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    PESTICIDE RESIDUES IN FOOD - 1979


    Sponsored jointly by FAO and WHO






    EVALUATIONS 1979





    Joint meeting of the
    FAO Panel of Experts on Pesticide Residues
    in Food and the Environment
    and the
    WHO Expert Group on Pesticide Residues
    Geneva, 3-12 December 1979



    TRIADIMEFON

    IDENTITY

    Chemical Name:               1-(4-chlorophenoxy)-3,3-dimethyl-
                                 1-(1,2,4-triazol-1-yl) butan-2-one

    Synonyms:                    Bayleton(R)
                                 MEB 6447

    Structural formula:          C14H16C1N3O2

    CHEMICAL STRUCTURE 1

    Other Information on identity and properties

    Molecular weight:            293.7
    Appearance:                  Colourless crystals
    Melting point:               82.3°C (pure active ingredient)
    Vapour pressure:             <10-6 mbar at 20°C
                                 approx. 2 × 10 -5 mbar at 400C

    Solubility:                  in water  0.007 (pure a.i.)
    (g.a.i./100 g solvent        in cyclohexanone  60 - 120
    at approx. 20°C)             in isopropanol  20 - 40
                                 in ligroin  (80-110°C) 0 - 1
                                 in methylene chloride  >120
                                 in toluene  40 -60

    Minimum degree of purity:    90%
    Stability:                   Stable in 0.1 n H2SO4) for 24 hrs
                                 Stable in 0.1 n NaOH ) at 20°C

    Impurities in the technical material

    Detailed information on the impurities in technical triadimefon was
    reported to the meeting.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    Triadimefon is a new systemic broad-spectrum fungicide against plant
    pathogens, especially powdery mildew, loose smuts and rusts of cereals
    and other crops.  Its biochemical mechanism of fungicidal effect is
    believed to be founded on the inhibition of ergosterine synthesis
    (Buchenauer, 1975 and 1976).  It has been found to be taken up by
    plants from roots as well as through foliar surfaces and to be
    transported mostly with transpiration stream.  A certain translocation
    downwards through the plants, however, is also measurable.  Evidence
    is also given for a certain vapour phase activity, which is likely to
    support greenhouse applications.  It is used for the control of
    fungicidal diseases in several fruits and vegetables, in clover,
    cereals, ornamentals, etc. without observed signs of phytotoxicity.

    Triadimefon is registered and marketed for uses in agriculture and
    horticulture in a number of countries among which about 25 were
    reported to the meeting, representing most of the major agricultural
    regions of Africa, America, Asia, Australia and Europe.

    Pre-harvest treatments

    Triadimefon is used in various formulations including wettable powders
    (5 or 25%), emulsifiable concentrates (250 g per litre), dust (0.5%)
    or paste (2%) in pre-harvest use patterns and at rates shown in Table
    1.  Especially promise seems recently to be attached to the use of
    triadimefon in the control of mildew on cereal plants growing under
    temperate climatic conditions.

    Table 1.  Some uses of Triadimefon formulations

                                                                     
    Crop            Pest to be            Recommended conc./
                    controlled                 dosage
                                                                     

    Small fruits    mildew        0.0025-0.0% or 0.05-0.15 kg/ha

    Strawberry      mildew        75 - 100 g/ha

    Vegetables      mildew        0.0025-0.0125%  (field)
                                  0.0015-0.002%   (glass house)
                                  100 - 200 g/ha  (dusting

    Cereal crops    mildew        1 - 2 × 125 g/ha
                    rust          1 × 250 g/ha

    Coffee          rust          100 - 250 g/ha  (protective)
                                  250 - 500 g/ha  (eradicative)
                                                                     

    Table 1.  Continued...

                                                                     
    Crop            Pest to be            Recommended conc./
                    controlled                 dosage
                                                                     



    Pome fruits     mildew        2 × 0.008 - 0.01% (after flowering)
                    rust          or 0.04 - 0.075 kg/ha

    Mango           mildew        0.01%
                                  or 0.1 - 0.2 kg/ha

    Grape           mildew        0.0025%
                                  or 0.1 kg/ha (dust)

    Tobacco         mildew        0.0025 - 0.005%
                                  or 0.04-0.075 kg/ha
                                                                     

    Post-harvest uses

    No official recommendations have yet been reported for post-harvest
    uses of triadimefon, although some experimental trials indicate
    potential uses on pineapples.

    RESIDUES FROM SUPERVISED TRIALS

    Data on triadimefon residues resulting from extensive trials
    representing recommended use patterns have been presented by the
    originating manufacturer (Bayer AG, Leverkusen).  The data includes
    controlled field experiments under a variety of geographical and
    climatic conditions, as well as examples of greenhouse trials.  The
    data are presented in the following tables, and were obtained by gas
    chromatographic methodology which determines the parent compound,
    triadimefon, and its reduced, first metabolite, called triadimenol
    (see below under "Rate of Residues").  Results are presented as the
    sum of these two compounds, or in certain illustrative examples,
    individually.

    Fruit and Vegetables

    The data in Table 2 summarize results from supervised trials from
    various experimental sites in Germany (F.R.), and some other
    countries.  About a dozen different food crops of commercial interest
    are represented in the data, reflecting residue levels which can be
    expected after uses in accordance with "good agricultural practice".
    In several cases the residue data comprise triadimefon levels as well
    as contents of the triadimenol metabolite.  Generally, the triadimenol
    metabolite is found in levels which are comparable to the parent
    compound, but possibly with a slightly greater persistence.

    At the time of harvest and following recommended preharvest intervals,
    measurable residues in the order of 0.2 - 0.4 mg/kg are found in
    paprika and tomato and up to about 1.5 mg/kg in grapes.  In hops
    (harvested 10 days after treatment and measured after drying) total
    residues are significantly higher, i.e. from n.d. up to 8.1 mg/kg (in
    one individual sample 12.9 mg/kg).  Levels of triadimefon in most of
    the remaining examples are generally at or below 0.2 mg/kg.

    Cereal plants

    Residues of triadimefon, including triadimenol have been determined in
    extensive trials on growing cereal plants, e.g. barley, oat and wheat,
    with the results which are shown in Table 3.  Significant residues are
    found in all plants, heads as well as straw parts, and in all
    experiments from the tine of last application and during the following
    weeks.  At the time of harvest, i.e. 6 weeks after last treatment,
    residues are still persistent in straw at levels of 2 mg/kg or below.
    In one occasional sampling is found 8.2 mg/kg after high dosage
    treatment.  Separate determination of triadimefon and triadimenol
    shows that the majority of residue is in the converted triadimenol
    form already at day 14, as shown for one trial in Table 3.

    Grains at the time of harvest show no detectable residues in these
    experiments.

    Pineapples (post-harvest treatment)

    Residues in pineapples following a few experimental postharvest
    dippings or surface applications are shown in Table 4.  A penetration
    of triadimefon is hardly noticeable in these results, insofar as only
    low residue levels are found in the fruit flesh in comparison with the
    contents in peel.  A significant conversion, however, of triadimefon
    to triadimenol has obviously taken place between dipping and the time
    of analyses.

    Coffee and tobacco

    Trials on residues in beans and shells of coffee and in tobacco leaves
    are shown in Table 5.   Residues in tobacco leaves vary from 0.7 to
    8.5 mg/kg when analysed from 10-28 days after last treatment, and
    residues are practically fully converted to triadimenol.

