeds, most weed seeds, certain microorganisms, and nematodes. Applied on plant beds under a gas-proof cover. Acts within 48 hours. Use extreme caution in handling this material.
Water solubility  530 ppm
Storage conditions  Store away from heat or flame since contents are pressurized.
Acute toxicity   LD50 - 1 mg/kg with upper safe limit at 17 ppm in air.
Action in plant  Kills living tissue.
Site of action   Unknown
Chemical family  Halogenated aliphatic
METOLACHLOR,  S-METOLACHLOR
Trade name(s)   Dual, Dual Magnum, Dual II Magnum, Pennant, Me-Too-Lachlor, Brawl, Parallel, Charge Max
Manufacturer(s)  Syngenta, Makhteshim Agan of North America
Formulation(s)  7.62, 7.64, 7.8, and 8 lb/gal emulsifiable concentrate, 5% granule
Remarks  Acetamide compound; a selective, preemergence herbicide primarily for annual grass and yellow nutsedge. Usually combined with materials that kill annual broadleaf weeds. S-metolachlor is the more active isomer, used at lower rates on the same crops; other characteristics are the same.
Water solubility  530 ppm
Storage conditions  Store above -30°F.
Acute toxicity   LD50 - 2,534 mg/kg
Action in plant  Inhibits roots and shoots. 
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family   Chloroacetamide
METRIBUZIN
Trade name(s)   Sencor, TriCor 
Manufacturer(s)  Bayer CropScience, United Phosphorus, Inc. 
Formulation(s)  4 lb/gal flowable liquid; 75% dry flowable
Remarks  A selective preemergence and postemergence herbicide to control grass and broadleaf weeds.
Water solubility  1,220 ppm
Storage conditions  Stable if kept dry and stored under moderate temperatures to 15°F.
Acute toxicity   LD50 - 4,000 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazinone 
METSULFURON
Trade name(s)  Escort, Ally, Metsulfuron, and several others
Manufacturer(s)  DuPont
Formulation(s)  60% dry flowable
Remarks  A selective postemergence herbicide used at low rates to control broadleaf weeds in wheat, barley, and fallow. Escort is used for selective broadleaf weed and brush control in pastures, rangeland, and noncropland.
Water solubility  270 ppm at pH 4.6; 9,500 ppm at pH 6.7
Storage conditions  Stable if kept dry.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with an enzyme, resulting in rapid cessation of cell division in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
MH, MALEIC HYDRAZIDE
Trade name(s)   MH-30, Sprout Stop, Retard
Manufacturer(s)  Chemtura, Drexel Chemical 
Formulation(s)  1.5 lb, 2.25 lb, and 3 lb/gal soluble concentrate; 60% granule
Remarks  A growth inhibitor and preemergence or postemergence selective herbicide. Inhibits cell division but not cell enlargement. Suppresses growth of grasses and some broadleaf plants. Absorption rate is greater in high humidity.
Water solubility  6,000 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 3,900 mg/kg
Action in plant  Inhibits mitosis.
Site of action  Not well understood
Chemical family  None generally accepted
MONOCARBAMIDE  DIHYDROGENSULFATE
Trade name(s)   Superquik 
Manufacturer(s)  Entek Corp.
Formulation(s)  79% per gal liquid.
Remarks  Corrodes nylon, aluminum, and any copper alloy such as brass. Do not use pumps or fittings containing nylon, mild steel, aluminum, brass, leather, or natural rubber. Non-nylon plastic and 316-L stainless steel are recommended for application equipment.
Water solubility  Very soluble
Storage conditions  Store between 32° and 176°F.
Hazards  Corrosive to eyes and skin. Superquik can attack cotton, nylon, and leather clothing. Do not mix with nitrogen fertilizer; mixtures may explode.
Action in plant  Contact and disrupts all membranes.
Site of action  Plant cells
Chemical family  Inorganic
MSMA
Trade name(s)  Arsonate, Daconate, Trans-Vert, Bueno
Manufacturer(s)  Platte, Syngenta
Formulation(s)  4 to 8 lb/gal soluble concentrate
Remarks  An organic, arsenic compound used as a selective, contact herbicide applied postemergence. Results are best when air temperature is above 80°F.
Water solubility  Very soluble
Storage conditions  Stable under moderate conditions.
