Residues Of Propargite Research Articles

Farm to fork strategy for evaluating the qualitative and quantitative health risks to the Nepalese population associated with pesticide residues in apple and banana

Studies of pesticide use on commercial fruits are limited in Nepal. We surveyed the experiences and opinions of banana farmers in Nepal and monitored pesticide residues in apples and bananas. We monitored the residual status and associated health risks of 51 multi-group pesticides using Liquid Chromatography Triple Quadrupole Mass Spectrometry. Apple and banana samples were collected from different districts, farms, markets, and seller categories (our farm to fork survey). We found a significant bivariate positive correlation between farmers’ knowledge of pesticide negative effects and safety-promoting behavior among farmers. Residues of tebuconazole, difenoconazole, propargite and imidacloprid were most frequently detected. Of all the detected pesticides, propargite showed the highest concentration in apples, exceeding regulatory maximum residue limits (MRLs) in 24% of the samples. Epoxiconazole, tebuconazole, imidacloprid, quinalphos, fenpropathrin and bifenthrin in apples, and metalaxyl and imidacloprid in bananas also crossed their MRLs. Dietary exposure to pesticides among children and adults was estimated based on a hazard quotient and hazard index by using lower-bound and upper-bound approaches. Our results indicated that children consuming apples with residues of propargite are exposed to the greatest pesticide hazard.

Screening for suitable chemical acaricides against two-spotted spider mites, Tetranychus urticae, on greenhouse strawberries in China

Effective and safe acaricides based on scientific data are needed for that no chemical acaricides has been registered for the control of two-spotted spider mite in strawberry crops in China. To identify suitable acaricides, the efficacy, persistence, and toxicity of eight acaricides (hexythiazox, fenpyroximate, chlorfenapyr, propargite, etoxazole, bifenazate, spirodiclofen, and pyridaben) on greenhouse strawberries were tested. The eight acaricides were ranked, from highest average efficacy at the recommended dosage to lowest, as follows: etoxazole > bifenazate > fenpyroximate > propargite > spirodiclofen > pyridaben > hexythiazox> chlorfenapyr. The average recoveries of the eight acaricides at the spiking levels of 0.05 and 0.5 mg/L ranged from 72.4% to 108.1% (relative standard deviation, 1.3–8.8%). The concentrations of hexythiazox, fenpyroximate, etoxazole, bifenazate, spirodiclofen, and pyridaben at 5 days after application were lower than the maximum residue limits (MRLs) specified by China, the European Union (EU), the Codex Alimentarius Commission, and Japan, but those of chlorfenapyr and propargite residues were 8.8 and 1.9 times higher than the MRLs in the EU. Only propargite posed a high chronic dietary risk to humans. Pyridaben and chlorfenapyr showed unacceptable ecotoxicology risks for honeybees (hazard quotient values of > 50). The recommended acaricides to control spider mites in greenhouse-grown strawberry crops are etoxazole, bifenazate, fenpyroximate, spirodiclofen, and hexythiazox based on the efficacy, persistence and toxicity.

Setting of maximum residue limits for propargite in citrus fruits and tea.

In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS) Italy received an application from Arysta LifeScience Great Britain Ltd to set maximum residue levels (MRL) for the active substance propargite in imported citrus fruits and tea. Italy drafted an evaluation report in accordance with Article 8 of Regulation (EC) No 396/2005, which was submitted to the European Commission and forwarded to EFSA. According to EFSA, the data are sufficient to derive a MRL proposal of 4 mg/kg for oranges only, as the extrapolation to the whole group is not supported by the EU rules. Based on the residue trials, an MRL of 50 mg/kg for tea could be derived. However, a risk manager decision is required whether the setting of a MRL of 50 mg/kg for tea is acceptable since the MRL reported to be into force in India is 10 mg/kg. Adequate analytical enforcement methods are available to control the residues of propargite on the commodities under consideration. Since the enforcement method of analysis is not enantioselective, residues are determined as the sum of any possible isomer ratio of the active substance propargite. EFSA concluded that the use of propargite on oranges and tea as reported in the countries of origin will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk. However, it should be noted that the risk assessment is affected by uncertainties linked to the toxicological profile and the reliability of results for some of the metabolites included in the residue definition and it is applicable to the technical propargite with the isomer ratio 99:1 under assessment.

Residues of Propargite in Tea

Propargite is an acaricide extensively used in India for controlling the populations of the red spider mite (RSM) infesting tea. Field experiments were conducted at two places in Tamil Nadu (India) during the dry season to determine the residues of propargite in black tea. Residues were quantified at different harvest intervals of '0' (3 hr), 1st, 3rd, 5th, 7th, 10th and 14th day after acaricide application. Persistence, dissipation pattern, half-life value and safe harvest interval of the acaricide in tea were calculated. Residues of propargite dissipated exponentially after application at both the locations and reached below the CODEX MRL of 5 mg/kg on the 7th day. Regression lines drawn on propargite showed that like other acaricides it followed the first order dissipation kinetics. Half-life values varied from 1.63 to 1.92 days for propargite and a safety harvest interval of 7 days is suggested for the tea crop.