    Must and wine after processing

    The possible transfer of residues of triadimefon, including
    triadimenol from harvested grapes to must and to processed wine is
    shown in Table 6.  A 50% level may be found in the must when related
    to the content in grapes.



        Table 2.  Residues of Triadimefon from Supervised Trials

                                                                                                   
                                        Days after         Residues (mg/kg)
    Crop           Application            last       Triadimefon    Triadimenol           Country
                   No. × Rate           treatment              Total
                                                                                                   

    Apple          12 × 0.04 kg/ha          0                <0.06-0.2                    FRG
                                            4                <0.06-0.2
                                            7                <0.06-0.15
                                           14                <0.06-0.15
                                           21                 n.d.-0.15
                                           28                 n.d.-0.2
                   6 × 0.05 kg/ha          14          n.d.-n.d.      n.d.-0.06           FRG
                                           21          n.d.-n.d.      n.d.-n.d.
                   12 × 0.05 kg/ha          0                 0.1-0.2                     FRG
                                            4                <0.06-0.1
                                            7                <0.06-0.1
                                           14                <0.06-0.1
                                           21                 n.d.-0.1

    Cucumber       8-1O × 0.07 kg/ha        0                <0.06-0.1                    FRG
                                            7                 n.d.-0.15
                                           10                 n.d.-0.1

    Cucumber       4 × 0.075 kg/ha          0                <0.06-0.006                  NL
    indoor                                  7                 n.d.-n.d.
                                           10                 n.d.-n.d.

    Currant        4 × 0.2 kg/ha            0                 0.65-3.35                   FRG
    red                                     4                 0.15-0.85
                                            7                 0.15-1.05
                                           10                 0.1-0.7
                                           14                <0.006-0.65


    Table 2.  Continued...

                                                                                                   
                                        Days after         Residues (mg/kg)
    Crop           Application            last       Triadimefon    Triadimenol           Country
                   No. × Rate           treatment              Total
                                                                                                   

    Grape          10 × 0.0625 kg/ha        0                 0.5 - 1.75                  FRG
                                           14                 0.15-1.25
                                           21                 0.1-1.65
                                           28                 0.03-1.4
                                           35                 0.03-0.95
                   10 × 0.05 kg/ha          0          0.8 - 1.0      0.15 - 0.2          FRG
                                           14          0.5 - 0.55     0.07-0.15
                                           21          0.45-0.3       0.1 - 0.1
                                           28          0.25-0.3       0.06-0.07
                                           35          0.25-0.15
                                           38                         0.02-0.06
                   6 × 0.1. kg/ha           0                 0.24-0.25                   SA
                                            3                 0.08-0.09
                                            7                 0.03-0.04
                                           14                 0.02-0.02

    Hops           4 × 0.5-1.0 kg/ha       10 days            n.d.-2.6
    dried                                  10 days            2.5-8.11
                                           10 days            2.0-12.9

    Melons         8 × 0.03-0.06 kg/ha      0                 n.d.-0.25                   F
                                            1                 n.d.-0.05
                                            4                 n.d.-0.15
                                            7                 n.d.-0.1
                                           10                 n.d.-0.08
                   2-4 × 0.0375 kg/ha       0         <0.01           <0.02               Jap.
                                            1         <0.01-<0.01     <0.02-<0.02
                                            5         <0.01-<0.01     <0.02-<0.02

    Onions         2-3 × 0.0875 kg/ha      10 days    <0.02-<0.02     <0.04-<0.04         Jap.
                                           21 days    <0.02-<0.02     <0.04-0.04
                                                                                                   

    Table 2.  Continued...

                                                                                                   
                                        Days after         Residues (mg/kg)
    Crop           Application            last       Triadimefon    Triadimenol           Country
                   No. × Rate           treatment              Total
                                                                                                   

    Paprika        6 × 0.125 kg/ha          0                 0.25-0.4                    It.
                                            1                 0.15-0.3
                                            4                 0.1-0.2
                                            7                 0.15-0.25
                                           10                 0.08-0.25

    Peas (without  2 × 0.03 kg/ha           0                   <0.1                      SA
    pod)                                    3                   <0.1
                                            7                   <0.1
                                           14                   <0.1

    Pumpkin        1 x× 12.5 g per 100/l.   0                 0.05-0.05                   SA
                                            3                 0.01-0.02
                                            5                <0.01-<0.01

    Strawberry     3-4x×0.075/0.1 kg/ha     0          0.09-0.15      n.d.-0.06           FRG
                                            1          0.07-0.11      0.04-0.06
                                            4          0.05-0.07      0.05-0.08
                                            7          0.05-0.07      0.07-0.12
                                           10          0.03-0.03      0.05-0.0.8
                                           14          0.02-0.025     0.04-0.10

    Sugarbeets     3 x1× 0.125 kg/ha        0          n.d.-n.d.      n.d.-n.d.           FRG
    roots                                  14          n.d.-n.d.      n.d.-n.d.
                                           21          n.d.-n.d.      n.d.-n.d.

    Sugarbeets     3 x1× 0.125 kg/ha        0          1.21-2.33      0.36-1.10           FRG
    leaves                                 14          n.d.-0.82      n.d.-0.37
                                           21          n.d.-n.d.      n.d.-n.d.
                                                                                                   

    Table 2.  Continued...

                                                                                                   
                                        Days after         Residues (mg/kg)
    Crop           Application            last       Triadimefon    Triadimenol           Country
                   No. × Rate           treatment              Total
                                                                                                   

    Tomato         2-4 x× 0.075 kg/ha       1          0.03-0.10     <0.02-0.10          Jap.
    indoor                                  5          0.02-0.04      0.04-0.10
                                           10         <0.01-0.02      0.04-0.06

    Tomato         6 x× 0.075/0.15 kg/ha    0                 0.2-0.4                     FRG
                                            1                 0.15-0.25
                                            4                 0.1-0.1
                                            7                 0.1-0.25
                                           11                 0.07-0.2
                                                                                                   

    *  FRG:  Germany (Federal Republic of Germany)
       F:    France
       It:   Italy
       Jap:  Japan
       NL:   Netherlands
       SA :  South Africa

    Table 3.  Residues in cereal crops after triadimefon treatments (FRG)

                                                                                                                          
                                                                                  Residues (mg/kg)
                  Application           Days after               Heads (grains)                          Straw
    Crop          No. × Rate              last           Triadimefon      Triadimenol         Triadimefon     Triadimenol
                                        treatment*                   Total                               Total
                                                                                                                          

    Barley        1 × 0.125 kg/ha           0                      2.7-3.15                            2.6-3.1
    (summer)                               14                      0.11-0.3                            0.3-0.45
                                           28                      n.d.-0.15                           0.2-0.25
                                           35                      n.d.-n.d.                           0.3-0.4
                                           42                      n.d.-n.d.                           0.4-0.4

    Barley        1 × 0.125 kg/ha           0                      4.1-5.2
    (S. Africa)                             4                      1.0-1.2
                                            7                      0.7-0.7
                                           14                      0.2-0.2
                                           40                      n.d.-n.d.