Acute toxicity   LD50 - 1,359 mg/kg
Action in plant  Unknown
Site of action  Group 17: not well understood
Chemical family   Organoarsenical
NAPROPAMIDE
Trade name(s)  Devrinol
Manufacturer(s)  United Phosphorus
Formulation(s)  2 lb/gal emulsifiable concentrate; 10% granular; 50% wettable powder; 50% dry flowable
Remarks  A preemergence, soil-applied herbicide to control annual grasses and some annual broadleaf weeds. Little, if any, loss from soil surface by volatilization, but if sunlight is intense, loss by photodecomposition is fairly rapid.
Water solubility  73 ppm
Storage conditions  Store between 20° and 90°F.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits root growth.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family   Acetamide
NAPTALAM
Trade name(s)  Alanap-L
Manufacturer(s)  Chemtura
Formulation(s)  2 lb/gal soluble concentrate
Remarks  A selective, preemergence, phthalic acid herbicide. A nonvolatile chemical activated by moisture, it usually does not last more than 6 to 8 wk in soil. 
Water solubility  Acid 200 ppm; sodium salt 230,800 ppm
Storage conditions  Store below 140°F or it will precipitate. Crystals will form at freezing but will redissolve with agitation at warmer temperatures.
Acute toxicity   LD50 - 1,770 mg/kg
Action in plant  Inhibits transport of auxins; causes negative geotropism.
Site of action  Group 19: inhibits indole acetic acid transport
Chemical family  Phthalamate
NICOSULFURON
Trade name(s)   Accent
Manufacturer(s)  DuPont
Formulation(s)  75% water-dispersible granules
Remarks  A selective postemergence herbicide used at low rates in corn to control certain grass and broadleaf weeds. Carefully consider crop rotation plans prior to using.
Water solubility  360 ppm at pH 5.01; 39,200 ppm at pH 8.8
Storage conditions  Stable.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with plant enzyme acetolactate synthase, quickly stopping cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
NORFLURAZON
Trade name(s)  Evital, Solicam, Zorial, Predict, Solicam, Zorial 
Manufacturer(s)  Syngenta
Formulation(s)  80% wettable powder, 5% granule, 80% dry flowable
Remarks  A selective herbicide applied preemergence to control many grasses, sedges, rushes, pigweed, purslane, and ragweed.
Water solubility  28 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 10,000 mg/kg
Action in plant  Inhibits carotene formation, resulting in photodegradation of chlorophyll.
Site of action  Group 12: bleaching; inhibits carotenoid biosynthesis
Chemical family  Pyridazinone
ORYZALIN
Trade name(s)  Surflan
Manufacturer(s)  United Phosphorus
Formulation(s)  4 lb/gal flowable
Remarks  A selective preemergence herbicide. Oryzalin affects seed germination and inhibits root development. It is strongly adsorbed onto soil and resists movement by water.
Water solubility  2.5 ppm
Storage conditions  Store above 40°F. If frozen, warm and agitate.
Acute toxicity   LD50 - 10,000 mg/kg
Action in plant  Inhibits mitosis, primarily in roots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
OXADIAZON
Trade name(s)  Chipco Ronstar G, Ronstar, Ornamental Herbicide, Oxadiazon
Manufacturer(s)   Bayer CropScience, O.M. Scott
Formulation(s)  2% and 4% granular, 2 lb/gal emulsifiable concentrate, 50% wettable powder
Remarks  Selective preemergence control of annual grasses and broadleaf weeds in turf, woody ornamental shrubs, vines, and trees.
Water solubility  0.7 ppm
Storage conditions  Stable under moderate conditions.
Acute toxicity   LD50 - 8,000 mg/kg
Action in plant  Controls weed seedlings by contact action during emergence.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Oxadiazole
OXYFLUORFEN
Trade name(s)  Goal, Galigan, GoalTender, Oxiflo
Manufacturer(s)  Dow AgroSciences, Makhteshim Agan of North America
Formulation(s)  2 and 4 lb/gal emulsifiable concentrate
Remarks  Selective preemergence and postemergence control for grass and broadleaf weeds in several horticultural and agronomic crops. A contact herbicide; requires light for herbicidal activity.
Water solubility  0.1 ppm
Storage conditions  Store above freezing.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Acts as a contact-type herbicide. 
