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diphenamid (Dymid, Enide) Herbicide Profile 2/85

                                     diphenamid
      CHEMICAL NAME:      N,N-Dimethyl-2,2-diphenylacetamide (56)
      TRADE NAME(S):      Dymid, Enide (56)
      FORMULATION(S):     Available in 50 and 80% wettable powders; 4
                          pounds/gallon liquid dispersion, and 5% granules
                          (56).
      TYPE:               Selective preemergence herbicide
      BASIC PRODUCER(S):  TUCO, Div. of the Upjohn Co.
                          9540-190-14
                          Kalamazoo, MI 49001
      STATUS:             General use
      PRINCIPAL USES:     For control of annual grasses and broadleaf weeds
      in peanuts, tobacco seedbeds, field tobacco, tomatoes and peppers,
      okra, Irish potatoes, sweet potatoes, cotton, soybeans, strawberries,
      blackberry and raspberry (nonbearing), apple and peach trees, orange,
      lime and cherry trees (nonbearing), pine seedbeds, dichondra, iceplant,
      bermudagrass lawns and other ornamental plants (56).
           Combined with DNBP for usage on peanuts, potatoes and soybeans (8b).
      APPLICATION METHOD(S):  Diphenamid is a preemergence surface-applied
      herbicide.  Light rainfall or sprinkler irrigation following diphenamid
      application will improve its control of weeds.  Under conditions of
      dry weather following application of diphenamid, soil incorporation may
      increase the efficacy of the herbicide.  Diphenamid may be applied
      immediately after seeding the crop or over top of transplant crops any
      time after transplanting but prior to weed emergence (58).
                                    I.  EFFICACY
           Enide 90W for control of the following weeds:
      Grass Weeds
      ___________
      Annual bluegrass                         Goosegrass (Crowfoot grass)
      Annual sedge                             Johnsongrass (from seed)
      Barnyardgrass (watercress)               Ryegrass
      Cheat                                    Sandbur (Sandspur)
      Crabgrass                                Stinkgrass
      Fall panicum (Panic grass)               Wild Oat
      Foxtail                                  Witchgrass (Ticklegrass)
      Broadleaf Weeds
      _______________
      Carpetweed                               Mouseear chickweed
      Common chickweed                         Pigweed (Careless weed)
      Corn spurry                              Purslane
      Evening primrose                         Red sorrel
      Field pepperweed                         Shepherdspurse
      Florida pusley                           Smartweed
      Groundsel                                Spiny amaranth (Stickerweed)
      Knotgrass (German moss)                  Thymeleaf
      Knotweed                                 Sandwort
      Lambsquarters (50b).
           Germinated weeds are not controlled.  Important tolerant weeds
      include buffaloburr, ground cherry, horsenettle, Jimsonweeed, nightshade,
      velvetleaf, nutgrass, and established annual and perennial weeds.  Highly
      susceptible crop plants include barley, carrots, corn, millets, red
      beets, rye, sorghum, spinach, sugar beets, Swisschard, and wheat.
      No contact activity.  Weed control of 6-8 months duration can be
      expected.  Fall applications of 6 lbs./acre or more have greatly
      suppressed the growth of quackgrass.  Continued application should not
      result in a buildup in the soil (8b).
                             II.  PHYSICAL PROPERTIES
      MOLECULAR FORMULA:  C16 H17 N O (62)
      MOLECULAR WEIGHT:   239.3 (62)
      PHYSICAL STATE:     Colorless crystals (pure compound); off-white
                          solid (technical product) (62).
      ODOR:               No appreciable odor (pure compound) (58).
      MELTING POINT:      134.5 - 135.5 C (pure compound); 132-134 C
                          (technical product) (62).
      VAPOR PRESSURE:     Negligible at room temperature (pure compound) (62)
      SOLUBILITY:         260 mg/l water at 27 C (pure compound) (62)
                          III.  HEALTH HAZARD INFORMATION
      OSHA STANDARD:  NA
      NIOSH RECOMMENDED LIMIT:  NA
      ACGIH RECOMMENDED LIMIT:  NA
      TOXICOLOGY
           A.  ACUTE TOXICITY
               DERMAL:  LD50 = >225 mg/kg (rat) (62)
               No toxicity from application of 6.320 mg/kg to skin
      of rabbits.  No irritation from daily application of dry powder or 0.1%
      water suspension to abraded or unabraded skin of rabbits for 5 days.
      Guinea pigs were not sensitized to intradermal injections of a 0.1%
      diphenamid suspension (58).
               ORAL:  LD50 = 1050 mg/kg (rat) (62)
               LD50 (estimated) = 590 mg/kg (mouse), 970 plus or minus
      140 mg/kg (rat, adult), 270 plus or minus 20 mg/kg (rat, weanling), 290
      plus or minus 40 mg/kg (rat, newborn), 1500 mg/kg (rabbit), 1000 mg/kg
      (dog, male),  >1000 mg/kg (dog, female), >1000 mg/kg (monkey, male),
      >1000 mg/kg (monkey, female) (Dymid, 80% a.i.) (58).