    Oats          1 × 0.125 kg/ha           0                      0.95-3.85                             1.8
                                           14                      n.d.-0.3                            0.2-0.6
                                           28                      n.d.-0.1                            n.d.-0.2
                                           35                      n.d.-0.2                            n.d.-0.15
                                           42                      n.d.-n.d.                           n.d.-0.4

    Wheat         1 × 0.125 kg/ha           0                      1.2-9.4                             1.1-10.45
    (summer)                               14                      0.15-0.95                           0.4-1.85
                                           28                     <0.05-0.75                           0.15-0.75
                                           35                      n.d.-0.15                           n.d.-1.05
                                           42                      n.d.-n.d.                          <0.15-0.6
                  2 × 0.125 kg/ha           0                      1.15-2.0                            2.5-5.0
                                           14                      0.2-0.35                            1.15-3.55
                                           28                      0.1-0.45                            0.5-0.9
                                           35                      n.d.-0.45                           0.1-1.6
                                           42                      n.d.-n.d.                           0.2-1.1
                                                                                                                          

    Table 3.  Continued...

                                                                                                                          
                                                                                  Residues (mg/kg)
                  Application           Days after               Heads (grains)                          Straw
    Crop          No. × Rate              last           Triadimefon      Triadimenol         Triadimefon     Triadimenol
                                        treatment*                   Total                               Total
                                                                                                                          

    Wheat         1 × 0.25 kg/ha            0                      5.0-18.1                            3.45-8.55
    (summer)                               14                      0.8-2.35                            1.4-3.35
                                           28                      0.15-1.3                            0.25-1.15
                                           35                      n.d.-n.d.                           0.65-1.0
                                           42                      n.d.-n.d.                           0.55-1.85
                  1 × 0.125 kg/ha           0             6.5-8.6          <0.1-0.71           1.76-4.6       <0.1-0.35
                  + 1 × 0.25 kg/ha         14             0.09-0.48         0.13-0.28          0.05-0.19       0.19-0.72
                                           28             n.d.-0.07         n.d.-0.18          n.d.-n.d.       n.d.-0.33
                                           35             n.d.-n.d.         n.d.-0.20          n.d.-n.d.       n.d.-0.44
                                           42             n.d.-n.d.         n.d. - n.d.        n.d.-n.d.       n.d.-0.52

    Wheat         1 × 0.125/0.25 kg/ha      0                      2.5-3.85                            1.3-3.8
    (winter)                               14                      0.2-0.8                             0.3-2.1
                                           28                      n.d.-0.8                            0.4-2.7
                                           35                      n.d.-0.95                           0.45-3.0
                                           42                      n.d.-n.d.                           0.85-2.4

                  2 × 0.25 kg/ha            0                      3.1-4.75                            5.9-9.95
                                           14                      0.4-1.05                            1.65-2.75
                                           28                      n.d.-1.75                           0.45-8.65
                                           35                      n.d.-2.55                           0.55-6.85
                                           42                      n.d.-n.d.                           0.45-8.2
                                                                                                                          

    *  Harvest at day 42 in all experiments
    


    Table 4.  Residues from post-harvest treatments of pineapple with
              Triadimefon (Bayer AG)

                                                                      
    Concentration/    Days after  Fruit         Residues (mg/kg)
    Treatment         treatment   part    Triadimefon     Triadimenol
                                                                      

    50 ppm/surface    13 days     Fruit   n.d.            n.d.
    application                   Peel    0.05            n.d.
                                  Total   <0.03           n.d.

    100 ppm/Dipping   13 days     Fruit   <0.03           <0.06
                                  Peel    1.1
                                          (0.96-1.23)     1.6(1.5-1.7)
                                  Total   0.23            0.33

    750 ppm/Dipping   13 days     Fruit   0.11            0.06
                                  Peel    6.4             2.6
                                          (6.28-6.5)      (2.4-2.8)
                                  Total   1.37            0.55
                                                                      



        Table 5.  Triadimefon Residues on Coffee and Tobacco (Bayer AG)

                                                                                                          
                                                      Days after              Residues (mg/kg)
    Crop                  Application                    last                                    
                                                      treatment         Triadimefon   Triadimenol   TOTAL
                                                                                                          

    Coffee
    (Brazil)     3 × 0.25 kg/tree                     51                   n.d.          n.d.
                 (or 3 × 0.025 kg/ha)(whole bean)
                 15 × 0.37 kg/tree                    32 (beans)            -             -          n.d.
                                                         (shell)            -             -          2.9

                 8 × 0.75 kg/tree                     89 (beans)            -             -         <0.1
                                                         (shell)            -             -          0.45

    Tobacco      2 × 0.06/0.09 kg/ha                  14                  <0.04       7.89-8.48       -
    (Japan)                                           28                  <0.04       2.09-2.13       -

                 2 × 0.075 kg/ha                      10                <0.04         2.92            -
                                                      23                <0.04         0.70            -
                                                                                                          
    

    Table 6.  Triadimefon residues during wine processing in FRG

                                                      

                             Residues (mg/kg)1
                                                  
                          1976             1977
                                                      

    Grapes             0.25 - 1.4       0.03 - 0.06

    Must               0.02 - 0.65      <0.04 - 0.06

    Wine               n.d. - 0.45*     n.d. - n.d.
                                                      

    1  Sum of triadimefon and triadimenol after GLC-analysis.
    *  An exceptionally high residue. (average below 0.1 mg/kg).


    Foods of animal origin

    In feeding experiments with cows, pigs, sheep and poultry, feed was
    given containing 56 or 180 mg/kg of triadimefon or triadimenol, and
    levels of residues were determined in potential food products at 1 or
    8 days after the termination of experimental feedings.  Residues
    resulting from these experimental feedings are shown in Tables 7 and
    8.

    The feeding levels are significantly higher than can be expected in
    actual feeding practices.  However, it is seen that residues from
    feeding with triadimefon only occasionally are found in meat from
    poultry, sheep and pig, and residues are not detectable in egg or milk
    products.  After feeding with the reduced metabolite triadimenol
    however, residues are found in abdominal fat samples of most animals
    at levels of 0.4 to about 7 mg/kg.  In egg or milk, including milk
    fat, residues are present only at or below the limit of determination.

    Residues measured as triadimenol were regularly found in offals from
    the slaughtered sheep, pig and poultry.  In all cases the triadimenol
    metabolite was practically only found irrespective of which of the two
    compounds were originally present in the feed.




        Table 7.  Residues of Triadimefon* in animal products after experimental feeding for 1 week
              (Bayer Australia 1978)

                                                                                                                                
                              Days                                            Residues (mg/kg)
                 Feeding      after                 Meat                           Fat                          Offals
    Animal        rate       feeding                                                                                            
                                         Triadimefon   Triadimenol      Triadimefon   Triadimenol     Triadimefon   Triadimenol
                                                                                                                                

    Feeding of Parent compound, Triadimefon:

    Poultry      180 ppm     1 day         <0.05         <0.08            <0.25          trace          <0.05          2.4
                             8 days        <0.05         <0.08            <0.25          <0.4           <0.05          1.7

    Sheep        56 ppm      1 day         trace         trace            <0.2           0.4            <0.1           1.9
                             8 days        <0.1          <0.1             <0.2           0.4            <0.1           1.9

    Pig          180 ppm     1 day         trace         trace            <0.65          trace          trace          0.2
                             8 days        <0.1          <0.2             <0.65          1.1            <0.1           0.2

    Feeding of metabolite, Triadimenol:

    Poultry      180 ppm     1 day           -           <0.08            -              trace            -            2.1
                             8 days          -           <0.08            -              <0.4             -            1.8

    Sheep        56 ppm      1 day           -           <0.1             -              2.2              -            3.4
                             8 days          -           trace            1.1 (?)        1.1              -            6.5

    Pig          180 ppm     1 day           -           <0.1             -              0.4              -            0.4
                             8 days          -            1.0             -              7.1              -            3.8
                                                                                                                                

    *  Determined by GLC-analysis of Triadimefon and Triadimenol separately.
    


