Sponsored jointly by FAO and WHO


    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



    Pirimiphos-methyl was evaluated in 1974, 1976 and 1977 and an ADI was
    estimated and MRLs in a range of commodities were recommended.  The
    11th Session of the Codex Committee on Pesticide Residues requested
    that the meeting should consider pirimiphos-methyl residues in kiwi



    Kiwi fruit (Actinidia chinensis) is now the second largest
    horticultural product exported from New Zealand, the value being in
    excess of U.S. $20 million annually.  The fruit is subject to attack
    by a number of pests and diseases and to meet plant health
    requirements of countries importing New Zealand produced kiwi fruit,
    it is necessary to spray regularly.  Because of the hairy nature of
    the skin, spray residues are retained on the fruit more than if the
    skin was smooth.  Trials data have shown that 90% of the pesticide
    residues remain on the skin.  The skin, being hairy, is relatively
    unpalatable and normally discarded.

    Pirimiphos-methyl has been under development for control of greedy
    scale, Hemiberlasia rapax on kiwi fruit.  The rate of application
    ranges from 750-1250 g/ha with the minimum pre-harvest withholding
    interval being 14 days.

    Two sets of residue data were available both reflecting the use of EC
    formulations.  In the first set of work (O'Kane 1977),
    pirimiphos-methyl was sprayed at 750 g/ha, with the results shown in
    Table 1.  In the second set of data (Cheong 1979), pirimiphos-methyl
    was sprayed "high volume" using approximately 2500 l/ha of a 0.0475%
    ai solution with the results as shown in Table 2.  The analyses were
    conducted by gas chromatography as reviewed at the 1974 and 1976

    The results quoted relate to pirimiphos-methyl itself.  No residues of
    the phosphorus-oxygen analogue were recorded, which is consistent with
    the results of the earlier work on other crops reviewed in 1976.

    Table 1.  Pirimiphos-Methyl Residues in Kiwi fruit sprayed 6 times at
              14-21 days intervals at 750 g ai/ha
              (New Zealand, 1976 - 1977)

    Interval Between       Residues of pirimiphos-methyl (mg/kg)
    Last Application                                            
    and Harvest         Edible pulp       skin        whole fruit

     0                     0.27          28,32            3.9
     7                     0.12           38              2.5
    14                     0.10          12,12            2.0
    21                     0.10           8.5             1.2
    28                     0.05            4              0.7

    (O'Kane, 1977)

        Table 2.  Pirimiphos-Methyl Residues in Kiwi Fruit*
              New Zealand, 1979

    Interval Between                                                            Mean
    Last Application                     Lowest Residue     Highest Residue     Residue
    and Harvest          Crop - Part       Determined          Determined       Determined
    (days)                Analysed          (mg/kg)             (mg/kg)         (mg/kg)

         7               Whole Fruit          0.57                3.1            1.8 (3)
         14                   "               0.60                2.3            1.6 (3)
         28                   "               0.26                1.0            0.65 (2)
         42-43                "              <0.05                1.1            0.45 (3)
         >56                  "              <0.05                0.15           0.09 (7)

         14                 Skin              5.3                10              8.1 (3)
         28                   "               1.6                 3.9            2.8 (2)

         14-28           Edible pulp         <0.05               <0.06          <0.06 (5)
    (Cheong, 1979)

    Figures in parentheses are the number of results upon which the means are based.

    * Sprayed at approximately 2500 litres per ha. with 0.0475% a.i.


    Pirimiphos-methyl has been under development for the control of 
    greedy scale on kiwi fruit in New Zealand.  Two sets of residue 
    data reflecting different methods of application during two 
    separate seasons have provided the basis for recommending maximum 
    residue limits.  These data reveal that over 90% of the residue 
    is retained in inedible skin, there being no significant residue 
    in the edible pulp. The studies have confirmed that the residues 
    consist of the parent compound alone.


    The following maximum residue limit is recommended.  They refer 
    to pirimiphos-methyl alone.

    Commodity      Limit mg/kg     Pre-harvest interval on which
                                   recommendations are based
    Kiwi fruit         2                     14-21


    Cheong, H.  Analysis of pirimiphos-methyl in kiwi fruit ICI (NZ) 
    Ltd.  (1979) Unpublished residue data.

    O'Kane.  ACTELLIC: Kiwi fruit ICI (NZ) Ltd. (1977) Unpublished 
    residue data.

    See Also:
       Toxicological Abbreviations
       Pirimiphos-methyl (WHO Pesticide Residues Series 4)
       Pirimiphos-methyl (Pesticide residues in food: 1976 evaluations)
       Pirimiphos-methyl (Pesticide residues in food: 1977 evaluations)
       Pirimiphos-methyl (Pesticide residues in food: 1983 evaluations)
       Pirimiphos-methyl (Pesticide residues in food: 1992 evaluations Part II Toxicology)