Dissipation and residues determination of propamocarb in ginseng and soil by high-performance liquid chromatography coupled with tandem mass spectrometry

Two-year field trials were performed at two experimental sites to investigate dissipation and terminal residues of propamocarb in ginseng root, stem, leaf, and soil by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Mean recoveries ranged from 80.5 to 95.6 % with relative standard deviations (RSDs) of 5.5–9.1 % at fortified levels of 0.01, 0.02, 0.05 and 0.20 mg kg^?1. The half-lives of propamocarb were 5.00–11.36 days in root, 5.07–11.46 days in stem, 6.83–11.31 days in leaf and 6.44–8.43 days in soil. The terminal residues of propamocarb were below the maximum residue limits (MRLs) of EU (0.20 mg kg^?1) and South Korea (0.50 mg kg^?1 in fresh ginseng and 1.0 mg kg^?1 in dried ginseng) over 28 days after last spraying at recommended dosage. The results provide a quantitative basis for establishing the MRL and give a suggestion of safe and reasonable use of propamocarb in ginseng.     

Dissipation and residue behavior of mepiquat on wheat and potato field application

A modified LC-MS method for the analysis of mepiquat residue in wheat, potato, and soil was developed and validated. A hydrophilic interaction liquid chromatographic column has been successfully used to retain and separate the mepiquat. Mepiquat residue dynamics and final residues in supervised field trials at Good Agricultural Practice (GAP) conditions in wheat, potato, and soil were studied. The limits of quantification for mepiquat in all samples were all 0.007 mg kg^?1, which were lower than their maximum residue limits. At fortification levels of 0.04, 0.2, and 2 mg kg^?1 in all samples, recoveries ranged from 77.5 to 116.4 % with relative standard deviations of 0.4–7.9 % (n?=?5). The dissipation half-lives (T _1/2) of mepiquat in soil (wheat), wheat plants, soil (potato), and potato plants were 4.5–6.3, 3.0–5.6, 2.2–4.6, and 2.4–3.2 days, respectively. The final residues of mepiquat were below 0.153 mg kg^?1 in soil (wheat), 0.052–1.900 mg kg^?1 in wheat, below 0.072 mg kg^?1 in soil (potato), and below 1.173 mg kg^?1 in potato at harvest time. Moreover, pesticide risk assessment for all the detected residues was conducted. A maximum 0.0012 % of acceptable daily intake (150 mg kg^?1) for national estimated daily intake indicated low dietary risk of these products.     

Simultaneous determination of insecticide fipronil and its metabolites in maize and soil by gas chromatography with electron capture detection

An integrated method for the simultaneous determination of insecticide fipronil and its three metabolites, desulfinyl, sulfide, and sulfone, in maize grain, maize stem, and soil was developed. This three-step method uses liquid–solid extraction with ultrasound or mechanical grinding, followed by liquid–liquid partitioning and florisil solid-phase extraction (SPE) for cleanup. The quantification was conducted by gas chromatography–electron capture detection in triplicate for each sample. The method was validated with five replicates at three fortification concentrations, 0.002, 0.01, and 0.1 mg kg^?1, in each matrix and gave mean recoveries from 83 to 106 % with relative standard deviation ≤8.9 %. The limits of quantification (LOQ) were 0.002 mg kg^?1 for the compounds in all matrixes. In the field study in Beijing and Shandong 2012, fipronil-coated maize seeds were planted and the proposed method was applied for checking the possible existence of four compounds in maize and soil samples, but none of them contained residues higher than the LOQs in both application rates. Moreover, the dissipation of fipronil in soil fits first-order kinetics with half-lives 9.90 and 10.34 days in Beijing and Shandong, respectively. Combined with an adequate sample treatment, this technique offers good sensitivity and selectivity in the three complex matrixes. The results could provide guidance for the further research on pesticide distribution and safe use of fipronil as seed coat in cereals.     