    Table 8.  Residues of Triadimefon *) in milk and eggs after
              experimental feeding for one week (Bayer Australia, 1978)

                                                                
                                         Residues (mg/kg)
                     Feeding                                
    Product          level          Triadimefon    Triadimenol
                                                                

    After feeding the parent compound, Triadimefon:

    Milk, skimmed    168 ppm        <0.1 - <0.1    <0.1 - <0.1
    Milk fat         168 ppm        <0.4 - <0.4    <0.5 - <0.5
    Hen's egg        180 ppm        <0.1 - <0.1    n.d.- n.d.

    After feeding the metabolite, Triadimenol:

    Milk, skimmed    168 ppm             -         <0.1 - <0.1
    Milk fat         168 ppm             -         <0.5 - <0.5
    Hen's egg        180 ppm             -         <0.2 - <0.2
                                                                

    * Determined by GLC-analysis of Triadimefon and Triadimenol
      separately.


    FATE OF RESIDUES

    General remarks

    Degradation pathways and metabolite patterns of triadimefon in various
    media including soil, microorganisms, water, plants, animals and under
    exposure to light have been subject to many investigations from which
    illustrative summaries are presented in Figure 1 and Table 9.

    The principal metabolite of triadimefon (I) is already mentioned
    above,namely triadimenol (III) obtained by reduction of the >C=O
    group to >HCOH configuration.  Triadimenol is fungicidally active and
    seems to give promise as a commercial fungicide in its own rights.
    Indications are present that systemic properties of triadimefon may be
    ascribed to processes of uptake in the form of triadimefon combined
    with translocation of the metabolite, which is then considered to be
    the predominant active principle against fungal pests.

    Triadimenol occurs in two diastereoisomeric forms, called A and B,
    which are determined separately in metabolic studies.  Among other
    identified metabolites are mentioned cleavage products containing the
    triazole- or benzene-rings, i.a. 4-chlorophenol (VIII) from plant
    metabolic studies.  In animals, hydroxyl-(V,VI) and carboxyl-compounds
    (VII) are found, which represent non-disrupted molecule structures,
    and which may occur in free forms or as glucoronides.

    FIGURE 1



        Table 9.  Triadimefon and hitherto identified metabolites and their occurrence.

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    Formula  CHEMICAL STRUCTURE 1

    I      1-(4-chlorophenoxy)-        Triadimefon        X       X       X        X         X        X
           3,3-dimethyl-1-(1H          (BAYLETON)
           1,2,4-triazole-1-yl)-2
           butanone

    CHEMICAL STRUCTURE 2

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    II     1-(4-Chlorophenoxy)-        symmetrical                        X
           3,3-dimethyl-1-(4H-         isomer of I
           1,2,4-triazole-4-yl)-
           2-butanone

    CHEMICAL STRUCTURE 3

    III    1-(4-chlorophenoxy)-        Triadimenol        X       X       X        X         X        X
           3,3-dimethyl-1-             (BAYTAN)
           (1H-1,2,4-triazole-1-yl)-
           2-butanol

    CHEMICAL STRUCTURE 4

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    IV     1-(4-chlorophenoxy)-        isopropyl-                 X
           3-methyl-1-(1H-             analogue of I
           1,2,4-triazole-1-yl)
           2-butanone

    CHEMICAL STRUCTURE 5

    V      1-(4-chlorophenoxy)-        KWG 1323                                              X
           3-hydroxymethyl-3-
           methyl-1-(1H-1,2,4-
           triazole-1-yl)-2-butanone

    CHEMICAL STRUCTURE 6

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    VI     4-(4-chlorophenoxy)-        KWG 1342                                              X
           2,2-dimethyl-4-(1H-
           1,2,4-triazole-1-yl)-
           1,3-butandiole

    CHEMICAL STRUCTURE 7

    VII    4-(4-chlorophenoxy)-        Triadimenol                                           X
           3-hydroxy-2,2-dimethyl-     acid
           4-(1H-1,2,4-triazole-
           1-yl)-butane acid

    CHEMICAL STRUCTURE 8

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    VIII   4-chlorophenol                   -             X               X        X         X        X

    CHEMICAL STRUCTURE 9

    IX     4-chlorophenyl-                                                                            X
           methyl-carbonate                 -

    CHEMICAL STRUCTURE 10

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    X      3,3-dimethyl-l                   -                                                         X
           phenoxy-l-(1H-1,2,4
           triazole-1-yl)-2-
           butanone

    CHEMICAL STRUCTURE 11

    XI     1H-1,2,4-triazole           1,2,4-Triazole     X               X                           X

    CHEMICAL STRUCTURE 12

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    XII    Delta2-1,2,4-triazolin-           -                             X
           5-one

    CHEMICAL STRUCTURE 13

    XIII   4-Hydroxyphenyl-2-oxo-                                                                     X
           3,3-dimethyl-butane acid
           ester

    CHEMICAL STRUCTURE 14

                                                                                                          

    Table 9.  Continued...

                                                                                                          
    No.    Designation                 Designation                         Occurrence
                                       used in text                                                    
                                                         Soil   Fungi   Water    Plants   Animals   Light
                                                                                                          

    XIV    4-Hydroxyphenyl-2-hydroxy-       -                                                         X
           3,3-dimethyl-butane acid
           ester

    CHEMICAL STRUCTURE 15


    XV     4-Hydroxyphenyl-3,3-di           -                                                         X
           methyl-1-(1H-1,2,4-triazole
           1-yl)-2-butanol

    CHEMICAL STRUCTURE 16

                                                                                                          
    


    Fate in soil

    Adsorption and desorption studies determining the Freundlich isotherm
    characteristics have been made on triadimefon as well as on
    triadimenol in different soils and in different concentrations (Puhl
    and Hurley, 1978 a and b, Vogeler, 1978, Frohberger, 1978).  The
    results of such studies correlate well with laboratory leaching
    experiments in standardised procedures (BBA-Merkblatt no. 37) and
    TLC-mobility tests from which triadimefon can be classified as a
    compound of low mobility in a variety of soil types (Obrist and
    Thornton, 1977b, Thornton et al., 1976).

    No triadimefon was detected in leachates in the standardised test and
    only limited amounts of radiolabelled residues could be determined in
    soil layers below 2.5 cm in a balance study on treatment of spring
    barley with 14C-labelled triadimefon if measurements were made from
    76-427 days after application (Steffens & Wieneke, 1977).  In the
    leaching studies of Obrist and Thornton (1977b) less than 3% of the
    total radioactivity could be traced through 30 cm of aged soil after a
    period of 45 days with simulated rain of 12.5 mm per day.  None of
    this activity was identified as intact triadimefon or as triadimenol.
    Half-life determinations in two standard soils gave RL50-values of 60
    and 100 days for triadimefon and of 130 and 310 days for triadimenol
    (Bayer-reports Nos. 9012/1974 and 9050/1976).

