Residue levels and dietary risk assessment of fluopimomide, pyraclostrobin and its metabolite BF-500–3 in garlic ecosystems under field conditions

To evaluate the residue levels of fluopimomide, pyraclostrobin and its metabolite BF-500–3 in garlic ecosystems, supervised garlic field trials with a commercial formulation (pyraclostrobin·fluopimomide 30% suspension concentrate (SC)) were conducted in six regions of China according to the Good Agricultural Practices (GAP). The residues of fluopimomide, pyraclostrobin and BF-500–3 in field samples were determined using a QuEChERS method combined with high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS). The average recoveries of all target compounds were 76–94% with relative standard deviations (RSDs) of 1.0–14.5% and limits of quantitation (LOQs) of 0.002 mg/kg. At the recommended pre-harvest interval (PHI, 10 days), the residues of fluopimomide, pyraclostrobin and BF-500–3 were below 0.16, 0.77 and 0.12 mg/kg in garlic chive; below 0.027, 0.22 and 0.002 mg/kg in garlic scape; and below 0.002, 0.002 and 0.002 mg/kg in garlic, respectively. Dietary intake risks were calculated using risk quotients (RQs) based on field residual data, toxicological data and dietary patterns. The chronic dietary risk quotients (RQc) of pyraclostrobin and fluopimomide were 48.42% and 0.36%, respectively. The acute dietary risk quotients (RQa) of pyraclostrobin in garlic were 0.06–0.15%. These results indicated a low dietary risk for consumers. This study could provide scientific guidance for the application of pyraclostrobin and fluopimomide in garlic.


Introduction
Garlic (Allium sativum L.), a species in the onion genus Allium, is widely cultivated in many countries and regions of the world. China is the largest garlic producer in the world with an annual output of approximately 20 million tons, which accounts for over 81% of global garlic output . The garlic plant has three different edible parts: garlic chive (the green immature seedling of the garlic plant), garlic scape (the immature flower stalks of the garlic plant) and garlic (the garlic plant bulb). Garlic is rich in proteins, lipids, minerals and sugars and can prevent many diseases, such as hyperglycemia, cancer and cardiovascular disease (Ansary et al. 2020). Garlic is vulnerable to diseases during planting, among which garlic blight is a common fungal disease. The application of fungicides to garlic is a widespread and effective method for controlling garlic blight. However, improper use of pesticides may result in a high level of pesticide residue in crops, which will cause serious pollution to the environment and bring undesired health risks to consumers. Currently, a new commercial formulation, 30% suspension concentrate (SC, 25% pyraclostrobin + 5% fluopimomide), is being registered to control garlic blight in China. Therefore, it is necessary to carry out supervised field trials to assess pesticide residues and dietary risks before this formulation is registered. Pyraclostrobin,-1H-pyrazol-3-yl]-oxymethyl]phenyl)-N-methoxycarbamate (IUPAC), is a broad-spectrum strobilurin fungicide (FAO  . Pyraclostrobin inhibits mitochondrial respiration by blocking electron transport in the respiratory chain, which in turn leads to serious disruption of important cellular biochemical processes and cessation of fungal growth (FAO 2003). The main metabolite of pyraclostrobin is methyl-N-(2[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxymethyl]phenyl) carbamate (BF-500-3) because the methoxy group on the tolyl-methoxycarbamate moiety is readily lost (FAO 2004). BF-500-3 is similar to pyraclostrobin in chemical structure, so it is thought to have toxicity similar to that of the parent pyraclostrobin (You et al. 2015). Pyraclostrobin and its metabolite BF-500-3 constituted the main fractions of the residue from most plant samples after the application of pyraclostrobin, according to the report of the Joint FAO/ WHO Meeting on Pesticide Residues (JMPR). Fluopimomide, N- [[3-chloro-5-(trifluoromethyl)pyridin-2-yl]methyl]-2,3,5,6-tetrafluoro-4-methoxybenzamide (IUPAC), is a new fluorinated benzamide fungicide with independent intellectual property rights in China. It was first synthesized in 2010 by Shandong Sino-Agri Union Biotechnology Co., Ltd. (Shandong, China). Fluopimomide is a broad-spectrum fungicide that acts on the respiratory chain of fungal mitochondria and inhibits the activity of succinate dehydrogenase (Lewis et al. 2016). Fluopimomide exhibits strong control of many fungal diseases, such as phytophthora capsici, cotton blight, rice sheath blight and potato late blight (PubChem 2022). The chemical structures of the three compounds of interest were shown in Fig. 1.
Various residue studies have reported the parent pyraclostrobin in different matrices, including strawberry (Malhat et al. 2019), cucumber (Zhao et al. 2020), oriental melon (Kabir et al. 2017), apple (Podbielska et al. 2018, raspberry (Lozowicka et al. 2012), grape (Wang et al. 2018b) and citrus . However, the metabolite BF-500-3 was ignored in those studies. Only a few articles have reported the residues of total pyraclostrobin (sum of pyraclostrobin and BF-500-3) in corn (You et al. 2012), pepper (Gao et al. 2019), litchi (Wang et al. 2018a), cucumber  and longan (Yanping et al. 2020), while these articles studied only the residue behavior of the compounds and did not assess dietary risk. Fluopimomide is a newly invented pesticide in China, and a few studies have reported residues and risk assessments for fluopimomide. Residue analytical methods of fluopimomide in potato (Yizhi et al. 2017) and grape (Xiaoxue et al. 2019), residue behavior in cucumber , residue behavior and dietary risk in taro (Yang et al. 2021) have been reported. To the best of our knowledge, no method for the simultaneous determination of pyraclostrobin, BF-500-3 and fluopimomide in garlic has been developed. Moreover, no data on residue behavior or a dietary risk assessment of pyraclostrobin (sum of pyraclostrobin and BF-500-3) and fluopimomide have been published for applications in garlic field ecosystems.
The objectives of this study were (1) to establish a simple, sensitive and efficient method for simultaneously determining pyraclostrobin, BF-500-3 and fluopimomide in garlic chive, garlic scape and garlic based on the QuEChERS procedure combined with high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS); (2) to investigate the residues of pyraclostrobin, BF-500-3 and fluopimomide in garlic samples sprayed with 30% SC in six representative regions of China according to the Good Agricultural Practices (GAP); and (3) to assess the dietary intake risk of pyraclostrobin and fluopimomide. The results will provide scientific guideline for the application of this commercial formulation in garlic fields.