               LD50 (estimated) = 1717 mg/kg (mouse), 1373 mg/kg (rat,
      adult) (Diphenamid) (58).
               INHALATION:  No toxicity to rats exposed 1 hour at 0.9
                            mg/liter (58).
               EYES:  No eye irritation occurred in rabbits from a dry powder
                      or a 0.1% water suspension applied to the conjunctival
                      sacs (58).
           B.  SUBACUTE AND CHRONIC TOXICITY:
           In 2-year feeding trials dogs and rats receiving 2000 mg/kg diet
      suffered no unusual effect on their physiology or fertility (62).
           Diphenamid was not toxic when administered for 90 days to rats at
      30 mg/kg or to dogs at 10 mg/kg (58).
           Safe feeding level, 2 years:  rats - 100 ppm in diet; dogs - 250
      ppm, in capsule administered daily (58).
                        IV.  ENVIRONMENTAL  CONSIDERATIONS
           General Toxicity to Wildlife and Fish:  Low (58).
      Behavior In or On Soils
      1.  Adsorption and leaching characteristics in basic soil types:
            Diphenamid is not tightly adsorbed on soil colloids.  It leaches
            rapidly in sandy soils but slowly in loam or clay soils.  In sandy
            soils, retention of an effective concentration in the weed seed
            germination zone with heavy rainfall can be a problem.
      2.  Microbial breakdown:  Microorganisms appear to play a significant
            role in degradation of diphenamid in soil.  Certain species of soil
            fungi are capable of metabolizing diphenamid in vitro.
      3.  Loss from photodecomposition and/or volatilization:  Diphenamid is
            nonvolatile and appears to be relatively stable in sunlight.
      4.  Resultant average persistence at recommended rates:  Long lasting
            weed control can be expected from recommended rates of diphenamid.
            Under warm, moist conditions the average persistence at herbicidal
            levels is from 3 to 6 months.  Under low rainfall conditions,
            diphenamid may be persistent in soil (58).
                      V.  EMERGENCY AND FIRST AID PROCEDURES
           The chemical information provided below has been condensed
      from original source documents, primarily from "Recognition and
      Management of Pesticide Poisonings", 3rd ed. by Donald P.  Morgan,
      which have been footnoted.  This information has been provided in
      this form for your convenience and general guidance only.  In
      specific cases, further consultation and reference may be required
      and is recommended.  This information is not intended as a sub-
      stitute for a more exhaustive review of the literature nor for the
      judgement of a physician or other trained professional.
           If poisoning is suspected, do not wait for symptoms to develop.
      Contact a physician, the nearest hospital, or the nearest Poison
      Control Center.
      SYMPTOMS OF POISONING:  Compound is an emetic to dogs and monkeys.
      Assumed to cause similar effects in man.  May induce convulsions (58).
           INGESTION:  Induction of vomiting and supportive treatment (58).
                        VI.  FIRE AND EXPLOSION INFORMATION
           Nonflammable (58).
                                VII.  COMPATIBILITY
          Compatible with most other wettable powder herbicidal formulations
      and fertilizers, if not highly alkaline.  Diphenamid wettable powder is
      not significantly influenced in its sprayability by water hardness.
      Diphenamid is not corrosive (58).
                            VIII.  PROTECTIVE MEASURES
      STORAGE AND HANDLING:  Harmful if swallowed.  Avoid prolonged or
      repeated contact with skin.  Do not use cover crops for food or feed
      within 6 months after application.  Avoid breathing dust.  Avoid
      contamination of feed or foodstuffs.  Keep out of lakes, streams, and
      ponds.  Do not contaminate water by cleaning of equipment or disposal
      of wastes or containers.  Do not contaminate water, food, or feed by
      storage or disposal (50b).
                       IX.  PROCEDURES FOR SPILLS AND LEAKS
                     IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
                                  (800) 424-9300
                      PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
                               X.  LITERATURE CITED
       8b. Thomson, W.T.  1981.  Agricultural chemicals - book 2:
               herbicides.  Revised ed.  Thomson Publications, Fresno, CA.
               274 pp.
      50b. TUCO, Division of the Upjohn Co.  1981.  Specimen label:  Enide 90W.
               Kalamazoo, MI.
      56.  Farm Chemicals Handbook, 70th ed.  1984.  R. T. Meister, G. L.
               Berg, C. Sine, S. Meister, and J. Poplyk, eds.  Meister
               Publishing Co., Willoughby, OH.
      58.  Weed Science Society of America, Herbicide Handbook Committee.
               1983.  Herbicide handbook of the weed science society of
               America, 5th ed.  Weed Science Society of America, Champaign,
               IL.  515 pp.
      62.  The Pesticide Manual:  A World Compendium, 7th ed.  1983.  C.R.
               Worthing, ed.  The British Crop Protection Council, Croydon,
               England.  695 pp.
      2/21/85