    The disappearance rates of triadimefon and triadimenol have been
    studied by several groups in German, Japanese and U.S. trials under a
    variety of conditions and using a broad range of different soil types
    (Mango and Puhl, 1977a; Takase & Yashimoto, 1978; and reported from
    Bayer AG and Mobay Chem. Corporation).  Variations in RL50-values are
    found from about 10 days to 7 months for triadimefon and from about 3
    months to 500 days for triadimenol.  In summarising such data it is
    justified to characterize triadimefon, and especially triadimenol, as
    persistent compounds in soil, although it is presently impossible to
    evaluate which specific environmental conditions (e.g. soil type,
    temperature, etc.) are of greatest significance for the variability in
    persistence.  Residue levels of triadimefon have been determined in
    soil after several years of treatment in cereal fields and apple
    orchards (Bayer reports, 1977).  The residues consisted mainly of
    triadimenol which reached plateau levels (0-10 cm layer) from 0.13
    mg/kg to 0.65 mg/kg in the 5th years of trials in apple orchards.

    Residue uptake from soil, including crop rotation

    Uptake of triadimefon and triadimenol from soil was established in
    experiments with barley (Frohberger, 1978) and cloverplants (Fisher
    et al., 1979).  In the latter study a linear relationship between
    amount absorbed and the amount of triadimefon applied to the soil was
    found.  The uptake of soil residues by later crops have been studied
    by Steffen and Wieneke (1977), who used turnip and clover as catch
    crops followed by sugarbeet, oats or winter wheat as the main crops in
    lysimeters which had originally been treated with radio-labelled

    triadimefon on cultures of spring barley.  0.2% of soil residues was
    absorbed by the catch crops, while 0.5 - 4.3% was found in the
    following main crops.  It is assumed from these experiments that
    mainly triadimenol is absorbed from the soil, and subsequently
    metabolised to polar compounds in the plants.

    Soil metabolism

    The metabolic conversions and degradation of triadimefon in soil have
    been studied by Vogeler (1976a, 1977a and b), Mango & Puhl (1977a) and
    Takase & Yashimoto (1978).  It is found that a primary reduction to
    triadimenol takes place as a microbial reaction, and resulting into
    two diastereoisomeric forms, A and B, in ratios which differ from
    about 1:1 to 1:4 in the various experiments.

    In radio-labelled experiments Mango and Puhl (1977) applied
    triadimefon to soils using either benzene-ring or triazole-ring
    14C-labelling.  After 238 days they found 45-49% of radioactivity in
    triadimenol, 7% in triazole and 24% or 5% of 14CO2 from the two ring
    systems, respectively, indicating a complete, although gradual and
    relatively slow degradation of triadimefon.  After application on
    cereals, Vogeler in his experiments (using benzene-ring labelling)
    found 15-25% and 32-65% of soil radioactivity to be non-extractable.

    Fate in microorganisms

    As already mentioned, the conversion in soil of triadimefon to
    triadimenol under natural environmental conditions is considered to be
    a microbial reaction (Mango & Puhl, 1977).  This is confirmed in
    laboratory shake cultures of Aspergillus niger, which may convert
    from 5-32% of triadimefon to triadimenol in 2-5 days, respectively.
    No further metabolism of triadimenol was detected in these
    experiments.  In other experiments (Clark et al., 1978), triadimefon
    was incubated with mycelial mats of the fungus, and a different
    metabolic pattern was observed as indicated by the findings of an
    isopropyl analogue (IV) to triadimefon in the culture by mass
    spectrometric analysis.  And, in experiments by Pither (1979),
    combined bacterial or fungal cultures during 13 days had no detectable
    effects on triadimefon, leaving 99% of the parent compound intact in
    the cultures.

    Fate in water

    In sterile aqueous buffer solutions, triadimefon is found to be stable
    for many weeks at temperatures ranging from 25°C - 45°C and at pH 3,
    6, and 9 (Obrist and Thornton, 1976).  In a simulated pond
    environment, however, a fast degradation was found and metabolites
    identified in the following order: triadimenol (III), triadimefon
    symmetrical isomer (II), 1,2,4,triazole (XI) and
    Delta2-1-2-4-triazolin-5-one (XII) (Obrist et al., 1977a).  30% of
    the 14C activity (from benzene-ring labelling) was missing at the end
    of the experiment, possibly under formation of 14CO2.  The

    disappearance rate for the parent compound in these experiments
    corresponded to half-lives of 6-8 days in the water phase and 18-20
    days in the silt.

    Fate in plants

    An uptake of triadimefon from soil to plants, e.g. to beans and barley
    (Buchenauer, 1975 and 1976) and through foliar surfaces to beans,
    cereals, cucumbers and tomato followed by translocation with the
    transpiration stream (i.e. acropetally) has been demonstrated in
    several studies (Steffens & Führ, 1976; Scheinpflug et al., 1977b;
    Brandes et al., 1978; Für et al., 1978; Gasztony & Josepovits,
    1978).  A slight translocation in the opposite direction, i.e.
    basipetal movement, is observed also (cfr. Buchenauer, 1975 and 1976).

    A transfer of triadimefon through the vapour phase with a measurable
    fungicidal effect and evidence of metabolites in untreated plants is
    described in studies from greenhouses (Scheinpflug & Paul, 1977a;
    Schlüter, 1977; Scheinpflug et al., 1978; Kraus, 1979) and in closed
    glass chambers (Vogeler & Paul, 1976b).  Such vapour phase effects are
    dependant on the distance between target plant and spray deposits.

    As is the case for soil, there is much experimental evidence that
    triadimefon is reduced in plants to triadimenol, which is the major
    metabolite (up to 80%) and which occurs in the two diastereoisomeric
    forms, A and B.  Contrasting the situation in soil, however, the
    isomer form A is dominating as indicated by the ratios of A:B varying
    from 1:1 to 3:1.  Besides triadimenol, polar substances (Rf values of
    0) and a compound with the Rf value of 0.26 (presumably compound VI
    in Table 9) were found.

    Results from experimental determinations of various 14C labelled
    metabolites and fractions in cereal plants (benzene-ring label) and in
    apples (triazole-ring label) are shown in Table 10.



        Table 10.  Percent distribution of radioactivity in cereals and apples after spray application of 14C-Triadimefon
               (recovered radioactivity = 100) (Vogeler, 1976, 1977, 1978; Mango et al., 1977)

                                                                                                                                             
                                                                                          EXTRACTABLES
    Plant            Dose         Days                                                                                                       
    (I = Indoor      (a.i.)       post     RF 0      RF 0.26+    unidentified   Triadimenol A   Triadimenol B   Triadimefon       non
     F = Field)                   appl.                          metabolite                                                   extractables
                                                                                                                                             

    barley (I)
    total plant                     0      n.d.        n.d.          n.d.           n.d.            n.d.           99.5           0.5
      "     "                       5      7.3         n.d.          n.d.           57.3            21.8            9.7           3.9
      "     "                      10      15.8        n.d.          n.d.           50.3            18.9            7.9           7.1
      "     "        250 g/ha      28      15.8        n.d.          n.d.           45.1            17.4            6.4          15.3
    straw                          38      15.9        n.d.          n.d.           43.6            14.4           10.3          15.8
      "                            62      16.7        1.9           n.d.           41.0            17.3            4.8          18.3

    barley (F)
    total plant                     0      <1          n.d.          n.d.            1              n.d.           92             6
      "     "                       5      13          n.d.          n.d.           48              15             12            12
      "     "        125 g/ha      17      35          n.d.          n.d.           32              10             <1            23
    straw                          28       9          <1            n.d.           12               4             n.d.          75
      "                            76       8.4         5            n.d.            8.4             3             n.d.          75

    wheat (F)
    straw            250 g/ha      47      37           2            n.d.           23               6             n.d.          32

    apples (F)
    peel                           28      5.7*        n.d.          2.8            14.9            13.6           10.8          5.0
    pulp                                   5.3*        n.d.          3.1            11.2            7.1            2.1           0.9
    total fruit      15 mg/100ml           11.0*       n.d.          5.9            26.1            20.7           13.0          5.9
    peel                           48      4.8*        n.d.          1.5            14.5            14.8           10.4          6.0
    pulp                                   6.4*        n.d.          2.1            10.4            9.4            2.1           1.0
    total fruit                            11.2*       n.d.          3.6            24.9            24.2           12.5          7.0
                                                                                                                                             