Field trials
Supervised field trials were designed according to NY/T 788-2018 (Guidelines for Testing Pesticide Residues in Crops issued by the Ministry of Agriculture of China), and the trials were carried out during 2021 in six representative garlic-growing regions of China. The main GAP conditions included the recommended dose of 90-135 g a.i./ ha, 2-3 times of application at intervals of 7-14 days and a recommended pre-harvest interval (PHI) of 10 days. The climate description, crop information, geographic location and soil information of different trial sites were shown in Table S1.
The field trials of garlic chive, garlic scape and garlic were carried out separately in individual trial plots. Each trial plot comprised a control plot and a treatment plot, both with an area of 50 m 2 separated by irrigation channels. Thirty percent SC was sprayed three times at intervals of 7 days in the early stages of garlic blight, and the doses were 135 g a.i./ha. The blank control plot was sprayed with water. The time of application was shown in Table S2. The recommended PHI for garlic was 10 days. Samples were randomly collected from each plot at different time intervals (10 and 14 days). The purpose of setting the intervals to harvest of 14 days was to assist in determining the optimal PHI.
For three of the six regions, additional intervals to harvest were set to determine the initial deposits (2 h after spraying) and the residues near the PHI to verify the rationality of the recommended PHI. Samples were collected at 0 (2 h), 5, 7, 10, 14 and 21 days after the last application in these three regions. Since the harvest time of garlic scape is very short, two trial plots were set for garlic scape in these three regions. For one, the first application was 35 days before the garlic scape harvest time, and samples were collected at 10, 14 and 21 days after the last application. In the other plot, the first application was 21 days before the garlic scape harvest time, and samples were collected at 0 (2 h), 5 and 7 days after the last application. The design of the field trials was shown in Table S3. Disease-free samples exhibiting normal growth were randomly collected with a sampling number of not less than 12 points and quantity of at least 2 kg. Two independent samples were obtained from each treatment plot, and each sample was divided into 150 g samples by the four-point method. The samples were kept deep-frozen (− 18 °C) after thorough mixing.

