Dissipation kinetics and the evaluation of dietary risks associated with deltamethrin, ethion, fenazaquin, and fenpropathrin on bell pepper (Solanum annuum L.).

Bell peppers, a globally significant crop, face infestations from various pests. In a study, bell peppers were treated with deltamethrin, ethion, fenazaquin, and fenpropathrin at recommended and double the doses, repeated twice with a 10-day interval. The QuEChERS method underwent validation for linearity, matrix match, accuracy, and precision in bell pepper matrices for residue analysis. The limit of detection for the tested pesticides on bell peppers was 0.01 mg/L, with a quantification limit of 0.05 mg/L. Recovery studies showed a range of 94.80% to 102.80%. Initial deposits of deltamethrin, ethion, fenazaquin, and fenpropathrin on bell peppers at recommended doses were 0.371, 1.237, 0.617, and 0.640 mg/L, respectively, and at double doses were 0.712, 1.945, 1.221, and 1.189 mg/L, respectively. Safe waiting periods of 10, 11, 10, and 8 days were suggested for deltamethrin, ethion, fenazaquin, and fenpropathrin, respectively. The corresponding half-lives for the pesticides were 1.96, 1.79, 2.06, and 1.69 days, all following first-order dissipation kinetics. Dietary risk assessment indicated Hazard Quotients (HQ) below 1 and Theoretical Maximum Daily Intake (TMDI) below Acceptable Daily Intake (ADI) and Maximum Permissible Intake (MPI) levels. Therefore, at their recommended doses, the pesticides were deemed safe for bell pepper cultivation.

Residue estimation and dietary risk assessment of fenvalerate, novaluron, and profenofos in bell pepper grown under protected and open field conditions.

Residue studies were conducted in bell pepper crops (green and yellow bell pepper) to ensure the safe use of fenvalerate, profenofos, and novaluron (under open field and protected conditions) in randomized block design (RBD) following three applications at a 10-day interval over two consecutive years, 2021 and 2022. A robust analytical method was developed using quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) for the determination of pesticide residues in bell pepper samples. The half-lives for fenvalerate were 2.47-2.87 and 2.50-3.03 days on bell pepper under open field conditions, whereas the corresponding values for bell pepper under protected conditions were 3.84-4.58 and 4.17-4.71 days, during 2021 and 2022, respectively. Profenofos displayed half-lives of 2.03-2.65 and 2.15-2.77 days in open field conditions and 3.05-3.89 and 3.16-3.78 days in protected conditions during 2021 and 2022, respectively. Similarly, novaluron had half-lives of 2.87-3.49 and 3.24-3.75 days under protected conditions in 2021 and 2022, respectively. The maximum residue limits (MRLs) were calculated to be 0.6 mg/kg for fenvalerate, while for profenofos it was 0.7 mg/kg on bell pepper under open field conditions at double doses, at the proposed pre-harvest interval (PHI) of 3 days. Likewise, for bell peppers grown under protected conditions, MRLs at the PHI of 3 days were determined to be 0.8 mg/kg for fenvalerate, 0.3 mg/kg for novaluron, and 1.5 mg/kg for profenofos. A dietary risk assessment study indicated that the percentage of acute hazard index (% aHI) was significantly lower than 100, and hazard quotient (HQ) values were below 1, signifying no acute or chronic risk to consumers. These findings underscore the safety of consuming bell peppers treated with fenvalerate, profenofos, and novaluron under the protected and open field conditions.

Residue behaviour and health risk assessment of chlorpyrifos and mancozeb in apple fruits and soil.