Persistence and risk assessment of spiromesifen on tomato in India: a multilocational study

Supervised field trials were conducted at four different agro-climatic locations of India to evaluate the dissipation pattern and risk assessment of spiromesifen on tomato. Spiromesifen 240 SC was sprayed on tomato at 150 and 300 g a.i.?ha^?1. Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10 and 15 days after treatment and soil at 15 days after treatment. Quantification of residues was done on gas chromatograph–mass spectrophotometer in selective ion monitoring mode in the mass range of 271–274 (m/z). The limit of quantification of the method was found to be 0.05 mg kg^?1, while the limit of determination was 0.015 mg kg^?1. Residues were found below the LOQ of 0.05 mg kg^?1 in 10 days at both the doses of application at all the locations. Spiromesifen dissipated with a half-life of 0.93–1.38 days at the recommended rate of application and 1.04–1.34 days at the double the rate of application. Residues of spiromesifen in soil were detectable level (<0.05 mg kg^?1) after 15 days of treatment. A preharvest interval (PHI) of 1 day has been recommended on tomato on the basis of data generated under All India Network Project on Pesticide Residues. Spiromesifen 240 SC has been registered for its use on tomato by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of spiromesifen on tomato has been fixed by Food Safety Standard Authority of India, Ministry of Health and Family Welfare, Government of India as 0.3 μg/g after its risk assessment.     

Persistence and effect of processing on reduction of chlorantraniliprole residues on brinjal and okra fruits

Dissipation and decontamination of chlorantraniliprole (Coragen 18.5 SC) in brinjal and okra fruits were studied following field application at single and double doses of 30 and 60 g ai ha^?1, and the residues of the insecticide was estimated using LC-MS/MS. Initial residues of chlorantraniliprole at single and double doses on the fruits of brinjal were 0.72 and 1.48 mg kg^?1, while on okra fruits, the residues were 0.48 and 0.91 mg kg^?1, respectively. The residues reached below detectable level of 0.01 mg kg^?1 on the 10th day. Half-life of chlorantraniliprole at 30 and 60 g ai ha^?1 on brinjal was 1.58 and 1.80 days with the calculated waiting period of 0.69 and 2.38 days, whereas on okra, the values were 1.60 and 1.70 and 0 and 1.20 days, respectively. The extent of removal of chlorantraniliprole using simple decontaminating techniques at 2 h and 3 days after spraying was 40.99–91.37 % and 29.85–89.12 %, respectively, from brinjal fruits and 47.78–86.10 % and 41.77–86.48 %, respectively, from okra fruits.     

Persistence and dissipation of flubendiamide and its risk assessment on gherkin (Cucumis anguria L.)

A supervised open field trial was conducted to evaluate the dissipation pattern and risk assessment of flubendiamide in gherkin fruits following foliar application of Fame 480 SC at 60 and 120 g a.i.?ha^?1. Samples of gherkin fruits were drawn at different time intervals and quantified by HPLC-DAD. The maximum initial deposits of flubendiamide on gherkin were found to be 0.79 and 1.52 mg kg^?1, respectively, at recommended and double the recommended doses. The dissipation pattern of flubendiamide followed a first-order kinetics with half-lives of 1.87 to 2.16 days at 60 and 120 g a.i.?ha^?1, respectively. The limit of quantification of flubendiamide and desiodo flubendiamide was observed to be 0.01 mg kg^?1 for gherkin fruit and soil substrates. Theoretical maximum residue contribution (TMRC) for flubendiamide was calculated and found to be well below the maximum permissible intake (MPI) on gherkin fruits. Thus, the application of flubendiamide at the recommended dose on gherkin fruits presents no human health risks and safe to consumers.     

Cadmium background concentrations to establish reference quality values for soils of São Paulo State,Brazil

Proper assessment of soil cadmium (Cd) concentrations is essential to establish legislative limits. The present study aimed to assess background Cd concentrations in soils from the state of São Paulo, Brazil, and to correlate such concentrations with several soil attributes. The topsoil samples (n?=?191) were assessed for total Cd contents and for other metals using the USEPA 3051A method. The background concentration was determined according to the third quartile (75th). Principal component analysis, Spearman correlation, and multiple regressions between Cd contents and other soil attributes (pH, cation exchange capacity (CEC), clay content, sum of bases, organic matter, and total Fe, Al, Zn, and Pb levels) were performed. The mean Cd concentration of all 191 samples was 0.4 mg kg^?1, and the background concentration was 0.5 mg kg^?1. After the samples were grouped by parent material (rock origin) and soil type, the background Cd content varied, i.e., soils from igneous, metamorphic, and sedimentary rocks harbored 1.5, 0.4, and 0.2 mg kg^?1 of Cd, respectively. The background Cd content in Oxisols (0.8 mg kg^?1) was higher than in Ultisols (0.3 mg kg^?1). Multiple regression demonstrated that Fe was primarily attributed to the natural Cd contents in the soils (R ²?=?0.79). Instead of a single Cd background concentration value representing all São Paulo soils, we propose that the concentrations should be specific for at least Oxisols and Ultisols, which are the primary soil types.     

