PROPARGITE JMPR 1978 Explanation Propargite was evaluated in 1977 (FAO/WHO, 1978b), when a temporary ADI was allocated and a number of maximum residue limits were recommended. The compound is due for reevaluation in 1981, but some of the information recorded as desirable by the 1977 Meeting has been received and is reviewed in the following monograph addendum. IDENTITY The data given below supplement the information given in the 1977 evaluation. Synonym Proparigite Information on identity and properties Molecular weight: 350 Physical form: Light to dark brown viscous liquid Odor: Faint solvent odor. A strong odor of SO2 may mean that partial decomposition has occurred. Volatility: Low Specific gravity 25°C: 1.085 - 1.115 Flash point: 28°C (min.) Pensky Martens Stability: Between 0.5 and 1.0% propylene oxide is added to stabilize Omite Technical. Shows no degradation after 12 months storage. Water, max.%:Less than 0.1 Solubility: Water - about 0.5 mg/kg 25°C. Miscible with organic solvents such as acetone, benzene, ethanol heptane and methanol. Assay Method Infrared spectroscopy based on the propargyl absorption at 3.03 microns in comparison with a standard of known purity. Formulation OMITE - 4D 4% Dust OMITE - 3OW 30% Wettable Powder OMITE - 57E 57% Emulsifiable Concentrate OMITE - 6E 68% Emulsifiable Concentrate OMITE 75% Emulsifiable Concentrate RESIDUES IN FOOD AND THEIR EVALUATION USE PATTERN Propargite is a specific acaricide which, when used at recommended rates, is relatively safe to honey bees and many beneficial parasitic and predaceous insects. Predaceous mites will not be eliminated from treated areas and it can be successfully used in integrated control programmes. Pre-harvest treatments In countries other than the United States formulations are registered for use on apples, apricots, cherries, citrus, maize, cotton, grapes, hops, nectarines, peaches, pears, plums, prunes, raspberries, strawberries, tea, vegetables such as beans and cucumbers and ornamentals. Propargite has provided effective control of the following mite species: apple rust mite, Banks grass mite, brown mite, citrus red mite, citrus rust mite, clover mite, cyclamen mite, European red mite, McDaniel spider mite, Pacific spider mite, peach silver mite, six-spotted mite, strawberry spider mite, Texas citrus mite, two-spotted spider mite, Willamette mite. RESIDUES RESULTING FROM SUPERVISED TRIALS Residues in crops Residue data were available from Field Tests conducted in the Netherlands, South Africa, Canada and India. Results are summarized in Table 1. FATE OF RESIDUES In plants Propargite - 14C (Phenyl), formulated as Comite(R), was applied to defined areas in the upper surfaces of mature leaves on two Blue Lake Bush Bean plants (Wong et al., 1978). After seven days, 68% of the applied radioactivity was recovered from the treated area as propargite. no significant translocation of radioactivity to untreated areas of the treated leaf or to TABLE 1. Propargite residues from supervised trials Crop Country Application Residues, mg/kg, Days after application Apples Netherlands Omite 30W 0 7 14 21 Var. 1 0.79 0.79 0.84 0.78 Var. 2 0.73 0.82 0.60 0.93 S. Africa 0 2 6 13 20 Omite 30W 1.03 0.94 0.87 0.62 - Omite 57E 0.99 1.08 0.82 1.02 0.84 Ontario, Canada 0.61 lbs. ai/acre 14 MacIntosh 0.33 Spy 0.59 Golden Del. 0.59 0.54 lbs. ai/acre MacIntosh 0.43 Spy 0.20 Golden Del. 0.47 Tomatoes Netherlands Aerosol 0 3 1.21 1.23 S. Africa Omite 30W 0 3 7 14 21 28 1.11 1.29 1.44 0.35 0.43 0.30 Cucumbers Netherlands Aerosol 0 3 Site 1 0.32 0.18 Site 2 0.23 - Tea leaves Borbhetta, India Omite 57E 7 Manufactured 0.75 kg. ai/ha 0.5 0.5 TABLE 1. (Cont'd) Crop Country Application Residues, mg/kg, Days after application 0.5 1.5 kg. ai/ha 1.1 1.0 0.97 Sun dried 0.75 kg. ai/ha 0.7 0.5 0.5 1.5 kg. ai/ha 0.9 0.9 0.9 Manufactured Cinchona District, 1.50 kg. ai/ha 7 S. India 2.04 2.04 2.24 Sun dried 1.52 1.24 1.16 Manufactured Assam, N. India 0.75 kg ai/ha 7 0.50 0.46 0.52 1.50 kg ai/ha 1.14 1.00 0.97 Sun dried 0.75 kg ai/ha 0.66 0.45 