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)