Extraction and purification of samples
Each sample was homogenized with a high-speed blender. Homogenized samples (5.00 g) were weighed into a 50-mL centrifuge tube and extracted with 10 mL of MeCN. Then, the mixture was vortexed for 3 min using a vortex mixer, and 4 g of MgSO 4 and 1 g of NaCl were added. The mixtures were vortexed for 3 min using a vortex mixer and then centrifuged at 4000 rpm for 3 min. One milliliter of the supernatant was transferred into a 2-mL centrifuge tube containing 200 mg of MgSO 4 , 40 mg of PSA and GCB (10 mg for garlic chive, 5 mg for garlic scape, 0 mg for garlic). The tube was shaken for 3 min and centrifuged at 10,000 rpm for 3 min. The supernatant was filtered into an autosampler via a 0.22µm syringe filter and analyzed by HPLC-MS/MS.

HPLC-MS/MS analyses
The HPLC-MS/MS system used for analyzing pyraclostrobin, BF-500-3 and fluopimomide consisted of an Agilent 1260 Infinity HPLC system (Agilent Technologies, USA) coupled to a 6460 triple-quadrupole mass spectrometer equipped with an electrospray ionization source (Agilent Technologies, USA). Chromatographic separation of the analytes was performed on an Agilent SB-C18 analytical column (3.0 mm × 50 mm, 2.7 μm).
The mobile phase consisted of MeCN (A) and 0.1% formic acid aqueous solution (B). The flow rate was 0.4 mL/min, and the injection volume was 5 µL. The following gradient elution program was applied: 50% A at 0 min, 90% A at 0.8 min, 90% A at 1.2 min and 50% A at 1.21 min. The total running time was 5.5 min, and the column temperature was set at 25 °C.
Determination of the target compounds was carried out on a tandem MS (MS/MS) platform. Multiple reaction monitoring (MRM) mode using positive electrospray ionization (ESI +) was used for qualitative and quantitative analysis of the target compounds. The MS parameters were as follows: capillary voltage, + 3.5 kV; collision gas, N 2 ; drying gas temperature, 300 °C; drying gas flow, 11 L/min; and nebulizer, 45 psi. The MS/MS parameters were shown in Table S4. Data acquisition and processing were performed with MassHunter B.08.02 (Agilent Technologies, USA) software.

Method validation
Recovery experiments were conducted to investigate the method's trueness at four spiked levels (0.002, 0.01, 0.1 and 2 mg/kg) for the three target compounds. There were 5 duplicates for each spiked level, and the precision of the method was expressed in terms of the relative standard deviation (RSD). Three recovery experiments were conducted on three different days to assess the reproducibility. The limit of detection (LOD) was estimated as 3 times the signal-tonoise (S/N) ratio, and the limit of quantification (LOQ) was the lowest spiked level. The linearity was assessed using the correlation coefficient (r) of 6-point (0.001, 0.005, 0.05, 0.1, 0.5 and 1 mg/L) matrix-matched calibration curves. The matrix effect (ME) was calculated by Eq. (1).