Dissipation kinetics and effect of different decontamination techniques on the residues of emamectin benzoate and spinosad in cowpea pods

Dissipation and decontamination of the semisynthetic macrolide emamectin benzoate and the natural insecticide spinosad on cowpea pods were studied following field application at single and double doses of 11.0 and 22 and 73 and 146 g ai ha^?1, respectively. Residues of these naturalytes were estimated using LC-MS/MS. The initial deposit of 0.073 and 0.153 mg kg^?1 of emamectin benzoate dissipated below quantitation level on the fifth and seventh day at single and double dosage, respectively. For spinosad, the initial deposits of 0.94 and 1.90 mg kg^?1 reached below quantitation level on the 7th day and 15th day at single and double dosage, respectively. The half-life of emamectin benzoate and spinosad was 1.13–1.49 and 1.05–1.39 days with the calculated safe waiting period of 2.99–6.12 and 1.09–3.25 days, respectively, for single and double dosage. Processing of the harvestable pods with different decontamination techniques resulted in 33.82 to 100 % removal 2 h after the application of emamectin benzoate and 100 % removal 3 days after spraying, while the removal was 42.05 to 87.46 % 2 h after the application of spinosad and 38.05 to 68.08 % 3 days after application.     

Environmental fate of chlorantraniliprole residues on cauliflower using QuEChERS technique

Chlorantraniliprole, an anthranilic diamide insecticide with novel mode of action is found effective against several lepidopteran as well as coleopteran, dipteran, and hemipteran pests. The present studies were carried out to study the dissipation pattern of chlorantraniliprole on cauliflower and to suggest suitable waiting period for the safety of consumers. Quick, easy, cheap, effective, rugged, and safe method was used for the extraction and cleanup of samples and the residues of chlorantraniliprole were estimated using high-performance liquid chromatograph (HPLC) and confirmed by liquid chromatograph–mass spectrometer and high-performance thin layer chromatograph. Following three applications of chlorantraniliprole (Coragen 18.5 SC) at recommended dose (9.25 g a.i.?ha^?1) and double the recommended dose (18.50 g a.i.?ha^?1), the average initial deposits of chlorantraniliprole were observed to be 0.18 and 0.29 mg kg^?1, respectively. These deposits were found to be less than the maximum residue limit of 2.0 mg kg^?1 prescribed by the Codex Alimentarius Commission. These residues dissipated below the limit of quantification of 0.10 mg kg^?1 after 3 and 5 days at recommended and double the recommended dosages, respectively. The half-life value (T _1/2) of chlorantraniliprole was worked out to be 1.36 days following its application at recommended dosages. Hence, the use of this pesticide at recommended dosages does not seem to pose any risk, and a waiting period of 1 day is suggested for safe consumption of cauliflower curds.     

Heavy metals in the habitat and throughout the food chain of the Neotropical otter, Lontra longicaudis, in protected Mexican wetlands

Top predators like the Neotropical otter, Lontra longicaudis annectens, are usually considered good bioindicators of habitat quality. In this study, we evaluated heavy metal contamination (Hg_tot, Pb, Cd) in the riverine habitat, prey (crustaceans and fish), and otter feces in two Ramsar wetlands with contrasting upstream contamination discharges: Río Blanco and Río Caño Grande in Veracruz, Mexico, during the dry, the wet, and the nortes seasons. Most comparisons revealed no differences between sites while seasonal differences were repeatedly detected for all of the compartments. Higher concentrations of Pb during the dry season and of Cd during the wet season in otter feces mirrored differences detected in the most seasonally consumed prey. Compared with fecal methylmercury values reported for the European otter (0.25–0.75 mg kg^?1) in unprotected areas, the Hg_tot levels that we measured were lower (0.02–0.17 mg kg^?1). However, Pb (117.87 mg kg^?1) and Cd (9.14 mg kg^?1) concentrations were higher (Pb, 38.15 mg kg^?1 and Cd, 4.72 mg kg^?1) in the two Ramsar wetlands. Protected areas may shelter species, but those with water-linked diets may suffer the effect of chemicals used upstream.     

