Dissipation kinetics, food safety evaluation and decontamination of chlorantraniliprole in cowpea.

Cowpea is known for its high protein content (18-25%) and also chiefly raised for green fodder. The infesting pests, pod borer and aphids are the most destructive ones. To control these pests, chlorantraniliprole emerges as a promising molecule. Thus, its needs to assess the dissipation nature of the chlorantraniliprole. Hence, a trial was conducted at IIVR, Varanasi, India. The residue analysis was done through solid phase extraction method followed by gas chromatoghraphy analysis. The analytical method was standardized and validated according to international standard. The half-life of chlorantraniliprole in cowpea pods was estimated in the range of 2.79- 2.33 days in the year-I and 2.51-2.32 days in the year-II for single dose (SD) and double dose (DD) respectively. Similarly, half-life of the chlorantraniliprole in leaves 2.43-2.27 days whereas, 1.94-1.70 days in case of soil. The exposure of the residues in pods were less than maximum permissible intake (MPI). The RQ values revealed that there could be negligible risk to earthworms and arthropods. Washing with boiling water was found the most effective decontamination treatment to remove residue from cowpea pods. Thus, it could be concluded that chlorantraniliprole does not pose any significant threat when uses in cowpea in a particular dose.

Simultaneous Monitoring and Decontamination of Pesticide Residues in Phytomedicine-Enriched Betel Leaf Utilizing QuEChERS-GC-MS/MS Technology to Safeguard Public Health.

BACKGROUND: The presence of undesirable substances, including pesticides (xenobiotics) in betel leaf (Piper betel), is a great concern for consumers because it is chewed and consumed directly. To protect the consumer's health, a modified QuEChERS method for monitoring purposes and subsequent decontamination process has been developed. OBJECTIVE: The goal of this work was to establish a multi-residue analytical method for monitoring nonpermitted organophosphorus pesticide residues in betel leaf, as well as cost-effective cleaning strategies. METHOD: The homogenized 15 g samples (20 betel leaf samples collected in West Bengal, India) were extracted with a modified QuEChERS method using acetonitrile, reconstituted to acetone, and finally analyzed by GC-MS/MS. Possible decontamination techniques (such as tap water washing, 2% saltwater washing, and lukewarm water washing) were evaluated. RESULTS: The limit of detection ranged from 0.003 to 0.005 mg/kg, and limit of quantification was 0.01 mg/kg. Recoveries ranged from 80 to 120% with RSDr 9%. One sample was found to contain three pesticides 4 to 7 times higher than MRLs. Suggested decontamination methods allowed reducing toxic traces below European limits. CONCLUSIONS: The suggested approach is useful for determining pesticide residues in betel leaves quickly. Traditional techniques of processing betel leaves may reduce pesticide residues below regulatory limits. HIGHLIGHTS: A multi-residue method and decontamination of pesticides in betel leaf using QuEChERS-GC-MS/MS technology with satisfactory method performance was achieved. Domestic decontamination techniques have a high efficacy in reducing pesticide residues from betel leaves, making them safe for human consumption.

Morphological characterization and distribution of antennal sensilla of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) using scanning electron microscopy.

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a serious polyphagous pest of various field and horticultural crops. A complete knowledge on the morphological features of antennal sensory structures is essential for efficient semiochemical-based control methods. The external structure and distribution of antennal sensilla in male and female adults of H. armigera were investigated using scanning electron microscopy. Eight distinct morphological types of sensilla were identified in both sexes: sensilla trichodea, sensilla basiconica, sensilla auricillica, sensilla coeloconica (multiporous), sensilla chaetica (uniporous), sensilla styloconica, sensilla squamiformia, and Böhm sensilla (aporous) in varying numbers and distribution along the length of the antennae. Of these sensilla, the most widespread are sensilla trichodea and sensilla basiconica on the antennae of both sexes. Female antennae have comparatively greater number of sensilla trichodea than male antennae. Among eight types of sensilla, sensilla basiconica, auricillica, styloconica type II, squamiformia, and Böhm sensilla were identified and reported for the first time in H. armigera. Sexual dimorphism in H. armigera was mainly detected as the variations in sensilla shape, numbers, and distribution of each type of sensilla. The sexual difference was observed in the numbers of sensilla coeloconica, chaetica, styloconica, and squamiformia per flagellomere. The possible functions of these sensilla were discussed in view of previously reported lepidopteran insects. The findings provide fundamental information on the morphology and distribution of antennal sensory structures in H. armigera. It would be useful for further detailed studies on physiological and behavioral function of each sensillum type and helpful for formulating related pest control methods.