ME
ME was calculated as follows: Positive and negative MEs indicated enhancement and suppression, respectively, of the signal by the matrix. When the ME is in the range of − 20 to 20%, there is a soft matrix effect. When the ME is in the range of 20 to 50% or − 50 to − 20%, there is a medium matrix effect, while a strong matrix effect is assigned for MEs < − 50% or > 50% (Gomez-Almenar and Garcia-Mesa 2015).
Total residues of pyraclostrobin The definition of dietary risk assessment of pyraclostrobin is the sum of pyraclostrobin and its metabolite BF-500-3, expressed as pyraclostrobin. The total residues of pyraclostrobin were calculated with the following equation: where C sum represents the total residue concentration of pyraclostrobin; C pyraclostrobin and C BF-500-3 are the (1) Matrix effect = slope of calibration curve in matric slope of calibration curve in solvent − 1 × 100% (2) C sum = C pyraclostrobin + C BF−500−3 × M pyraclostrobin ∕M BF−500−3 concentrations of the parent pyraclostrobin and the metabolite BF-500-3, respectively; and M pyraclostrobin and M BF-500-3 are the molecular weights of pyraclostrobin (387.82) and BF-500-3 (357.80), respectively. If the residue of BF-500-3 was lower than the LOQ, the LOQ was directly used, and the total residue of pyraclostrobin was calculated directly from the sum of the concentrations of both compounds using the LOQ.
Dietary intake risk assessment. The field residual data, toxicological data and dietary patterns were considered to calculate dietary intake risks. The dietary intake risk of pyraclostrobin and fluopimomide residues was assessed by using the risk quotient (RQ) method (Jiang et al. 2020). When the RQ was less than 100%, the risk was considered acceptable. If the RQ was higher than 100%, it indicated an unacceptable risk, and the higher the value was, the higher the exposure risk.
The chronic dietary intake risk quotient (RQc) was calculated as follows (Shi et al. 2016): where NEDI is the national estimated daily intake, Σ represents the sum of the NEDIs of pyraclostrobin or fluopimomide in all registered crops in China, STMRi (mg/ kg) is the supervised trials median residual value, Fi (kg) is the daily consumption of one crop, ADI (mg/kg bw) is the acceptable daily intake and bw (kg) is the average weight of a Chinese adult (63 kg). Fi and bw were obtained from the Report on Nutrition and Health Status of Chinese Residents (2002).
The acute dietary intake risk quotient (RQa) was calculated as follows: where IESTI is the international estimated short-term intake, Ue is the unit weight in the edible portion, LP is the highest large portion provided, HR is the highest residue at the PHI (10 days) in the supervised field trials and v is a variability factor (v = 3). ARfD (mg/kg bw) is the acute reference dose. The Ue, LP and bw data were compiled by the World Health Organization (WHO) (WHO 2020).

Method validation
Validation of the established method was carried out according to the SANTE 2019 guidelines, which included trueness, precision, sensitivity, linearity, reproducibility and ME (SANTE 2019). The recoveries were shown in Fig. 2. The intra-day recoveries of pyraclostrobin, BF-500-3 and fluopimomide were 79-94%, 76-87% and 84-91%, respectively. The inter-day recoveries of pyraclostrobin, BF-500-3 and fluopimomide were 81-91%, 77-87% and 84-90%, respectively. The results indicated an acceptable trueness. The intra-day RSDs and inter-day RSDs ranged from 1.0 to 14.5% and 1.3 to 9.6%, respectively, which proved the good precision and reproducibility of the established method. The LOQs, LODs, calibration curves and MEs were shown in Table 1. The LOQs of the analytical method were 0.002 mg/kg (the lowest spiked level). The LODs ranged from 1.90 × 10 −5 ng to 5.42 × 10 −5 ng. The linearity of the method for all target compounds was satisfactory, with r ≥ 0.9929. The current results were consistent with the acceptable range established in the SANTE 2019 guidelines. The MEs of the three compounds in garlic chive, garlic scape and garlic ranged from − 32.82 to 24.88%. The results showed that the MEs of the three compounds had different degrees of signal enhancement or suppression in different matrices. Therefore, to ensure the trueness of the analytical method, the matrix calibration curve was used for quantification in this study (Man et al. 2019).