Modeling of Cr contamination in the agricultural lands of three villages near the leather industry in Kasur,Pakistan, using statistical and GIS techniques

Kasur is one of the hubs of leather industry in the Punjab, Pakistan, where chrome tanning method of leather processing is extensively being used. Chromium (Cr) accumulation levels in the irrigation water, soil, and seasonal vegetables were studied in three villages located in the vicinity of wastewater treatment plant and solid waste dumping site operated by the Kasur Tanneries Waste Management Agency (KTWMA). The data was interpreted using analysis of variance (ANOVA), clustering analysis (CA), and principal component analysis (PCA). Interpolated surface maps for Cr were generated using the actual data obtained for the 30 sampling sites in each of the three villages for irrigation water, soil, and seasonal vegetables. The level of contamination in the three villages was directly proportional to their distance from KTWMA wastewater treatment plant and the direction of water runoff. The highest level of Cr contamination in soil (mg kg^?1) was observed at Faqeeria Wala (37.67), intermediate at Dollay Wala (30.33), and the least in Maan (25.16). A gradational variation in Cr accumulation was observed in the three villages from contaminated wastewater having the least contamination level (2.02–4.40 mg L^?1), to soil (25.16–37.67 mg kg^?1), and ultimately in the seasonal vegetable crops (156.67–248.33 mg kg^?1) cultivated in the region, having the highest level of Cr contamination above the permissible limit. The model used not only predicted the current situation of Cr contamination in the three villages but also indicated the trend of magnification of Cr contamination from irrigation water to soil and to the base of the food chain. Among the multiple causes of Cr contamination of vegetables, soil irrigation with contaminated groundwater was observed to be the dominant one.     

Metabolic degradation of imidacloprid in paddy field soil

The metabolic degradation and persistence of imidacloprid in paddy field soil were investigated following two applications of imidacloprid at 20 and 80 g a.i. ha^?1 at an interval of 10 days. The soil samples were collected at various time intervals. The limit of quantification for the analysis of imidacloprid and its metabolites was obtained at the concentration of 0.01 mg kg^?1. The initial deposits of total imidacloprid were found to be 0.44 and 1.61 mg kg^?1 following second applications. These residues could not be detected after 60 and 90 days following second applications of imidacloprid at lower and higher dosages, respectively. In soil, urea metabolite was found to be the maximum, followed by olefine, nitrosimine, 6-chloronicotinic acid, 5-hydroxy and nitroguanidine. The half-life values (t _1/2) of imidacloprid were worked out to be 12.04 and 11.14 days, respectively, when applied at lower and higher doses, respectively.     

Residual behavior of quizalofop ethyl on onion (Allium cepa L.)

Quizalofop ethyl, a phenoxy propionate herbicide, is used for postemergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the dissipation kinetics of quizalofop ethyl on onion for two seasons. A simple, rapid, and sensitive method for estimation of quizalofop ethyl residues in onion and soil was developed and validated. The recoveries of quizalofop ethyl residues from onion and soil at different spiking level range from 84.81 to 92.68 %. The limit of quantification of this method was found to be 0.01 μg g^?1. The risk assessment through consumption of the onion in comparison to its acceptable daily intake which is an important parameter for the safety of the consumer was also evaluated. Standardized methodology supported by recovery studies was adopted to estimate residues of quizalofop ethyl on onion and soil. The average initial deposits of quizalofop ethyl on onion were observed to be 0.25 and 0.33 mg kg^?1, following single application of the herbicide at 50 g active ingredient (a.i.) ha^?1 during 2009 and 2010, respectively. The half-life values (T _1/2) of quizalofop ethyl on onion crop were worked out to be 0.85 and 0.79 days, respectively, during 2009 and 2010. At harvest time, the residues of quizalofop ethyl on onion and soil were found to be below the determination limit of 0.01 mg kg^?1 following single application of the herbicide at 50 and 100 g a.i. ha^?1 for both the periods.     

Residues and dissipation of trifloxystrobin and its metabolite in tomatoes and soil

A simple residue analytical method using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure for the determination of trifloxystrobin and its metabolite trifloxystrobin acid (CGA321113) in tomato and soil was developed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The limits of detection were 0.0005 mg/kg for trifloxystrobin and 0.001 mg/kg for trifloxystrobin acid, respectively. The average recoveries in tomato and soil ranged from 73–99 % for trifloxystrobin and 75–109 % for trifloxystrobin acid, with relative standard deviations below 15 %. The method was then used to study the dissipation and residues in tomato and soil. The dissipation half-lives of trifloxystrobin in tomato were 2.9 days (Beijing) and 5.4 days (Shandong), while in soil were 1.9 days (Beijing) and 3.0 days (Shandong), respectively. The final results showed that the major residue compound was trifloxystrobin in tomato whereas it was its metabolite, trifloxystrobin acid, in soil. The final residues of total trifloxystrobin (including trifloxystrobin acid) were below the EU maximum residue limit of 0.5 mg kg^?1 in tomato 3 days after the treatment.     