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether
PARAQUAT (restricted-use herbicide)
Trade name(s)  Gramoxone Extra, Gramoxone Max, Gramoxone Inteon, Cyclone, Cyclone Concentrate, Firestorm
Manufacturer(s)  Syngenta, Griffin, Chemtura
Formulation(s)  The cation part of the molecule is the active ingredient. 2, 2.5, and 3 lb/gal of the water-soluble cation. The formulation is a distinct green and contains a stenching agent to help prevent accidental swallowing. An emetic is added to induce vomiting in case it is consumed.
Remarks  A postemergence, nonselective, somewhat translocated herbicide with fast-acting contact action. Toxic if swallowed, inhaled, or absorbed through the skin. Use protective clothing to avoid inhaling or contact with the skin.
Water solubility  Completely soluble.
Storage conditions  Store above 32°F.
Acute toxicity   LD50 - 157 mg/kg
Action in plant  Acts as contact; absorbs energy produced during photosynthesis and forms peroxides that disrupt living cells.
Site of action  Group 22: photosystem I electron diversion
Chemical family  Bipyridilium
PEBULATE
Trade name(s)  Tillam
Manufacturer(s)  Syngenta, Monterey
Formulation(s)  6 lb/gal emulsifiable concentrate, 10% granular
Remarks  A preplant, soil-applied herbicide for weed control in tomatoes and sugar beets.
Water solubility  60 ppm
Storage conditions  Stable at moderate temperatures.
Acute toxicity   LD50 - 921 mg/kg
Action in plant  Inhibits mitosis in roots and shoots.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
PElargonic acid
Trade name(s)  Scythe 
Manufacturer(s)  Dow AgroSciences
Formulation(s)  4.2 lb/gal emulsifiable concentrate
Remarks  A contact, nonselective, broad-spectrum, foliar-applied herbicide. Nonsystemic and no soil residual.
Water solubility  Emulsifiable
Acute toxicity   LD50 - greater than 5,000 mg/kg (low toxicity)
Action in plant  Control or burndown of a broad spectrum of weeds on contact.
Site of action  Group  26: unknown
Chemical family  Carboxylic acid
PENDIMETHALIN
Trade name(s)  Pendulum, Pentagon, Prowl, Stomp, Repose, Hurdle, Prowl H2O, Stealth, Pendant, Pendimax
Manufacturer(s)  BASF, Olympic Horticultural, Dow AgroSciences
Formulation(s)  3.3, 3.8, and 4 lb/gal emulsifiable concentrate; 60% water-dispersible granules, 2% granular
Remarks  Depending on the crop, this is a selective, preplant, preemergence, and early postemergence herbicide that is used to control annual broadleaf and grass weeds.
Water solubility  0.5 ppm
Storage conditions  Store above 40°F. If frozen, redissolve at warm temperatures. Avoid flame and temperatures above 92°F.
Acute toxicity   LD50 - 3,380 mg/kg
Action in plant  Inhibits mitosis in roots and shoots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
PENOXSULAM
Trade name(s) Sapphire 
Manufacturer(s)   DowAgrosciences
Formulation(s)  0.31 lb ai/gal soluble concentrate
Remarks  Postemergence control of certain annual and perennial broadleaf weeds in certain established turfgrasses.
Water solubility  5.7 ppm at pH5, 410 ppm at pH 7 and 1,460 ppm at pH 9
Storage conditions  Store in a cool dry area
Acute toxicity LD50 - more than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Triazolopyrimidine
PHENMEDIPHAM
Trade name(s)  Betanal, Spin-Aid
Manufacturer(s)  Bayer CropScience
Formulation(s)  1.3 lb/gal emulsifiable concentrate
Remarks  A foliar-applied selective herbicide for weed control in sugar beets, spinach, and table beets. Do not exceed 21 gal/A of spray solution on a broadcast basis. Rain within 6 hours of spraying may reduce weed kill.
Water solubility  Less than 1 ppm
Storage conditions  Liquid thickens when frozen but returns to normal at warmer temperatures. Avoid use or storage near heat or flame.
Acute toxicity   LD50 - 2,000 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Phenylcarbamate
PICLORAM   (restricted-use herbicide)
Trade name(s)  Tordon 22K, Tordon K
Manufacturer(s)  Dow AgroSciences
Formulation(s)  2 lb/gal water-soluble concentrate
Remarks  A highly translocated, selective herbicide active through both foliage and roots on many broadleaf herbaceous weeds and woody plants. Picloram is persistent; diligently follow precautions to avoid injuring desirable plants. Unmetabolized picloram in treated foliage will pass through livestock, and manure and urine can be toxic to plants.
