Increase In Pesticide Concentration Research Articles

Status of Pesticide Use among Thyme (Thymus vulgaris) Crop Farmers in North West Bank, Palestine

The data were collected to diagnose the current status of pesticide use on thyme crops (Thymus vulgaris). In total, 111 questionnaires were used to calculate the means, standard deviation, and percentages of farmers’ responses. Chi-square (χ2) and T-tests were employed to test the associations between pesticide application practices and demographic variables, recipients of extension, sources of farmer information, production, and marketing. The results showed that 69.7% of farmers used 23 insecticides, and 11.8% of the pesticides were not suitable for pest control. Additionally, 73.5% were not compatible with the safety period. There was a 29.2% increase in pesticide concentration from the recommended amount and a 32.4% increase in the number of spraying times during the season. Farmer commitment to pesticide use instructions was moderate, with a mean of 2.8 ± 0.68. In total, 51.4% of farmers received extension services, and 47.2% relied on their local experience for pesticide practices. Extension services influenced the overused dose. Most farmers did not participate in specialized courses or field days, and no regulatory extension was carried out by institutions for them. They did not adhere to a production guide or obtain a quality certificate. The application of different pesticides did not increase the productivity of thyme. The study findings revealed alarming trends in current farmer practices, with significant implications for crop, farmers, and consumer safety. They underscore the pressing need for targeted interventions, including improved extension services and increased farmer awareness to promote responsible pesticide use.

The Toxicity of Imidacloprid on Early Embryonic Stages and Growth Rate of Hatchlings of Common Carp, <i>Cyprinus carpio</i>

In the present investigation, the toxicity of imidacloprid was tested on the embryos (fertilized eggs) and hatchlings of Cyprinus carpio in terms of mortality (%), hatching success (%) and abnormal/malformed hatchling along with their growth performance in toxicant medium. Reported data from acute toxicity tests of imidacloprid was statistically analyzed by Probit Analysis Method and 48 h (hour) LC50 was reported as 78 ppm for embryos of C. carpio. Three sublethal doses of imidacloprid i.e., 7.8 ppm (T1), 15.6 ppm (T2) and 23.4 ppm (T2), were selected for further experimentation along with control. The findings revealed that mortality of exposed eggs (%) was significantly (p<0.05) increased in dose dependent manner as a result hatching rate (%) was decreased as compared to control. Similarly, per cent of abnormal hatchling was also increased significantly (p<0.05) with increase in pesticide concentration. Various types of abnormalities has been reported in different body regions such as whole length curved body, stunted growth, hatchling with single eye, malformed head, flexure in the tail and deformed yolk sac etc. Growth rate was observed as length gain in centimeter (cm), weight gain in grams (g) and growth per cent gain in body weight of hatchling, which was also found to be declined significantly (p<0.05) with increase in pesticide concentration. The findings of the present investigation suggest that imidacloprid has significant effect on the early developmental stages, induces malformations and also decline the growth rate of hatchlings.

Improving pesticide uptake modeling and management in potatoes: A simple and approximate phloem-adjusted model

To evaluate the impact of the phloem flux on the pesticide uptake process in potatoes, this study developed a phloem-adjusted model based on the classic model that focuses mainly on the diffusion process. To achieve high-throughput simulations, we introduced an approximate method to convert the phloem flux transport process into a simple specific uptake rate of pesticides. In comparison to the classic model (non-phloem model), the phloem-adjusted model generated higher pesticide concentrations and bioconcentration factors (BCFs) in potatoes, owing to the additional pesticide uptake route introduced to the adjusted model. However, the simulation, which was conducted for 740 pesticides, indicated that for most pesticides, the phloem flux route did not contribute a significant portion of the pesticide uptake to potato tubers compared with the soil diffusion route. This was further characterized, using the differential factor (DF), to evaluate the difference in the simulated results between the proposed model and classic models. The largest DF (~0.11) was obtained for pesticides with moderate lipophilicity (i.e., log KOW of 3.0), indicating that only a difference of 10% was generated between the two models. The 10% increase in pesticide concentration (or BCFs) in potatoes, simulated by the phloem-adjusted model, was within the acceptable uncertainty interval of the classic model, thus confirming the validity of using the classic model to predict the pesticide uptake process in potato tubers. However, we found that the negligibility of the phloem flux route was not merely due to hydrophobicity (i.e., hypothesis of the classic model), but was related to the i) plant physiology of potatoes, ii) lipophilicity of a pesticide, and iii) the diffusivity of a pesticide in water. Although future studies on pesticide concentrations in phloem sap and the dynamic growth of potatoes need to be undertaken, the model developed in this study reveals a more comprehensive pesticide uptake process in potatoes, which can promote the understanding of the pesticide uptake mechanism in potatoes.