Effects of processing techniques on propargite residues in orange juice and its by-products

Effects of processing techniques on propargite residues in orange juice and its by-products

Persistence of Propargite on Okra Under Subtropical Conditions at Ludhiana, Punjab, India

Residues of propargite were estimated in okra fruits by high performance liquid chromatography following single application of Omite 57 EC @570 and 1,140 g a.i./ha. Residues of propargite were confirmed by high performance thin layer chromatography. The average initial deposits of propargite were observed to be 1.36 and 3.32 mg/kg, respectively, which were below its maximum residue limit of 2 mg/kg. The residue levels of propargite dissipated below its limit of quantification of 0.02 mg/kg after 7 days at single dose and after 10 days at double dose. The half-life values (T ₁(/)₂) of propargite were worked out to be 0.79 and 0.73 days, respectively, at recommended and double the recommended dosages.

Dissipation Kinetics of Propargite in Brinjal Fruits Under Subtropical Conditions of Punjab, India

Residues of propargite were estimated in brinjal fruits by High Performance Liquid Chromatography (HPLC) following single application of Omite 57 EC @ 570 and 1140 g a.i./ha. The average initial deposits of propargite were observed to be 0.51 and 0.92 mg/kg, respectively, which were below its maximum residue limit (MRL) of 2 mg/kg. The residue levels of propargite dissipated below limit of quantification (LOQ) of 0.02 mg/kg after 10 days at both the dosages. The half-life values (T(1/2)) of propargite were worked out to be 3.07 and 3.54 days, respectively, at recommended and double the recommended dosages. A waiting period of one day has been suggested for the safe consumption of brinjal fruits to avoid any health hazards.

Operational and Biological Factors Influencing Responses of Spider Mites (Acari: Tetranychidae) to Propargite by Using the Petri Dish-Potter Tower Method

A series of laboratory bioassays was done to determine the effects of various operational and biological factors on the responses of adult female twospotted spider mite, Tetranychus urticae Koch, and European red mite, Panonychus ulmi (Koch), to propargite when using the Petri dish—Potter tower method. The spray volume (1—5 ml) used to treat the petri dishes significantly influenced the responses of both species to propargite residues: a 5-ml spray volume was 6.7- and 4.7-fold more toxic than a 1-ml spray volume at the LC50 to twospotted spider mite and European red mite, respectively.To test the effectiveness of propargite residues over time, mites were exposed at intervals to treated petri dishes that were stored for up to 30 d at 4 ± 1oC. The toxicity of propargite remained constant throughout this period. When mites were retained in petri dishes in a manner that prevented contact with residues, no mortality of mites caused by the vapor action of propargite was detected at 23 and 30oC. However, the toxicity of propargite to mites in contact with residues increased 113- and 522-fold at the LC50 between 10 and 30oC for twospotted spider mite and European red mite, respectively. The age of adult females also influenced the response to propargite residues: 7-d-old twospotted spider mite females were 1.9-fold more tolerant than 1-d-old females at the LC50.The relevance of these findings to miticide bioassays using this method is discussed.

Study of Procymidone and Propargite Residue Levels Resulting from Application to Greenhouse Tomatoes

Levels of procymidone and propargite residues were studied in an experiment in greenhouse tomatoes. The pesticides were applied according to recommended application procedures in Greece. Tomatoes received six sprayings with procymidone, at 10-day intervals, at rate of application 62.5 g of ai/100 L and a single spraying with propargite, at rate of 60 g of ai/100 L. In separate experimental plots double doses were applied, according to the same scheme. Residues were determined with a simple gas chromatographic method; the recovery of procymidone from tomatoes was 85-104% and of propargite 94-101%; the limits of determination were 0.005 mg/kg for procymidone and 0.01 mg/kg for propargite

RESIDUAL TOXICITY OF DICOFOL, FORMETANATE HCl, PROPARGITE, HEXYTHIAZOX, AND CLOFENTEZINE TO EUROPEAN RED MITE ON PEACH

AbstractThe persistence of toxic effects of the contact acaricides dicofol, propargite, and formetanate HCl and the ovicides clofentezine and hexythiazox to the European red mite, Panonychus ulmi (Koch), were tested by bioassays of disks cut from treated peach foliage. Effects of dicofol were more persistent than propargite or formetanate HCl to susceptible mites. Mortality on dicofol-treated foliage was >50% for more than 15 days. Propargite killed >50% of females for 10 days after application, whereas the toxicity of formetanate HCl deposits declined rapidly after 7 days. Mortality of dicofol-resistant mites was less than for susceptible mites. However, resistant mites were affected (>50% killed) by dicofol residues up to 7 days old. The toxic effects of the ovicides clofentezine and hexythiazox persisted for at least 30 days and at the rates tested were approximately equally toxic.Formetanate HCl and propargite residues were less persistent (half-life 8–9 days) than the other compounds. Dicofol residues had a half-life of about 15 days but approximately 10% of residues persisted for 65 days. Residues of clofentezine and hexythiazox declined more gradually (half-life = 15–20 days) than other compounds and persisted at approximately 10% of initial residues after 65 days.