0.46 1.50 kg ai/ha 0.89 0.90 0.90 TABLE 1. (Cont'd) Crop Country Application Residues, mg/kg, Days after application Manufactured Madras, India 0.75 kg ai/ha 0 7 14 28 67 4 <0.1 <0.1 61 3.8 <0.1 48 4.2 <0.1 Sun dried 161 2.6 0.2 <0.1 174 1.1 <0.1 178 1.8 <0.1 Manufactured Coimbatore District 0.31 kg ai/ha 7 14 <0.1 0.2 Sun dried 0.3 <0.1 untreated portions of the whole plant was observed by autoradiography (sensitivity: 0.1% of applied 14C). Thus, residues of propargite and its degradation products found in beans are unlikely to result from translocation. In another experiment, two Blue Lake Bush Bean plants were treated with two applications of propargite - 14C, formulated as Comite(R), according to field usage. After harvest 1.8% of the applied radioactivity remained on the beans (5.6 mg/kg calculated as propargite). The majority (60.4%) of the radioactivity associated with the beans was characterized as propargite - 14C and the remainder consisted mainly of polar material (29.3%) and unextractable residues (5.5%). APPRAISAL Propargite in a specific acaricide with registered uses on a wide variety of agricultural crops in many countries. It was first evaluated by the Joint Meeting in 1977. In response to questions arising from that meeting information was received and evaluated on residues resulting from supervised trials in countries other than the U.S.A. and on the translocation and fate of residues in plants. Summary data on the results of field trials on apples were received from Canada, the Netherlands and South Africa, on tomatoes from the Netherlands and South Africa and on cucumbers from the Netherlands. These data indicated that it would be unlikely for residues to exceed 2 mg/kg on apples, 2 mg/kg on tomatoes, or 0.5 mg/kg on cucumbers. Detailed data were received an field trials on tea in various regions in India. Since it is common practice in tea culture to pick leaves repeatedly from the same bush at a desired stage of growth, it is possible to have some leaves harvested as soon as 1 day after treatment, especially if repeated treatments are required. However, in the absence of information on the need for repeated treatments, it was assumed that control over the pre-harvest interval could be exercised by growers and an interval of 7 days was selected on which to base recommendations. Data on residues on manufactured tea at a pre-harvest interval of 7 days show that values of 5 mg/kg would not be exceeded. Experiments with 14C-labelled propargite, formulated as COMITE(R), applied either to defined areas of Blue Lake Bush Bean leaves or according to field usage indicated that no significant translocation of propargite or its degradation products took place and that the residue on beans consisted mainly (60.4%) of propargite, the remainder being polar material (29.3%) and unextractables (5.5%). RECOMMENDATIONS The following temporary maximum residue limits are recommended. Those for tea, tomatoes and cucumbers are new. Those for apples, figs and peers are amended on the basis of new data and to comply with the usual manner of expressing limits. Commodity Limit, mg/kg Tea (dried, manufactured) 5 Apples 2 Figs 2 Pears 2 Tomatoes 2 Cucumbers 0.5 FURTHER WORK OR INFORMATION Desirable 1. Additional data from supervised trials in countries other than U.S.A. 2. Information on the occurrence of residues on commodities in commerce. REFERENCES Uniroyal, Technical Data Sheet on OMITE(R) Acaricide Uniroyal, Residue Data obtained from Field Tests conducted (1978) outside the USA. Wong, D.T.L., Tortora, N.J., Fuller G.B. and Cardona, R.A. (1978) Translocation and Fate of Propargite - 14C on Blue Lake Bush Beans. Report on Project No. 7834, Uniroyal Chemical.
See Also: Toxicological Abbreviations Propargite (Pesticide residues in food: 1977 evaluations) Propargite (Pesticide residues in food: 1979 evaluations) Propargite (Pesticide residues in food: 1980 evaluations) Propargite (Pesticide residues in food: 1982 evaluations) Propargite (JMPR Evaluations 1999 Part II Toxicological)