    +  presumably compound VI, table 9.
    n.d. = not detectable  *  aqueous phase
    The amount of radioactivity in grains and ears was too small for separation by TLC.
    


    FATE IN ANIMALS

    Mammals

    Following administration of a single oral dose of 14C-triadimefon of
    25 mg per kg b.w. to rats, it was found that 75 - 83% was excreted
    within 7 days, with 30-40% in the urine and 35-53% in the faeces.
    Expiration of 14CO2  was not found (Fredrickson, 1978a).  In cows as
    well as in pigs (Fredrickson, 1978b; Pither, 1978), 84-91% of
    triadimefon doses of 0.14 or 5 mg/kg, respectively, was excreted with
    the urine within 48-72 hours after oral administration.  Less than 6%
    was excreted in faeces.

    Evidently, triadimefon is readily absorbed by the animals and
    subsequently metabolised in the animal organism in the transitional
    period before excretion.  Analytical determination of the distribution
    between tissues, fat and organs have been made on rats and cows
    (Fredrickson, 1978 a and b), pigs (Pither, 1978) and poultry (Nye,
    1979).

    Results from these studies are summarised in Table 11.  This table
    shows the peak levels which are found shortly after oral
    administration of triadimefon at the dosages which are indicated, and
    the remaining residues found after 4-7 days of post-treatment
    elimination period.

    The metabolic pattern of triadimefon has been followed in most of
    these feeding studies with the unequivocal identification of the
    metabolites V, VI and VII (cfr. Figure 1 and Table 9) in most tissues
    and organs from rat, cow, pig and hen.  These metabolites are formed
    by stepwise oxidation of the tert. butyl group of triadimefon into
    primary alcohol and to carboxylic acid that are eliminated with the
    urine, in which they are identified in free forms or as conjugates of
    glucoronic acid together with other and unidentified polar
    metabolites.  As part of these studies it has been found that milk
    contained 0.003 mg/kg triadimefon after 5 daily doses of 0.14 mg/kg.
    Eggs from hens which had been given one dose of 2.4 mg/kg showed 0.12
    mg/kg after 24 hours and 0.04 mg/kg after 96 hours.

    Fish

    The accumulation and persistence of residues was studied in Channel
    catfish (Ictalurus punctatus) under continuous exposure to
    radio-labelled triadimefon for a 28-day period at concentrations of
    approximately 10 and 100 ppb (µg/l) in water (Lamb and Roney, 1977).
    Concentration factors of 7.6 and 6.5, resp. were determined from the
    two levels.  After transfer to uncontaminated water 88% of the
    accumulated 14C residues were excreted by the fish within 5 hours and
    approximately 96% within the following 7-10 days.



        Table 11.  Residues in animal tissues after oral administration of triadimefon.

                                                                                                                            
              Days ×                                              Residues (mg/kg)*
              dose (mg/    Time after                                                                           Reference
    Animal    kg b.w.)     administr.      Muscle           Fat         Liver          Kidney        Egg
                                                                                                                            

                                                                       approx.         approx.
    Rat       1 × 25       2 - 8 hrs       4.5-8.0       43.5-45.0     26 - 29         11 - 17                  Fredrickson
                           7 days         0.01-0.02      0.02-0.09    0.10-0.14       0.02-0.08                 1978a

    Cow       1 × 10       1 - 2 hrs.       0.36           4.01         3.65            15.0                    Fredrickson
              5 × 0.14     1 - 2 hrs.       n.d.           n.d.         0.08            0.05                    1978b

    Pig       5 × 5        3 hrs.           0.30           1.0          3.1             4.0                     Pither, 1978

    Hen       1 × 2.4      6 hrs.           0.12           0.3          0.26            1.18         0.12       Wye, 1979
                           96 hrs.         <0.01          <0.01        <0.01           <0.01         0.04
                                                                                                                            

    *  Sum of triadimefon and triadimenol after GLC-analysis
    


    Photodegradation

    The pattern of photodecomposition of triadimefon and of triadimenol
    have been studied in a number of individual tests by exposure to
    UV-light of the compounds in solution (or suspension) or on a solid
    support, e.g. silicagel plate or silty clay loam soil surfaces
    (Vogeler, 1975; Clark et al., 1978; Wilmes, 1978; Nicholas et al.,
    1977; Obrist and Thornton, 1978; Takase and Hasebe, 1979).  Several of
    the reaction products after such exposures are shown in Figure 1 and
    Table 9, from which it is evident that the abiotic molecular breakdown
    differs considerably from the patterns already described in plant and
    animals.  Among compounds which are identified in several of the tests
    are especially mentioned 1,2,4-triazole (XI), 4-chlorophenol (VIII)
    and 4-chlorophenyl methyl carbonate (IX).  Also mentioned is the
    formation of high molecular polymers as well as fully degraded 14CO2
    as the result experimental irradiation.

    As has been found in most of the other media, triadimenol proves to be
    more stable to photodegradation than triadimefon.  An experimental
    half-life of 10-12 hours for the latter under specified light
    conditions (in water) compares with 36 hours for the triadimenol.

    EVIDENCE OF RESIDUES IN FOOD IN COMMERCE OR AT
    CONSUMPTION

    No information was reported to the meeting.

    METHODS OF RESIDUES ANALYSIS

    Residues of triadimefon and its primary metabolite, triadimenol, which
    is also a fungicidal chemical, can be measured by gas chromatographic
    multiresidue methodology developed by Specht (1977) and modified by
    others (Thornton et al., 1977; Thornton and Lloyd, 1977).  In
    principle this method is based on extraction of the fungicides with
    acetone or methanol with addition of a specified amount of water,
    followed by partitioning between acetone-water and dichloromethane.
    After evaporation of the dichloromethane, the extract is
    chromatographed on a Florisil column with 6% (v/v) ethyl ether in
    petroleum and 40% (v/v) ethyl acetate in petroleum ether.  The second
    eluate is concentrated and gas chromatographed using an AFID
    (nitrogen-specific) detector.

    In this analysis triadimefon, and the two diastereoisomeric forms, A
    and B of triadimenol are determined separately.  The method is
    applicable for the analysis of various plant materials and soils for
    which it has been validated and found to have lower limits of
    determination of 0.03 mg/kg (triadimefon) and 0.06 mg/kg (triadimenol)
    in soil and in plant material containing more than 80% of water, and
    0.05 mg/kg (triadimefon) and 0.1-0.15 mg/kg (triadimenol) in grain and
    straw of cereals.  Recoveries are found as 89-98% in green plants,
    80-99% in straw, and 90-99% in grains.  Various fruit and vegetables
    are quoted for recoveries in ranges from 80-100%.