Mancozeb residue estimation was done using second derivative ultraviolet spectroscopy by Shimadzu ultraviolet-visible spectrophotometer, and chlorpyrifos was estimated by QuEChERS technique using GC-FPD. The persistence for chlorpyrifos was carried out at two locations, and for mancozeb, persistence studies were carried out at four locations. Initial deposits of mancozeb on apple fruits ranged from 1.33 to 1.63 mg/kg at the recommended dose and from 2.55 to 3.26 mg/kg at double the recommended dose at all four locations. Chlorpyrifos residues in apple fruits had an initial deposit of 0.94-0.99 mg/kg at recommended dose and 1.75-1.92 mg/kg at double the recommended dose. Mancozeb residues in apple fruit were below the detection limit (BDL) after 20 days at recommended dose and after 25 days at double the recommended dose at two locations, while mancozeb residue at the other two locations and the residues of chlorpyrifos at all locations reached BDL after 15 and 20 days at recommended and double the recommended doses, respectively. Half-life of mancozeb varied from 3.07 to 4.02 days at recommended dose and from 3.30 to 4.32 days at double the recommended dose, whereas chlorpyrifos residues dissipated to half their initial concentration on 2.33-2.35 days at recommended dose and 2.89-2.90 days at double the recommended dose. The soil samples showed no presence of residues of chlorpyrifos and mancozeb at harvest. The risk assessment revealed that hazard quotient for the intake of mancozeb was in the range of 0.06-0.13% and 0.20-0.44% for rural and urban population, while for the intake of chlorpyrifos, hazard quotient was in the range of 0.10-0.12% for rural population and 0.33-0.38% for urban population, and theoretical maximum dietary intake (9.67 × 10-5 mg/person and 3.18 × 10-4 mg/person for rural population and urban population in case of mancozeb and 3.22 × 10-5 mg/person and 1.06 × 10-4 mg/person for rural population and urban population in case of chlorpyrifos) was also found to be less than maximum permissible intake (1.38 mg/kg for mancozeb and 0.60 mg/kg for chlorpyrifos). The results of risk assessment thereby indicated that apple consumption does not pose a risk to human health.

Synthesis and characterization of Ni0.5Al0.5Fe2O4 nanoparticles for potent antifungal activity against dry rot of ginger (Fusarium oxysporum).

Current study signifies the use of nanoparticles as alternative in plant disease management to avoid harmful effect of pesticide and fungicide residue. Synthesis of nanoparticles (Ni0.5Al0.5Fe2O4) by hydrothermal method and studied their X-ray diffraction analysis (XRD), Raman spectra, and UV spectra and further successfully evaluated for antifungal activity against a soil and seed borne pathogenic fungus (Fusarium oxysporum).Among various pests, fungal pathogens are the main cause of crop destruction and we developed nanoparticles (Ni0.5Al0.5Fe2O4) which is successfully evaluated for antimycotic activity against dry rot (F. oxysporum) of ginger which causes 50-70% losses in the ginger plant. In vitro and in vivo analysis designated that the nanoparticles (Ni0.5Al0.5Fe2O4) has shown an excellent antifungal activity against F. oxysporum at 0.5 mg/ml concentration. Similarly, no disease incidence was recorded when Ni0.5Al0.5Fe2O4 nanoparticles used at 0.5 mg/ml concentration under in vivo conditions. In plants various environmental stresses (biotic and abiotic) leads to excessive production of reactive oxygen species (ROS) causing progressive oxidative damage and ultimately leads to cell death. The role of ROS in nanoparticles (Ni0.5Al0.5Fe2O4) represents by reduction in the growth inhibition of F. oxysporum. We speculated in light of these results that the cytotoxic effect of Ni0.5Al0.5Fe2O4 nanoparticles on F. oxysporum may be mediated through ROS. We can suggest the role of nanoparticles (Ni0.5Al0.5Fe2O4) gives a promising result as a fungicidal activity and could be a novel family of future new generation fungicide.

Dissipation pattern and dietary risk assessment of some commonly used insecticides on tomato (Solanum lycopersicum L.).

Pesticide residue in food commodities is a serious concern in relation to consumer safety and also the most significant barrier in the trade of food commodities. The dissipation pattern of four insecticides, namely novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin, was evaluated on tomato fruits and cropped soil. The residues were extracted using the QuEChERS analytical method and quantized using a gas chromatograph with electron capture detector, gas chromatograph mass spectrometer, and high-performance liquid chromatography with photo diode array detector. The analytical method was validated using parameters like recovery, linearity, accuracy, matrix effect, and specificity, with limit of detection and limit of quantitation established to be 0.01 and 0.05 mg/kg, respectively, for all the pesticides. The average initial deposits (samples collected after 2 h of application) at the recommended dose of novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin were 0.593, 0.293, 0.227, and 0.431 mg/kg on tomato fruits, respectively, and were below the limit of quantification in soil. The pre-harvest interval of 17, 8, 1, and 13 days was suggested for novaluron, λ-cyhalothrin, imidacloprid, and fenazaquin on tomato, respectively. Risk assessment studies revealed that all pesticides under study are safe and do not pose any threat to humans as theoretical maximum dietary intake is less than the maximum permissible intake and acceptable daily intake.