Residue levels of fluopimomide, pyraclostrobin and its metabolite in garlic ecosystems
Terminal residues The terminal residue trial results for 30% SC applied to garlic in six regions of China according to the GAP (135 g a.i./ha, three applications at intervals of 7 days, PHI of 10 days) were shown in Table 2. At the recommended PHI (10 days), the terminal residues of pyraclostrobin, BF-500-3 and fluopimomide were below 0.77, 0.12 and 0.16 mg/kg in garlic chive; below 0.22, 0.002 and 0.027 mg/ kg in garlic scape; and below 0.002, 0.002 and 0.002 mg/kg in garlic, respectively. At sampling day 14, the terminal residues of pyraclostrobin, BF-500-3 and fluopimomide were below 0.35, 0.061 and 0.095 mg/kg in garlic chive; below 0.22, 0.0070 and 0.037 mg/kg in garlic scape; and below 0.002, 0.002 and 0.002 mg/kg in garlic, respectively. According to GB2763-2021 (National Food Safety Standard-Maximum Residue Limits for Pesticides in Food, issued by the Ministry of Agriculture of China), the definition of the residue for compliance with the maximum residue limit (MRL) for plant commodities are pyraclostrobin and fluopimomide, respectively (ICAMA 2021). At present, MRLs for pyraclostrobin and fluopimomide in garlic chive, garlic scape and garlic have not been set in China, but pyraclostrobin residues in garlic chive were lower than the MRL of 1 mg/kg set by Korea, and pyraclostrobin residues in garlic were below the Codex Alimentarius Commission (CAC) MRL of 0.15 mg/kg. The present results showed that the recommended use conditions (135 g a.i./ha, three applications at intervals of 7 days, PHI of 10 days) were safe and reasonable.
The residue amounts of the three compounds on the three different edible parts of garlic plant were ranked garlic chive > garlic scape > garlic. These results were closely related to the morphological characteristics of garlic chive and garlic scape. The whole leaf of garlic chive has a flat structure and fluffy surface, and pesticides adhere better to this surface than the smooth garlic scape surface (Bian et al. 2020). During pesticide application, garlic grew in the soil, and the pesticide was applied directly to the garlic plant rather than to the garlic roots and soil. In addition, the skin of garlic was removed during sample analysis, which caused the residues in garlic at all intervals to harvest to be lower than the LOQ. Table 2 showed the residual data for the PHI (10 days) and its nearby intervals to harvest (0, 5, 7, 10, 14 and 21 days) in Shandong, Henan and Anhui. The average initial deposits (2 h after spraying) of pyraclostrobin, BF-500-3 and fluopimomide were 1.2-1.5, 0.032-0.12 and 0.24-0.28 mg/kg in garlic chive, and 0.40-0.83, 0.002-0.01 and 0.066-0.14 mg/ kg in garlic scape, respectively. The residue distribution in garlic plants followed a trend: smaller intervals to harvest led to higher residues of pyraclostrobin and fluopimomide. Concentrations of both pyraclostrobin and fluopimomide were reduced by more than 53% relative to the initial concentrations in garlic chive and garlic scape on day 14. The concentration of these two pesticides in garlic chive dissipated by more than 83% at the three sites 21 days after application. Fourteen days after application in Shandong and Henan, fluopimomide residues on garlic scape were reduced by more than 72%, and that in Anhui they decreased to less than the LOQ at 5 days. The concentrations of pyraclostrobin decreased by more than 52% on day 21 in Shandong and Henan, and in Anhui, the concentrations in garlic scape rapidly decreased to undetectable levels.

Residue levels at different intervals to harvest
The above results indicated fast dissipation of the two pesticides. Previous studies have also supported this conclusion. For example, fluopimomide residues decreased by more than 68% after 14 days, and the half-lives were 2.8-4.2 days in cucumber . At 14 days after application, the residues of fluopimomide in taro were below the LOQ (< 0.01 mg/kg) (Tripathi et al. 2015). Han et al. reported that the half-lives of pyraclostrobin in cowpea were 1.5-2.3 days and that the pesticide dissipated by approximately 90% within 7 days (Han et al.). Malhat et al. reported that the half-life of pyraclostrobin in strawberry was 5 days and that the concentrations of pyraclostrobin were reduced by more than 82% on day 14 after treatment (Malhat et al. 2019). The rapid dissipation of these two pesticides may be caused by the physical and chemical properties of fungicides and environmental conditions such as light, temperature and humidity (Gao et al. 2019;Heimbach et al. 2016;Lei et al. 2015;Sun et al. 2016). Dissipation behavior may also be related to crop varieties (Tripathi et al. 2015).
Previous studies have shown that BF-500-3 concentration showed trends of increasing first and then decreasing in corn stalk (You et al. 2012), pepper (Gao et al. 2019) and cucumber . In this study, the dissipation of BF-500-3 in garlic scape was consistent with the results of previous studies. The maximum concentrations of BF-500-3 were observed at 5 days (Shandong), 10 days (Henan) and 5 days (Anhui). As the metabolite BF-500-3 occurred in much smaller amounts than the parent pyraclostrobin, dissipation of pyraclostrobin and total pyraclostrobin showed similar decreasing tendencies. The level of BF-500-3 in garlic scape was low, with concentrations of 0.002-0.019 mg/ kg. The concentrations of the three compounds were all below the LOQs in all garlic samples.
The above results showed that, after the application of 30% SC, residues had not accumulated excessively in the crops at the PHI (10 days). The recommended use conditions (135 g a.i./ha, three applications at intervals of 7 days, PHI Table 2 Residue levels of fluopimomide, pyraclostrobin, BF-500-3 and total pyraclostrobin (sum of pyraclostrobin and BF-500-3, expressed as pyraclostrobin)  of 10 days) were shown to be safe and reliable. Moreover, this study compiled data on the behavior of fluopimomide, pyraclostrobin and its metabolite BF-500-3, providing effective data and scientific guidance for field applications of pyraclostrobin and fluopimomide.