    NATIONAL LIMITS REPORTED TO THE MEETING

    National limits and associated pre-harvest intervals which have been
    reported to the meeting are shown in Table 12.

    APPRAISAL

    Triadimefon is a systemic fungicide used against mildew, rust and
    other fungi on cereals, vegetables and fruit crops as well as
    ornamentals.  It is marketed in many countries in formulations of
    wettable powders, emulsifiable concentrates, dusts or pastes.  It is
    often used in foliar spraying programmes with repeated applications at
    low dosages.  Information on the impurities in technical triadimefon
    was reported to the meeting.

    It is probable that the systemic properties of triadimefon arise from
    uptake of the parent compound through root or plant surfaces, followed
    by reduction to and translocation of the major metabolite,
    triadimenol, which presumably is the carrier of the fungicidal
    activity.  Such processes start shortly after application of
    triadimefon to plants so that triadimenol dominates the residue
    constituent at the end of normal pre-harvest waiting periods.  Polar
    metabolites, including 4-chlorophenol, as conjugates have been
    identified as further metabolites in plant material.

    At the time of harvest and following recommended preharvest intervals,
    measurable residues up to about 2.0 mg/kg may be found in various
    crops, whilst for various other crops the residues are at or below
    limit of determination.  Whilst the meeting was prepared to recommend
    limits for crops in the latter cases, it was considered that the
    experimental data for hops, coffee and tobacco, as well as for
    pineapples after post-harvest treatments were insufficient.  More
    information on actual use patterns and related residue data should be
    made available to enable recommendations to be made concerning those
    crops.

    Table 12.  National Limits and Preharvest intervals Reported to the
               Meeting

                                                                      
                                           Limit       Pre-harvest
    Country         Crop                   (mg/kg)     interval (days)
                                                                      

    Austria         Cereals                  1               35
                    Beets                    0.2             35
                    Grape, pome fruit        1               35
                    Cucumber, tomato,        1                4
                    paprika

    Belgium         Wheat, barley                            42

    Table 12.  Continued...

                                                                      
                                           Limit       Pre-harvest
    Country         Crop                   (mg/kg)     interval (days)
                                                                      

    Brazil          Wheat                    0.01            42

    Denmark         Cereals                                  28
                    Pome fruit                               14

    France          Apple                    1               7
                    Melon                    1               3

    Germany         Cereals                                  35
    (F.R.)          Cucumber                                  3
                    Apple                                    14
                    Grape                                    35

    Israel          Wheat                                    42

    Netherlands     Wheat, barley                            42

    N. Zealand      Apple                                    49
                    Cereals                                  49
                    Grapes                                   28

    Norway          Apple, strawberry                        14
                    Cereals, berries                         28


    S. Africa       Apple                    0.05
                    Barley                   0.1             40
                    Cucumber                 0.05            3
                    Grape                    0.05            7
                    Mango                    0.05

    Yugoslavia      Cereals                                  35
                    Cucumber                                 7
                    Other crops                              21
                                                                      

    Metabolism and degradation in animals, soil, microorganisms and water
    as well as patterns of abiotic photodecomposition of triadimefon have
    been studied extensively, and detailed lists of possible metabolites
    and breakdown products are available.  Triadimefon and especially
    triadimenol are eliminated from tissues of livestock at relatively
    fast rates, resulting in residues at or below limit of determination
    within one or a few days in meat, milk and egg-products.  In fat and
    in offals from slaughtered animals, however, significant residues of
    triadimenol may be obtained.

    Convenient multi-residue methodology based on gas chromatography is
    available for the determination of triadimefon and triadimenol in food
    and food products.

    RECOMMENDATIONS

    As no ADI had been allocated the meeting proposed the following
    Guideline Level on a basis of taking into account the preharvest
    intervals indicated.  The GLs refer to the sum of the parent compound
    triadimefon and its major metabolite, triadimenol.

                                                                        
                           Guideline       Pre-harvest interval on
    Commodity              Level(mg/kg)    which recommendation is based
                                                                        

    Apples                 0.2             14 days
    Cucumbers (indoor
    and outdoor)           0.2             3 days
    Currants, red          1               14 days
    Eggs                   0.1*
    Grapes                 2               28 days
    Melons                 0.5             4 days
    Milk                   0.1*
    Onions, spring         0.1*            21 days
    Paprika                0.5             3 days
    Peas, without pods                     0.1*  3 days
    Pumpkins               0.1*            3 days
    Strawberries           0.2             7 days
    Sugar beets, roots                     0.1*  21 days
    Sugar beets, leaves                    0.1*  21 days
    Tomatoes, (indoor
    and outdoor            0.5             3 days
    Grain (barley,
    oats, wheat)           0.1*            42 days
    Straw (barley,
    oat, wheat)            2               42 days
                                                                        
    (* At or about the limit of determination)

    FURTHER WORK OR INFORMATION

    Desirable

    1.  Feeding studies on livestock animals for establishing
        dose-response relationship between feed contents and residues in
        animals tissues, especially fat, and including realistic feeding
        levels;

    2.  Further information on residue levels in certain products, such as
        coffee and hops and in pineapples after appropriate post harvest
        treatments.

    REFERENCES

    Bayer AG.  Various reports on triadimefon residues in fruit,
    vegetables and soil, as well as from animal experiments.  Bayer AG,
    Leverkusen, FRG. (1975/79), Unpublished.

    Brandes, W., Steffens, W., Führ, F., Scheinpflug, H. - Weitere
    Untersuchungen zur Translokation von 14C-Triadimefon in
    Gurkenpflanezen. Pflanzenschutz Nachrichten Bayer 31, 132-144.

    Mobay Reports.  Various unpublished reports prepared by the Research
    and Development Dept., Agricultural Chemicals Division, Mobay Chemical
    Corporation, Kansas City, Mo. 64 120, U.S.A.

    Buchenauer, H. - Systemisch-fungizide Wirkung und Wirkungsmechanismus
    von Triadimefon (MEB 6447). Mitt. Biol. Bundesanst. Land-Forstwirtsch.
    (Berlin Dahlem) 165, 154-155.


    Untorsuchungen zur systemischen Wirkung und zum Einfluss von
    RBAYLETON (Triadimefon) auf verschiedene pilzliche
    Getreidekrankheiten. Pflanzenschutz-Nachrichten Bayer 29, 267-280.

    Clark, T., Clifford, D.R., Deas, A., Gendle, P., Watkins, D.
    Photolysis, metabolism and other factors influencing the performance
    of triadimefon as a powdery mildew fungicide. Pest. Sci. 9, 497-506.

    Fisher, D.J., Pickard, J.A., McKenzie, C.M. - Uptake of the systemic
    fungicide triadimefon by clover and its effect on symbiotic nitrogen
    fixation. Pest. Sci. 10, 75-82.

    Fredrickson, D.R. - Metabolism of BAYLETONTM in Rats.  Mobay Report
    No. 66 201, June 20, (1978a).

    Metabolism of BAYLETONTM in the cow. Mobay Report No. 66, 202,
    June 20, (1978b).

    Frohberger, P.E. - Zur Frage der Biologischen Aktivität von
    BAYLETON-Rück-standen im  Boden. BAYER AG.
    Pflanzenschutz-Anwendungstechnik, unpublished report April 12, 1978.