Water solubility  430 ppm
Storage conditions  Stable
Acute toxicity   LD50 - 8,200 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
PINOXADEN
Trade name(s)  Axial
Manufacturer(s)  Syngenta
Formulation(s)  0.83 lb/gal emulsifiable concentrate
Remarks  Selective postemergence grass-control herbicide. Controls several annual grasses in several small grains. Packed with an adjuvant that must be used with the herbicide.
Water solubility  20 ppm
Storage conditions  Store in a cool, dry place.
Acute toxicity   LD50  - 3,129 mg/kg
Action in plant  Inhibits fatty acid synthesis.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Phenylpyrazolin
PRIMISULFURON
Trade name(s)  Beacon
Manufacturer(s)   Syngenta
Formulation(s)  75% water-dispersible granules packaged in water-soluble packets.
Remarks  A selective postemergence herbicide used at low rates on field corn to control certain grasses and broadleaf weeds. Carefully consider crop rotation plans before using.
Water solubility  1 ppm at pH 5; 600 ppm at pH 8.
Storage conditions  Stable
Acute toxicity   LD50  - greater than 5,050 mg/kg
Action in plant  Interferes with plant enzyme acetolactate synthase, resulting in rapid cessation of cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
PRODiAMINE
Trade name(s)  Barricade, Endurance, Factor, RegalKade, Cavalcade
Manufacturer(s)  Syngenta, Regal Chemical Co.
Formulation(s)  65% water-dispersible granules
Remarks  A dinitroaniline compound that is applied preplant or preemergence depending on site used.
Water solubility  0.013 ppm
Storage conditions  Stable
Acute toxicity   LD50  - greater than 5,000 mg/kg
Action in plant  Inhibits mitosis in both shoots and roots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
PROMETON
Trade name(s)  Pramitol
Manufacturer(s)  Syngenta
Formulation(s)  25% emulsifiable concentrate (2 lb/gal), 80% wettable powder
Remarks  A triazine herbicide applied both preemergence and postemergence as a temporary total vegetation herbicide. Material has considerable foliar action and also acts through the roots.
Water solubility  750 ppm
Storage conditions  Store above 32°F.
Acute toxicity   LD50  - 2,276 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
PROMETRYN
Trade name(s)  Caparol, Prometryne
Manufacturer(s)  Syngenta, Platte
Formulation(s)  80% wettable powder, 4 lb/gal flowable
Remarks  A selective herbicide to control annual grass and broadleaf weeds.
Water solubility  48 ppm
Storage conditions  Stable.
Acute toxicity   LD50  - 3,750 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
PRONAMIDE (restricted-use herbicide)
Trade name(s)  Kerb, Break-Up
Manufacturer(s)  Dow AgroSciences, United Phosphorus, Inc.
Formulation(s)   50% wettable powder
Remarks  A selective herbicide to control annual and perennial grasses. For postemergence activity, pronamide must move into the root zone. There is little foliar uptake. Apply when temperature is below 55°F to reduce microorganism degradation.
Water solubility  15 ppm
Storage conditions  Store between 32° and 122°F under dry conditions. Do not remove package from original container except for immediate use.
Acute toxicity   LD50  - 5,620 mg/kg
Action in plant  Inhibits mitosis.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Benzamide
PROPACHLOR
Trade name(s)  Ramrod
Manufacturer(s)  Monsanto Co.
Formulation(s)   4 lb/gal flowable
Remarks  A selective, soil-active herbicide applied preplant or preemergence. No longer sold in the U.S.
Water solubility  613 ppm
Storage conditions  Store between 20° and 100°F. If frozen below 20°F, warm and mix.
Acute toxicity   LD50  - 1,900 mg/kg
Action in plant  Inhibits seedling roots and shoots.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family   Chloroacetamide
PROPANIL
Trade name(s)  Stam
Manufacturer(s)  United Phosphorus
Formulation(s)   3 and 4 lb/gal emulsifiable concentrate
Remarks  A contact herbicide to selectively control annual weeds in rice.
Water solubility  50,000 ppm
Storage conditions  Store above 32°F.
Acute toxicity   LD50 - 1,384 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Amide 
PROPOXYCARBAZONE
Trade name(s)   Olympus
Manufacturer(s)  Bayer
Formulation(s)   70% water-dispersible granule
Remarks  Postemergence herbicide used primarily to control annual grasses and some broadleaf weeds in winter wheat.