Soil respiration,labile carbon pools,and enzyme activities as affected by tillage practices in a tropical rice–maize–cowpea cropping system

In order to identify the viable option of tillage practices in rice–maize–cowpea cropping system that could cut down soil carbon dioxide (CO₂) emission, sustain grain yield, and maintain better soil quality in tropical low land rice ecology soil respiration in terms of CO₂ emission, labile carbon (C) pools, water-stable aggregate C fractions, and enzymatic activities were investigated in a sandy clay loam soil. Soil respiration is the major pathway of gaseous C efflux from terrestrial systems and acts as an important index of ecosystem functioning. The CO₂–C emissions were quantified in between plants and rows throughout the year in rice–maize–cowpea cropping sequence both under conventional tillage (CT) and minimum tillage (MT) practices along with soil moisture and temperature. The CO₂–C emissions, as a whole, were 24 % higher in between plants than in rows, and were in the range of 23.4–78.1, 37.1–128.1, and 28.6–101.2 mg m^?2 h^?1 under CT and 10.7–60.3, 17.3–99.1, and 17.2–79.1 mg m^?2 h^?1 under MT in rice, maize, and cowpea, respectively. The CO₂–C emission was found highest under maize (44 %) followed by rice (33 %) and cowpea (23 %) irrespective of CT and MT practices. In CT system, the CO₂–C emission increased significantly by 37.1 % with respect to MT on cumulative annual basis including fallow. The CO₂–C emission per unit yield was at par in rice and cowpea signifying the beneficial effect of MT in maintaining soil quality and reduction of CO₂ emission. The microbial biomass C (MBC), readily mineralizable C (RMC), water-soluble C (WSC), and permanganate-oxidizable C (PMOC) were 19.4, 20.4, 39.5, and 15.1 % higher under MT than CT. The C contents in soil aggregate fraction were significantly higher in MT than CT. Soil enzymatic activities like, dehydrogenase, fluorescein diacetate, and β-glucosidase were significantly higher by 13.8, 15.4, and 27.4 % under MT compared to CT. The soil labile C pools, enzymatic activities, and heterotrophic microbial populations were in the order of maize?>?cowpea?>?rice, irrespective of the tillage treatments. Environmental sustainability point of view, minimum tillage practices in rice–maize–cowpea cropping system in tropical low land soil could be adopted to minimize CO₂–C emission, sustain yield, and maintain soil health.     

Residual behavior and risk assessment of flubendiamide on tomato at different agro-climatic conditions in India

Supervised field trials were conducted at four different agro-climatic zones in India to evaluate the dissipation pattern and risk assessment of flubendiamide on tomato. Flubendiamide 480 SC was sprayed on tomato at 48 and 96 g active ingredient (a.i.) ha^?1. Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10, 15, and 20 days after treatment. Quantification of residues was done on a high-performance liquid chromatography (HPLC) device with a photo diode array detector. The limit of quantification (LOQ) of this method was found to be 0.01 mg kg^?1 while limit of detection (LOD) being 0.003 mg kg^?1. Residues of flubendiamide were found below the determination limit of 0.01 mg kg^?1 in 20 days at both the dosages in all the locations. The half-life of flubendiamide at an application rate of 48 g a.i.?ha^?1 varied from 0.33 to 3.28 days and at 48-g a.i. ranged from 1.21 to 3.00 days. On the basis of data generated under the All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 1 day has been recommended, and the flubendiamide 480 SC has been registered for its use on tomato by the Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on tomato has been fixed by the Ministry of Health and Family Welfare, Government of India under Food Safety Standard Authority of India, as 0.07 μg g^?1 after its risk assessment.     