    Für, F., Paul, V., Steffens, W. and Scheinpflug, H.  Translokation von
    14C-Triadimefon nach Applikation auf Sommergerste und sein Wirkung
    gegen Erysiphe Graminis var. hordei. Pflanzenschutz-Nachrichten Bayer
    31, 116-131.

    Gasztony, M., Josepovits, G. - Translocation and metabolism of
    triadifflefon in different plant species. Acta Phytopathologica
    Academiae Scientiarum Hungaricae, 13, 403-415.

    Kraus, P. - Untersuchungen zur Wirkung von BAYLETON aus dem Boden über
    die Gaphase gegen Erysiphe graminis an Gerste. BAYER AG,
    Pflanzenschutz Answendungstechnik, unpublished report, February 8,
    1979.

    Lamb, D.W., Roney, D.J. - Accumulation and Persistence of Residues in
    Channel Catfish Exposed to BAYLETON TM-14C. Mobay Report No. 52 775,
    May 4, 1977.

    Mango, R.R., Puhl, R.J. - The Aerobic and Anaerobic Soil Metabolism of
    BAYLETONTM. Mobay Report No. 51 230, January 12, (1977a).

    Mango, R.R., Puhl, R.J. and Thornton, J.S. - The Metabolism of
    BAYLETON in Apples. Mobay Report No. 53 621, August 9, (1977b).

    Nichols, S.S., Thornton, J.S., Publ, R.J. - Photodecomposition of
    BAYLETONTM in Water solution. Mobay Report No. 52 688, April 6,
    1977.

    Nye, D.E. - The Fate of RBAYLETON-14C in Poultry. Mobay Report No.
    67 482, March 8, 1979.

    Obrist, J.J., Thornton, J.S. - Stability of BAYLETONTM in Sterile
    Aqueous Buffer Solutions. Mobay Report No. 50 799, November 29, 1976.

    Obrist, J.J., Publ, R.J. and Thornton, J.S. - The Degradation and Fate
    of BAYLETONTM in a simulated pond environment. Mobay Report No. 53
    038, May 31, (1977a).

    Obrist, J.J. and Thornton, J.S. - Leaching characteristics of
    BAYLETONTM on Aged soil. Mobay Report No. 51 232, January 21, 1977b.

    Photodecomposition of RBAYTON in Aqueous solutions and on a soil
    surface. Mobay Report No. 66 794, October 20, 1978.

    Pither, K.M. - Metabolism of BAYLETONTM in Male and female pigs.
    Mobay Report No. 66 509, November 29, 1978.

    Degradation of RBAYLETON by Mixed cultures of microorganisms.
    Mobay Report No. 67 049, January 30, 1979.

    Puhl, R.H., Hurley, J.B. - Soil Adsorption and desorption of
    BAYLETON-Ring UL14C. Mobay Report No. 66 501, September 11, (1978a).

    Soil adsorption and desorption of BAYTON-II. Mobay Report No. 66
    745, December 12, (1978b).

    Scheinpflug, H. and Paul, V. - On the mode of action of Triadimefon.
    Neth. J. Plant  Path. 83, (Suppl.1), 105-111. (1978a).

    Scheinpflug, H., Paul, V. and Kraus, P. - Untersuchungen zur
    Wirkungsweise von BAYLETON bei Getreidekrankheiten. Mitt. Biol.
    Bundesanst. Land Forstwirtsch. (Berlin-Dahlem) 178, 178. (1978b).

    Scheinpflug, H., Paul V., and Kraus, P. - Untersuchungen zur
    Wirkungsweise von BAYLETON bei Getreidekrankheiten. Pflanzenschutz -
    Nachrichten Bayer 31, 101-115.

    Schlüter, K. - Fungizide Wirkung von Triadimefon in der Gasphase. Z.
    Pflanzenkr. Pflanzenschutz 84, 612-614.

    Specht, W. - Gas Chromatographic method for determining residues of
    the fungicides  fuberidazol, fluotrimazole and triadimefon in plants
    and soil. Pflanzenschutz-Nachrichten Bayer 30, 1.

    Steffens, W., Führ, F. - Versuche zur Retranslokation von Triadimefon.
    Kernforschung sanlage Jülich, Arbeitagruppe Radioagronomie,
    unpublished report ARA 4/76. (1976).

    Steffens, W., Wieneke, J,. - Bilanzversuche mit dem 14C-markierten
    Fungizid  Triadimefon (MEB 6447) nach Spritzbehandlung von
    Sommergerste in Lysimetern mit ungesförten Bodenprofilen, Verbleib in
    der behandelten Pflanze, Verlagerung im Boden und Aufnahme durch
    Folgefrüchte. Kernforschungsanlage Jülich, Arbeitsgruppe
    Radioagronomie, unpublished report ARA 4/77, September. (1977).

    Takase, I., Hasebe, K. - Photolysis of Triadimefon in Upland Soils.
    Nitokuno Report  No. 1093, (RA), March 2, 1979.

    Takase, I., Yoshimoto, Y. - Degradation of Triadimefon in Upland soils
    under laboratory and field conditions. Nitokuno Report No. 1091 (RA),
    December 11, 1978.

    Thornton, J.S. - A gas chromatographic method for Bayleton and its
    metabolite in apples.  Mobay Report No. 54 166, December 30, 1977.

    Thornton, J.S., Lloyd, C.M. - A gas chromatographic method for
    Bayleton and its metabolite in soil and water. Mobay Report No. 51
    231, January 31, 1977.

    Thornton, J.S., Hurley, J.B., Obrist, J.J. - Soil thin-layer mobility
    of Twenty-four pesticide chemicals. Mobay Report No. 51 0.16, December
    15, 1976.

    Vogeler, K.  BAYER AG, Pflanzenschutz-Anwendungstechnik, unpublished
    report. Verhalten von Triadimefon (MEB 6447) unter der Einwirkung von
    UV-Licht. RA 364, June 3, 1975.

    Der metabolismus von Triadimefon in gerste unter
    Gewttchshausbedlingungen und im Boden. RA 272, April 12, (1976a).

    Untersuchunge zur Wirkang von Triadimefon über die Gasphase gegen
    Echten Mehltau an Gerste. RA 662, August 16, (1976b).

    Bericht über die Metabolisierung von 14C-Triadimefon in
    Sommergerste und Boden sowie in Folgenpflanzen. RA 813, October 19,
    (1977a).

    Untersuchungen zur Unwandlung der reinen Diastereoisomeren A und B
    von KWG 0519 in das jeweils andere Isomere in Gerstenpflanzen und
    Boden. RA 871, November 14, (1977b).

    Adsorptionsisothermen von Tiadimenol in verschiedenen Böden. RA 496,
    July 3, 1978.

    Wilmes, R. - Versuche zum Photoabbau von MEB 6447, MEB 6449 und KWG
    0519. BAYER AG, Pflanzenschutz-PIQ, PF-Report No. 1266, August 7,
    1978.
    


    See Also:
       Toxicological Abbreviations
       Triadimefon (Pesticide residues in food: 1981 evaluations)
       Triadimefon (Pesticide residues in food: 1983 evaluations)
       Triadimefon (Pesticide residues in food: 1984 evaluations)
       Triadimefon (Pesticide residues in food: 1985 evaluations Part II Toxicology)