Water solubility  2,900 ppm at pH 4; 42,000 ppm at pH 7 and pH 9
Storage conditions  Store in cool, dry place.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the acetolactate synthase (ALS) enzyme, resulting in rapid cessation of cell division and plant growth in both roots and shoots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylaminocarbonyltriazolinone
PRosulfurON
Trade name(s)  Peak
Manufacturer(s)  Syngenta
Formulation(s)   57% water-dispersible granules
Remarks  A selective postemergence sulfonylurea herbicide used at low rates for annual broadleaf weed control in wheat, barley, oats, rye, triticale, grain sorghum, and proso millet. Carefully consider crop rotation plans before using.
Water solubility  87 ppm at pH 5; 43,000 ppm at pH 7.7
Storage conditions  Stable.
Acute toxicity   LD50 - 4,360 mg/kg
Action in plant  Interferes with plant enzyme acetolactate synthase, resulting in rapid cessation of cell division. 
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
PYRAFLUFEN
Trade name(s)  ET, Edict, Venue, Octane 
Manufacturer(s)  Nichino America
Formulation(s)  0.177 and 0.208 lb/gal emulsifiable concentrate
Remarks  A fast-acting postemergence contact herbicide.
Water solubility  82 ppb
Storage conditions  Store in a cool place.
Acute toxicity  LD50 - 3,712 mg/kg
Action in plant  Inhibits protoporphyrinogen oxidase (PPO) that disrupts cell membranes.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family   Phenylpyrazole
PYRASULFOTOLE
Trade name(s)  Huskie (also contains bromoxynil) 
Manufacturer(s)  Bayer Crop Science
Formulation(s)   2.08 lb/gal emulsifiable concentrate with bromoxynil.
Remarks  Controls broadleaf weeds in wheat, barley, and triticale. This formulation has a built-in safener to enhance crop safety.
Water solubility  69,100 ppm
Acute toxicity   LD50 - more than 2,000mg/kg 
Action in plant   Inhibits the HPPD enzyme, resulting in bleached plants.
Site of action  Group 28: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family  Isoxazole
PYRAZON
Trade name(s)  Pyramin
Manufacturer(s)  BASF Corp.
Formulation(s)  4.2 lb/gal emulsifiable concentrate, 68% dry flowable
Remarks  Selective preemergence and postemergence herbicide in sugar beets and red table beets. Material has little volatility. Needs moisture to activate.
Water solubility  400 ppm
Storage conditions  Store above 15°F. If frozen, warm and agitate.
Acute toxicity   LD50 - 647 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Pyridazinone
PYRIDATE 
Trade name(s)  Tough
Manufacturer(s)  Syngenta
Formulation(s)  5 lb/gal emulsifiable concentrate
Remarks  Postemergent, contact herbicide that controls annual broadleaf weeds in the two- to four-leaf stage. Label has been cancelled by the company; however, existing stock may be used until 12/31/09
Water solubility  1.5 ppm
Storage conditions  Store in freeze-free, dry area.
Acute toxicity  LD50  - 4,600 mg/kg
Action in plant  Blocks photosynthesis.
Site of action  Group 6: photosystem II inhibitor
Chemical family  Phenyl-pyridazine 
PYROXSULAM 
Trade name(s)  PowerFlex
Manufacturer(s)  Dow AgroSciences
Formulation(s)  7.5% water soluble granule (0.075 lb ai/lb)
Remarks  Postemergent annual grass and broadleaf herbicide for weed control in cereals
Water solubility  16.4 ppm at pH 4; 3,200 ppm at pH 7; 13,700 ppm at pH 9
Storage conditions Dry, well ventilated area 
Acute toxicity  LD50 - greater than 2,000 mg/kg
Action in plant  Interferes with an enzyme, resulting in inhibiting cell division
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Triazolopyrimidine sulfonamide
QUINCLORAC
Trade name(s)  Paramount, Drive, Drive XLR8
Manufacturer(s)  BASF
Formulation(s)  75% dry flowable, 1.5 lb/gal, and 1.5% granules
Remarks  Applied postemergence to actively growing weeds. Controls field bindweed and other selected weeds.
Water solubility  62 ppm
Storage conditions  Store under dry conditions.
Acute toxicity  LD50 - 2,610 mg/kg
Action in plant  Not fully understood. In broadleaves, similar to indole acetic acid. In grasses, inhibits cell wall synthesis.
