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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



    DIAZINON

    Explanation

    Diazinon has been evaluated on a number of previous occasions.  An
    ADI of 0.002 mg/kg has been established and MRLs have been
    recommended for diazinon in a wide range of food commodities.

    The New Zealand Ministry of Agriculture requested the meeting to
    consider diazinon residues in kiwi fruit with a view to
    recommending a maximum residue limit.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    Diazinon is used, in combination with carbaryl, as an alternative
    to phosmet.  Four sprayings would normally be applied,
    mid-December, January, February and March using 1.125 kg/ha at each
    application with a maximum of 4.5 kg/ha in any one season.  With
    kiwi fruit being picked in May, the time between the last
    application and picking is at least 30 days.  The major pest
    against which diazinon is used is greedy scale (Hemiberlesia
    rapax).

    Studies published by Love and Ferguson (1977) indicate that
    diazinon residues may be determined by gas chromatography on kiwi
    fruit with a recovery of 100-110% at 0.3-1.7 mg/kg.  Their results
    include figures for rates of diminution of residue levels between
    final spraying and harvest.

    Table 1 summarized the results from a monitoring program conducted
    by the New Zealand Ministry of Agriculture and Fisheries between
    1973 and 1978.  Of the 90 samples examined, the highest residue
    detected was 0.29 mg/kg.

    In a trial carried out in 1973, three applications of diazinon 50%
    wettable powder were made at monthly intervals, at 3 rates, to a
    trial plantation of kiwi fruit.  Residues of diazinon were
    determined and are expressed on a whole fruit basis in Table 2. 
    These data explain why the New Zealand authorities chose to
    restrict the spray program to a maximum of 4.5 kg/ha for the season
    and to enforce a time interval between the last spray and harvest
    of 30 days.

    Table 1.  Diazinon Residues on Kiwi fruit - 
    Results from Grower Use

                                    
    Year       Range           No.
                                    

    1973       <0.01           15
               0.01-0.05       11
               0.05-0.1        5
               >0.1            1
                                  
                               32

    1974       <0.01           13
               0.01-0.05       32
               0.05-0.1        3
               >0.1*           0
                                  
                               48

    1978       <0.01           4
               0.01-0.05       4
               0.05-0.1        1
               >0.1*           1
                                  
                               10
                                    

    * Highest residue 0.29 mg/kg



        Table 2.  Diazinon Residues in Kiwi fruit

                                                                                                                           
    Application rate
     (kg a.i./ha per    Replicate     Prespray
      application)                    day - 1
                                                       1       2       5      8       11       15      21      28      35
                                                                                                                           

          2.9               1           0.09          1.3     1.3     1.2    0.61    0.48     0.51    0.24    0.27      -
          2.0               2           0.09          1.5     0.8     0.8    0.91    0.56     0.46    0.35    0.35      -
          4.3               1           0.09          3.0     1.9     1.3    0.92    0.74     0.38    0.38    0.29    0.12
          4.3               2           0.13          2.4     1.5     1.2    0.54    0.61     0.62    0.28    0.23    0.16
          5.7               1           0.16          4.6     2.7     1.9    1.3     1.2      0.66    0.36    0.40    0.21
          5.7               2           0.11          1.2     1.9     1.3    0.53    0.41     0.43    0.24    0.27    0.19
                                                                                                                           
    


    APPRAISAL

    Diazinon is used along with other insecticides for the control of
    greedy scale on kiwi fruit in New Zealand.

    The residue data from supervised trials and from monitoring the use of
    diazinon by growers give a clear picture of the level and fate of
    diazinon residues on kiwi fruit.  These data reveal that over 90% of
    the residue is retained in inedible skin, there being no significant
    residue in the edible pulp.  The residue consists of the parent
    compound alone.

    RECOMMENDATION

    The following maximum residue limit for diazinon are recommended:

                                                                 
    Commodity      Limit (mg/kg)    Preharvest interval on which
                                    recommendations are based
                                                                 

    Kiwi fruit     0.5              30 days
                                                                 

    REFERENCES

    New Zealand.  Submission from the New Zealand Ministry of Agriculture
    and Fisheries, Wellington, New Zealand to FAO, 22 September 1978.

    Love, J.L. and Ferguson, A.M. - Pesticide residues and Greedy Scale
    control on Kiwi fruit. New Zealand journal of Agricultural Research
    20: 95-103.
    


    See Also:
       Toxicological Abbreviations
       Diazinon (EHC 198, 1998)
       Diazinon (ICSC)
       Diazinon (FAO Meeting Report PL/1965/10/1)
       Diazinon (FAO/PL:CP/15)
       Diazinon (FAO/PL:1967/M/11/1)
       Diazinon (FAO/PL:1968/M/9/1)
       Diazinon (AGP:1970/M/12/1)
       Diazinon (WHO Pesticide Residues Series 5)
       Diazinon (Pesticide residues in food: 1993 evaluations Part II Toxicology)
       Diazinon (JMPR Evaluations 2001 Part II Toxicological)