An assessment of contamination of the Fusaro Lagoon (Campania Province,southern Italy) by trace metals

The Fusaro Lagoon is a shallow lagoon, located in SW Italy, largely influenced in the last decades by several anthropic impacts. The study examined the pollution status of the lagoon, during year 2011–2012 at nine sampling stations with the aim to find out proper measurements of water lagoon restoration. Concentrations of heavy metals (HMs) (aluminium [Al], barium [Ba], cadmium [Cd], copper [Cu], iron [Fe], manganese [Mn], vanadium [V] and zinc [Zn]) were examined in water, sediments and specimens of the ascidian Ciona intestinalis sp. A. Low levels of dissolved oxygen concentration were detected at many stations, with mean values of 5.2–6.4 mg L^?1. The redox potential of surface waters was also low, ?2.7 to 50.7 mV. Sediments possessed high organic matter content, 17.7–29.4 %. In sediments, the mean Zn level, 251.4 mg kg^?1, was about sixfold higher than that recorded in year 2000 (38.5 mg kg^?1) and considerably higher than that recorded in 2007 (191 mg kg^?1). The mean levels of Cd were outstandingly high, with a mean value of 70.5 mg kg^?1, about 30- and 50-fold higher than those determined in 2000 and 2007, respectively. Cadmium (Cd), Cu and nickel (Ni) appeared in excess with respect to most current guidelines, reaching significant pollution levels. C. intestinalis sp. A was detected only at few stations, with metals accumulated preferentially in the body in respect to the tunic, from 1.2 times for Zn (178 mg kg^?1) to 4.0 times for V (304 mg kg^?1). Data suggests the necessity of an immediate action of eco-compatible interventions for environmental restoration.     

Persistence of chlorantraniliprole granule formulation in sugarcane field soil

Chlorantraniliprole, an anthranilic diamide insecticide with novel mode of action, is found effective against several lepidopteran as well as coleopteran, dipteran, and hemipteran pests. The present studies were carried out to study the persistence pattern of chlorantraniliprole on sugarcane field soil following application of granule formulation. The residues of chlorantraniliprole were estimated using high performance liquid chromatograph (HPLC) and confirmed by liquid chromatograph-mass spectrometry (LC-MS/MS). Following application of chlorantraniliprole (Ferterra 0.4G) at 100 and 200 g a.i. ha^?1, the average initial deposits of chlorantraniliprole were observed to be 0.88 and 1.59 mg kg^?1, respectively. These residues dissipated below the limit of quantification (LOQ) of 0.01 mg kg^?1 after 56 days of the application of insecticides at both the dosages. The half-life values (t _1/2) of chlorantraniliprole were worked out to be 8.36 and 8.25 days, at recommended and double the recommended dosages, respectively.     

Cadmium accumulation characteristics of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don

In a preliminary study, we found that the cadmium (Cd) concentrations in shoots of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don exceeded the critical value of a Cd-hyperaccumulator (100 mg kg^?1), indicating that these two farmland weeds might be Cd-hyperaccumulators. In this study, we grew these species in soil containing various concentrations of Cd to further evaluate their Cd accumulation characteristics. The biomasses of C. hirsuta and G. affine decreased with increasing Cd concentrations in the soil, while the root/shoot ratio and the Cd concentrations in shoot tissues increased. The Cd concentrations in shoots of C. hirsuta and G. affine reached 121.96 and 143.91 mg kg^?1, respectively, at the soil Cd concentration of 50 mg kg^?1. Both of these concentrations exceeded the critical value of a Cd-hyperaccumulator (100 mg kg^?1). The shoot bioconcentration factors of C. hirsuta and G. affine were greater than 1. The translocation factor of C. hirsuta was less than 1 and that of G. affine was greater than 1. These findings indicated that C. hirsuta is a Cd-accumulator and G. affine is Cd-hyperaccumulator. Both plants are distributed widely in the field, and they could be used to remediate Cd-contaminated farmland soil in winter.     

Safety evaluation of flubendiamide and its metabolites on cabbage and persistence in soil in different agroclimatic zones of India

Supervised field trials following good agricultural practices were conducted at the research farms of four agricultural universities located at four different agroclimatic zones of India to evaluate the persistence and dissipation of flubendiamide and its metabolite, des-iodo flubendiamide, on cabbage. Two spray applications of flubendiamide 480 SC of standard and double dose at the rate of 24 and 48 g a.i. ha^?1 were given to the crop at a 15-day interval, and the residues of flubendiamide 2 h after spray were found in the range of 0.107–0.33 and 0.20–0.49 mg kg^?1 at respective doses. Residue of des-iodo flubendiamide was not detected in any cabbage sample during study period. No residues were found in the soil samples collected from all treated fields after 15 days of application. On the basis of data generated under All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 10 days has been recommended, and the flubendiamide 480 SC has been registered for its use on cabbage by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on cabbage has been fixed by the Ministry of Health and Family Welfare, Government of India, under Food Safety Standard Authority of India as 0.05 μg/g after its risk assessment.