Site of action  Group 4: synthetic auxin
Chemical family  Quinoline carboxylic acid
QuizaloFop
Trade name(s)  Assure II, Targa
Manufacturer(s)  DuPont
Formulation(s)  0.88 lb/gal emulsifiable concentrate
Remarks  A selective postemergence grass herbicide. Controls most annual and perennial grasses including quackgrass and Johnsongrass. A nonionic surfactant or crop oil concentrate is required for maximum effectiveness.
Water solubility  0.3 ppm at 68°F
Storage conditions  Do not store below 32°F.
Acute toxicity   LD50 - 5,700 mg/kg
Action in plant  Inhibits an enzyme (ACCase) that catalyzes the first step in fatty acid synthesis. This blocks production of new membranes required for cell growth.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
RIMSULFURON
Trade name(s)   Matrix, Resolve DF
Manufacturer(s)  DuPont
Formulation(s)   25% dry flowable
Remarks  A selective preemergence or postemergence herbicide to control weeds in potatoes. Rimsulfuron + thifensulfuron is marketed under the name Basis for use on field corn.
Water solubility  7,000 ppm at pH 7
Storage conditions  Stable. Do not store in moist conditions.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with the plant enzyme acetolactate synthase, rapidly stopping cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
SETHOXYDIM
Trade name(s)  Poast, Poast Plus, Prestige, Vantage
Manufacturer(s)  BASF, Nufarm
Formulation(s)   1, 1.3, and 1.5 lb/gal emulsifiable concentrate.
Remarks  A selective, postemergence herbicide to control most annual and perennial grasses. A crop oil concentrate enhances activity.
Water solubility  4,700 ppm at pH 7
Storage conditions  Store between -4°F and 86°F in sealed containers.
Acute toxicity   LD50 - 4,900 mg/kg
Action in plant  Inhibits growing points of grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
SIDURON
Trade name(s)  Tupersan
Manufacturer(s)  DuPont
Formulation(s)  50% wettable powder
Remarks  Selective herbicide; controls annual grass in turf.
Water solubility  18 ppm
Storage conditions  Stable under moderate conditions.
Acute toxicity   LD50 - 7,500 mg/kg
Action in plant  Apparently inhibits root growth.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
SIMAZINE
Trade name(s)  Princep, Simazine
Manufacturer(s)  Syngenta
Formulation(s)  80% wettable powder, 4 lb/gal flowable liquid, and 90% water-dispersible granules
Remarks  A triazine herbicide used selectively or as a complete vegetation killer. Requires considerable moisture to activate in soil. Shows long residual action.
Water solubility  3.5 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Triazine
SODIUM CHLORATE
Trade name(s)  Several
Manufacturer(s)  American Potash and Chemical Corp., Elf Atochem, Hooker Chemical, J. R. Simplot
Formulation(s)  40% soluble powder; 4%, 19%, and 28% liquid; 12% and 33% dust; 99% active material in powder form; also formulated with borates, sodium carbonate, calcium/magnesium chloride, 2,4-D, and others.
Remarks  Inorganic salt. Kills germinating seeds nonselectively; inhibits plant growth. Easily leached from soil.
Water solubility  790,000 ppm
Storage conditions  Stable at moderate conditions and when isolated from other pesticides.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Unknown.
Site of action  None generally accepted
Chemical family  Inorganic
SULFENTRAZONE
Trade name(s)  Spartan, Portfolio, Dismiss
Manufacturer(s)  FMC Corp.
Formulation(s)  75% dispersible granule, 4 lb/gal flowable liquid
Remarks  Soil-applied, preemergent triazolinone herbicide that can be applied either preplant incorporated or preemergence treatment. Note recropping intervals.
Water solubility  10 ppm at pH 5 and 300 ppm at pH 7
Storage conditions  Stable in dry, cool conditions.
Acute toxicity   LD50 - 2,416 mg/kg
Action in plant  Disrupts cell membranes by inhibiting protoporphyrinogen oxidase (PPO) in the chlorophyll biosynthetic pathway, leading to a buildup of toxic intermediates.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
SULFOMETURON
Trade name(s)  Oust, Spyder
Manufacturer(s)  DuPont, Nufarm
Formulation(s)  75% dispersible granules
Remarks  Broad-spectrum herbicide with preemergence and postemergence activity for noncropland and forestry use.