A liquid chromatographic method for determination of acetamiprid and buprofezin residues and their dissipation kinetics in paddy matrices and soil.

The present study was conducted to investigate the residue status of two insecticides (acetamiprid and buprofezin) and their dissipation kinetics in three matrices viz. paddy grain, straw, and soil. The extraction procedure for residues of these two insecticides was executed using acetonitrile solvent. The analytical method was validated, which showed good linearity with the limit of quantification (LOQ) value of 0.01 and 0.02 mg kg-1 for acetamiprid and buprofezin, respectively. The recovery range was 79.67-98.33 % concerning all the matrices in both the insecticides. Acetamiprid (20% SP) and Buprofezin (25% SC) were applied separately in the paddy field in two doses: single dose (recommended dose) and double dose along with untreated control throughout the experiment. Residue analysis of these two insecticides in paddy (grain and straw) and soil was accomplished employing high-performance liquid chromatography (HPLC) with ultraviolet (UV) detector and confirmed by ultra-performance liquid chromatography (UPLC) coupled with mass spectrometry (UPLC-MS/MS). The dissipation data showed that acetamiprid exhibited higher dissipation in comparison with buprofezin. However, their persistence was found slightly higher in soil. The dissipation dynamics in the rice and soil were discussed with biological half-lives of both the insecticides. Consumer risk assessment study was also made considering its fate to the consumers.

Indigenous plant protection practices of Tripura, India.

BACKGROUND: Traditional plant protection strategies have an integral part of food production system in North Eastern state Tripura, India, which has bestowed with rich heritage and biodiversity. However, there is no comprehensive report on the indigenous plant protection practices (IPPPs) specific to insect and vertebrate pest management, being followed by the inhabitants of the region for centuries. The present study was conducted to investigate, collect, and document the vulnerable IPPP practices followed by the native people from far flung locations of the Tripura. METHODS: The study aimed to document the IPPP following semi-structured questionnaires, participatory interaction, and direct observations with a total of 200 informants. We have calculated the relative frequencies of citation (RFC) for IPPP and estimated principal component analysis to link the status of IPPP with socio-demographic factors of the informants. The relationship between the field of IPPP used and different covariates (age, education, occupation, gender, location, and house type) was assessed using the Kruskal-Wallis test and Chi-square test. The relationship between adoption level and the respondents' characteristics was analyzed using count regression analysis. RESULTS: The study found that the status of the IPPP has increased for mitigating pest issues. A total of 39 indigenous practices were recorded specifically to pest management from the ethnic people of Tripura, India. People acquired pretty knowledge about IPPP, and these were inherited from ancestors. The respondents in the study developed notable innovations for the management of many pest issues using locally available resources that warrant cost-effective and eco-friendly. Seed drying before storage to protect grain commodities was the most cited IPPP with a frequency of citation 0.675. In the field of IPPP used, the people primarily practiced agriculture + horticulture + storage category. An important implication from the study is the identification of two IPPP strategies in this region for the first time. Furthermore, the recorded IPPP used field was significantly associated with age, education, occupation, gender, locality, and house type. Likewise, the respondents' socio-demographic variables were coupled considerably with the adoption of specific IPPP. CONCLUSION: The reported IPPP for alleviating pest problems reflects the wisdom and generosity of the ethnic growers of Tripura, India. The study suggests the IPPP has strong potential in an integrated pest management approach passed down from generation to generation. The vulnerable practices largely remained unexplored due to inadequate scientific scrutiny and authenticity, yet in danger of being lost if not documented systematically. This study provides the first step toward accessing the valuable technology of untapped Tripura in IPPP and could be viable in paving action paradigm for their preservation, diffusion, and application with advanced pest management options.

Multiclass pesticide residue analysis in tobacco (Nicotiana tabacum) using high performance liquid chromatography-high resolution (Orbitrap) mass spectrometry: A simultaneous screening and quantitative method.