Dietary intake risk assessment
Since the human body is often the final accumulator of chemical pollutants via food consumption, which can lead to health problems, dietary risk assessments of pesticide residues are critical (Lehmann et al. 2017). The potential risk to humans of pesticides in garlic ecosystems is assessed by estimating RQ (Eqs. (3)- (6)). According to the JMPR 2003 report, the ADI and ARfD of pyraclostrobin are 0.03 and 0.05 mg/kg bw, respectively (FAO 2003). According to GB2763-2021, the ADI of fluopimomide is 0.18 mg/kg bw (ICAMA 2021).

Chronic dietary intake risk
In order to take into account the total risk of pesticide residues on all possible crops, an assessment of the chronic dietary intake risk was carried out involving crops for which pesticides were being registered and had been registered. The STMR values of garlic chive (dark vegetable), garlic scape (light vegetable) and garlic (soy sauce) obtained from the supervised field trials were used to calculate NEDI. If STMRi was not available for a particular crop, the corresponding MRL value was applied instead to calculate NEDI. The reference MRLs were selected according to the following chain: China > CAC > USA > European Union > Australia > Korea > Japan. In addition, for the same kind of crops, the highest MRL was selected when calculating the corresponding NEDI. The residual data obtained by this method represent a reasonable worst-case estimate of risk assessment. Registered crops and MRL selections were shown in Tables S5 and S6, and the results of chronic dietary risk assessment were shown in Table 3. The NEDIs of pyraclostrobin and fluopimomide were calculated as 0.92 mg and 0.041 mg, with RQs of 48.42% and 0.36%, respectively. RQc did not exceed 100%, which indicated that long-term consumption of garlic and its products containing pyraclostrobin and fluopimomide would not pose dietary intake risks.
Acute dietary intake risk At present, only acute dietary data for pyraclostrobin on garlic were available, so the acute dietary risk of pyraclostrobin on garlic was evaluated in this paper. According to the WHO, garlic consumers can be divided into two groups by age. The dietary intake risks of different groups can be calculated based on their body weight and diet. The RQc values for different groups (children (1-6 years) and the general population (> 1 year)) were shown in Table 4. The results showed that the IESTIs for garlic were 3.10 × 10 −5 and 7.47 × 10 −5 mg/kg bw for children and the general population, respectively, and the RQa values were 0.15% and 0.06%. The risk of exposure to pyraclostrobin on garlic in children was higher than that in the general population, but the risk value was very low, and the acute dietary risk was negligible. Therefore, these results suggested that the potential chronic dietary intake risk induced by pyraclostrobin and fluopimomide in garlic and its products was not significant for people, and the acute dietary intake risk of pyraclostrobin in garlic is negligible for consumers.

Conclusion
In this study, a QuEChERS method combined with HPLC-MS/MS was developed and validated for determining fluopimomide, pyraclostrobin and its metabolite BF-500-3 in garlic chive, garlic scape and garlic samples. The method exhibited satisfactory specificity, linearity, trueness, sensitivity, precision and reproducibility. Garlic chive, garlic scape and garlic samples sprayed with 30% SC from six representative regions of China were collected and determined using the developed method. At intervals to harvest of 10 days (PHI) and 14 days, the terminal residues of pyraclostrobin, BF-500-3, total pyraclostrobin (sum of pyraclostrobin and BF-500-3) and fluopimomide were below 0.77, 0.12, 0.89 and 0.16 mg/kg in garlic ecosystems. The risk quotients (RQc and RQa) were both lower than 100% for all consumers. These results show that the recommended use conditions (135 g a.i./ha, three applications at intervals of 7 days, PHI of 10 days) were reasonable and safe for the field application of 30% SC to garlic. The findings of this study provide valuable information on the use of pyraclostrobin and fluopimomide in the field, and a scientific reference with which the Chinese government can establish MRL data.