Water solubility  10 ppm at pH 5; 300 ppm at pH 7
Storage conditions  Stable.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Interferes with an enzyme, rapidly stopping cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
SULFOSULFURON
Trade name(s)  Maverick, Outrider, Certainty
Manufacturer(s)  Monsanto
Formulation(s)  75% water-soluble granule
Remarks  Preemergence or postemergence control of several grasses and some broadleaves in wheat and noncrop areas.
Water solubility  18 ppm at pH 5; 1,627 ppm at pH 7; 482 ppm at pH 9.
Storage conditions  Store in dry place below 120°F.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
TEBUTHIURON
Trade name(s)  Spike
Manufacturer(s)  Dow AgroSciences
Formulation(s)  80% dry flowable, 20% pellets
Remarks  A soil-applied herbicide to control woody plants and vegetation. Its half-life in soil is 12 to 15 mo in areas receiving 40 to 60 inches of annual precipitation.
Water solubility  2,300 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 568 mg/kg
Action in plant  Symptoms suggest photosynthesis inhibition.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
TEMBOTRIONE
Trade name(s)  Laudis
Manufacturer(s)  Bayer
Formulation(s)  3.5 lb/gal
Remarks  A selective postemergence herbicide for control of broadleaf and grass weeds in corn.
Water solubility  0.22 ppm at pH 4, 28.3 ppm at pH 7, 29.7 at pH 9 
Storage conditions  Store in a cool dry place
Acute toxicity  LD50  - greater than 2,000 mg/kg
Action in plant  Inhibits HPPD enzymes. 
Site of action  Group 27: inhibits 4-hydroxyphenyl-pyruvate-dioxygenase (HPPD)
Chemical family Triketone
TERBACIL
Trade name(s)  Sinbar
Manufacturer(s)  DuPont, NovaSource
Formulation(s)  80% wettable powder
Remarks  A substituted uracil compound; a preemergence and postemergence selective and nonselective herbicide. Controls a wide range of weeds.
Water solubility  710 ppm
Storage conditions  Stable at moderate conditions.
Acute toxicity   LD50 - 5,000 mg/kg
Action in plant  Inhibits photosynthesis.
Site of action  Group 5: photosystem II inhibitor
Chemical family  Uracil
THIFENSULFURON
Trade name(s)  Harmony, Harmony GT
Manufacturer(s)  DuPont
Formulation(s)  75% dry flowable
Remarks  A selective, postemergence herbicide with short soil persistence used at low rates to control certain broadleaf weeds in wheat and barley.
Water solubility  24 ppm at pH 4; 2,400 ppm at pH 6
Storage conditions  Stable.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with acetolactate synthase, resulting in a rapid cessation of cell division and plant growth in both shoots and roots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
TOPRAMEZONE
Trade name(s)  Impact 
Manufacturer(s)  Amvac Chemical Corp.
Formulation(s)  2.8 lb/gal suspension concentrate
Remarks  Topramezone is a novel 4-HPPD inhibitor herbicide for postemergence weed control in corn. It is effective against most major broadleaf weeds and has good activity on a number of grass weed species common to corn, including wild proso millet, while displaying excellent tolerance to all types of corn.
Water solubility  15,000 ppm at pH 7
Storage conditions  Store in a cool, dry place. If below freezing, agitate or mix contents of container well before use.
Acute toxicity   LD50 - greater than 2,000 mg/kg
Action in plant  Inhibits HPPD enzymes.
Site of action  Group 28: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family   Triketone
TRALKOXYDIM
Trade name(s)  Achieve
Manufacturer(s)  Syngenta
Formulation(s)  40% dispersible granule, 3.33 lb/gal soluble concentrate
Remarks  Used to control grasses in wheat and barley.
Water solubility  7 ppm
Storage conditions  Store in tightly sealed container.
Acute toxicity   LD50 - 934 mg/kg
Action in plant  Inhibits growing points in grasses.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
TRIALLATE
Trade name(s)  Far-Go
Manufacturer(s)  Monsanto Co., Gowan
Formulation(s)  4 lb/gal emulsifiable concentrate, 10% granules
Remarks  A selective herbicide for wild oat control, applied preplant or preemergence and incorporated. May irritate skin and eyes.
Water solubility  4 ppm
Storage conditions  Stable.
Acute toxicity   LD50 - 2,700 mg/kg
Action in plant  Inhibits shoots of emerging seedlings.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
TRIASULFURON
Trade name(s) Amber
Manufacturer(s)  Syngenta
Formulation(s)  75% water-dispersible granules packaged in water-soluble packets
Remarks  Selective, postemergence herbicide used in small grains to control certain broadleaf weeds. Carefully consider crop rotation plans before using.