Public exposure to pesticides through tobacco has attracted serious attention. Here we report a simultaneous screening and quantitation method for the non-target multiresidue analysis of pesticides in different tobacco types. The method involved extraction of a homogenate (20 g, containing 2 g tobacco) in ethyl acetate (10 mL), cleanup of 2 mL extract by dispersive solid phase extraction with PSA (50 mg)+C18 (50 mg)+GCB (25 mg)+MgSO4 (100 mg), followed by reconstitution in 1 mL acetonitrile:water (3:7) and analysis using HPLC with Quadrupole-Orbitrap mass spectrometry. The high resolution accurate mass analysis was performed through sequential full-scan (resolution=35000) and variable data independent acquisition (resolution=17500) events. When the method was evaluated in a mixture of 181 pesticides, it effectively minimised matrix interferences and false negatives. The target compounds included 5 pairs of isomers and 27 pairs of isobars, which were distinguished based on chromatographic separation, mass resolving power and/or unique product ions. The screening detection limit (SDL) for 86.4% of the test pesticides was set at 5 ng/g, while the remainder had the SDLs at 10 ng/g (9.3%) and 40 ng/g (4.3%). Nearly, 75% of the compounds showed recoveries of 70-120% at 10 ng/g. The rest of the compounds showed satisfactory recoveries at 40 and 100 ng/g. In all cases, precision-RSDs were < 20%. The established method demonstrated a successful performance in four different types of tobacco matrices while aligning with the guidelines of SANTE and US-FDA. Owing to its efficiency, the method is recommended for screening and quantitation of multiclass pesticides in tobacco.

Amphiphilic polymer based nanoformulations of mancozeb for management of early blight in tomato.

Controlled release (CR) nanoformulations of Mancozeb (Manganese-zinc double salt of N, N-bisdithiocarbamic acid), a protective fungicide, have been developed using poly (ethylene glycols) (PEGs) based functionalized amphiphilic copolymers and evaluated for the management of early blight in tomato. During the field experiment, it was observed that number of infected leaflets/plants were less in developed formulation treated plants as compared to commercial products. Number of infected leaflets per plant was 2.40-4.60 and the number of fruits per plant were 6.40-9.00 at 50 mg L-1, whereas at 100 mg L-1, the corresponding numbers were 2.10-4.10 and 6.30-9.10 respectively. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, sufficient amount of active ingredient remains available for a reasonable period of time after application leading to reduced number of applications of pesticide.

Eco-friendly PEG-based controlled release nano-formulations of Mancozeb: Synthesis and bioefficacy evaluation against phytopathogenic fungi Alternaria solani and Sclerotium rolfsii.

Controlled release (CR) nano-formulations of Mancozeb (manganese-zinc double salt of N,N-bisdithiocarbamic acid), a protective fungicide, have been prepared using laboratory-synthesized poly(ethylene glycols) (PEGs)-based functionalized amphiphilic copolymers without using any surfactants or external additives. The release kinetics of the developed Mancozeb CR formulations were studied and compared with that of commercially available 42% suspension concentrate and 75% wettable powder. Maximum amount of Mancozeb was released on 42nd day for PEG-600 and octyl chain, PEG-1000 and octyl chain, and PEG-600 and hexadecyl chain, on 35th day for PEG-1000 and hexadecyl chain, on 28th day for PEG-1500 and octyl chain, PEG-2000 and octyl chain, PEG-1500 and hexadecyl chain, and PEG-2000 and hexadecyl chain in comparison to both commercial formulations (15th day). The diffusion exponent (n value) of Mancozeb in water ranged from 0.42 to 0.62 in tested formulations. The half-release (t1/2) values ranged from 17.35 to 35.14 days, and the period of optimum availability of Mancozeb ranged from 18.54 to 35.42 days. Further, the in vitro bioefficacy evaluation of developed formulations was done against plant pathogenic fungi Alternaria solani and Sclerotium rolfsii by poison food technique. Effective dose for 50% inhibition in mgL-1 (ED50) values of developed formulations varied from 1.31 to 2.79 mg L-1 for A. solani, and 1.60 to 3.14 mg L-1 for S. rolfsii. The present methodology is simple, economical, and eco-friendly for the development of environment-friendly CR formulations of Mancozeb. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, the maximum amount of active ingredient remains available for a reasonable period after application. In addition, the developed CR formulations were found to be suitable for fungicidal applications, allowing use of Mancozeb in lower doses.