Water solubility  40 ppm at pH 5; 1,500 ppm at pH 7
Storage conditions  Stable. Do not expose to light or moisture.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with the plant enzyme acetolactate synthase, thus rapidly ending cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
TRIBENURON
Trade name(s)  Express
Manufacturer(s)  DuPont
Formulation(s)  75% dry flowable
Remarks  A selective, postemergence herbicide with short soil persistence used at low rates to control certain broadleaf weeds in wheat and barley.
Water solubility  28 ppm at pH 4; 280 ppm at pH 6.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Interferes with acetolactate synthase, resulting in a rapid cessation of cell division and plant growth in both shoots and roots.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
TRICLOPYR
Trade name(s)  Garlon 3A, Garlon 4 Herbicide, Forestry Garlon 4, Forestry Garlon XRT, Remedy, Renovate 3A, Renovate OTF
Manufacturer(s)  Dow AgroSciences, SePro
Formulation(s)  3 lb/gal miscible liquid, 4  and 6.3 lb/gal emulsifiable concentrate, and a 10% granular flake
Remarks  A growth-regulating herbicide to control woody and broadleaf perennial weeds in noncropland, forestland, range, permanent grass pasture, turf, and rights-of-way. Crossbow is triclopyr + 2,4-D; Redeem R&P and Confront are triclopyr + clopyralid.
Water solubility  430 ppm
Storage conditions  Store above 35°F. Agitate before use if stored near freezing.
Acute toxicity   LD50 - 2,140 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
TRIFLURALIN
Trade name(s)  Treflan, Trifluralin, Tri-4, Trust
Manufacturer(s)  Dow AgroSciences, Griffin, Platte
Formulation(s)  4 and 5 lb/gal emulsifiable concentrate, 5% and 10% granules
Remarks  A dinitroaniline compound used as a selective, preemergence herbicide. Requires incorporation after application to prevent loss of activity. Residual activity from higher rates may be a problem with certain sensitive crops.
Water solubility  0.3 ppm
Storage conditions  Store the emulsifiable concentrate above 40°F.
Acute toxicity   LD50 - 2,000 mg/kg
Action in plant  Inhibits mitosis in shoots and roots.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
TRIFLUsulfUroN
Trade name(s)  UpBeet
Manufacturer(s)  DuPont
Formulation(s)  50% dry flowable
Remarks  A selective postemergence herbicide to control weeds in sugar beets.
Water solubility  3 ppm at pH 5; 110 ppm at pH 7
Storage conditions  Very stable. Formulated products do not freeze.
Acute toxicity   LD50 - greater than 5,000 mg/kg
Action in plant  Inhibits the plant enzyme acetolactate synthase, resulting in rapid cessation of cell division.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
2,4-D
Trade name(s)  Many
Manufacturer(s)  Dow AgroSciences, Helena, Nufarm, and others
Formulation(s)  Numerous acids, salts (amines usually), and esters. Sold as liquids, water-soluble powders, dusts (seldom used due to drift hazard), granules, and pellets.
Remarks  A selective, foliar-absorbed, translocated phenoxy herbicide used mainly in postemergence applications. 2,4-D is effective against many annual and perennial broadleaf weeds. Ester formulations are the most volatile, the amines least volatile. Plants are most susceptible when they are young and growing rapidly.
Water solubility  900 ppm
Storage conditions  Amine formulations are relatively stable, whereas esters depend on emulsifying system. Read each product label carefully.
Acute toxicity   LD50 - 300 to 1,000 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
2,4-DB
Trade name(s)  Butoxone, Butyrac, 2,4-DB 200
Manufacturer(s)  Albaugh, Winfield, and others
Formulation(s)  1.75 and 2 lb/gal emulsifiable and soluble concentrates, formulated as amine salts and esters, and 75% water-soluble powders.
Remarks  A phenoxy compound used as a selective, postemergence, translocated herbicide, particularly for broadleaf weed control in legumes. Material is beta-oxidized to 2,4-D very slowly by most legumes and rapidly by broadleaf weeds. Selectivity decreases with maturity of the legumes.
Water solubility  40 ppm
Storage conditions  Read each product label.
Acute toxicity   LD50 - 1,960 mg/kg
Action in plant  Mimics natural plant hormones.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
2,4-DP
See dichlorprop