A terahertz multi-band metamaterial absorber and its synthetic evaluation method based on multivariate resonant response fusion for trace pesticide detection

A synthetic multivariate response evaluation of a multi-band terahertz (THz) metamaterial absorber (MMA) for highly sensitive and accurate detection of trace pesticides including indole-3-acetic acid, thidiazuron, benomyl, and chlorpyrifos in solution is presented. The THz spectral response of the prepared MMA sensor illustrated that with an increase in pesticide concentration (10∼520 ng/L), all absorption bands (0.91, 1.59, 1.99, and 2.42 THz) exhibited a red-shift in frequency, part of which showed a decrease in absorption intensity. The modeling results between the pesticide concentrations and spectral responses demonstrated that the proposed multivariate resonant response fusion (MRRF) framework outperformed all the univariate regressions in improving accuracy and simplifying evaluation through the effective multivariate selection and statistical fusion. The highest detection accuracy was achieved for chlorpyrifos (CPF). Consequently, trace CPF in four vegetable extracts was detected to further verify the stability and reliability of the multi-band MMA combined with MRRF. The results indicated that the predicted recoveries using our approach were accurate, and the detection limits of all pesticide solutions reached 10 ng/L. This work presents a new prospect for highly sensitive detection of trace hazardous materials and the potential application of THz metamaterial technology in food safety inspection.

Toxic effects of chlorpyrifos, cypermethrin and glyphosate on the non-target organism Selenastrum capricornutum (Chlorophyta).

The toxic effects of the insecticides chlorpyrifos and cypermethrin, and the herbicide glyphosate on the growth, biovolume and ultrastructure of the green microalgae Selenastrum capricornutum were evaluated. Concentrations between 9.37-150 mg L-1 of chlorpyrifos, 3.12-100 mg L-1 of cypermethrin and 4.7-60 mg L-1 of glyphosate were assayed along with a control culture. The assayed concentrations were prepared using commercial formulations. After 48 h all tested concentrations of the three pesticides reduced significantly the population growth. The 96 h effective concentration 50 (EC50) was 14.45 mg L-1 for chlorpyrifos, 12.37 mg L-1 for cypermethrin and 15.60 mg L-1 for glyphosate. Cells exposed to the three pesticides showed an increase in the cellular size related to the increase in pesticide concentration and exposure time. The most significant damages observed on the ultrastructure of cells exposed to the three pesticides included thylakoids and mitochondria disruption, formation of electrodense bodies, accumulation of lipids and increase in the size and number of starch granules. The present study demonstrates that the effects of pesticides also extend to non-target organisms having significant ecological implications.

Removal of multiple pesticide residues from water by low-pressure thin-film composite membrane

The study evaluated removal efficiency of 43 pesticides from water by thin-film composite polyamide membrane indigenously prepared by interfacial polymerization of 1,3-phenylenediamine and 1,3,5 trimesoyl chloride coated on asymmetric polysulfone support. Membrane performance was evaluated by gas and liquid chromatography mass spectroscopy determination of multiple pesticides remaining in feed and permeated water following the application of pesticides each @ 0.02, 0.05, and 0.10 mg/L in de-ionized water. The membrane was most efficient in the rejection of persistent organochlorine insecticides, viz. endosulfans (100%), dichlorodiphenyltrichloroethane (95%), and hexachlorocyclohexane (92%). Out of 43 selected pesticides, 33 were removed by > 80%. Size exclusion mass transfer played a significant role for molecules to pass through the membrane as observed for endosulfan isomers, endosulfan sulphate, and difenoconazole with molecular weight > 400. Pesticide rejection was also related to hydrophobicity (Log P). Hydrophobic pesticides with log P > 4.5 were rejected by > 80%, while monocrotophos with less hydrophobicity (log P = − 0.22) exhibited poor rejection (38%). Water flux decreased with an increase in pesticide concentration. The process of pesticide filtration was optimized at 200 psi. The results indicated the potential of the membrane to remove pesticides from water.

Pesticide application inhibit the microbial carbonic anhydrase-mediated carbon sequestration in a soil microcosm.

Heterotrophic system for carbon sequestration is gaining importance in the recent decades. Carbonic anhydrase (CA) is a major enzyme involved in carbon sequestration and biomineralization process. In this paper, we evaluate the effect of pesticide on CA activity using inhibitory assay. 2,4-D, being one of the most extensively used pesticide, being deleterious to soil health, its usage should be minimized to regain the soil health. Maximum inhibitory constant (Ki) was observed for 5% 2,4-D (49.53 mM) followed by 5% glyphosate (43.92 mM). The maximum Km increase with increase in pesticide concentration by 3.05-fold was in case of glyphosate which was higher than that of 2,4-D (2.08-fold) and dichlorvos (2.38-fold). Moreover, we evaluated the carbon sequestration using CA enzyme in the soil microcosm. In the present study, we identified the negative impact of 2,4-D on carbonic anhydrase produced by Bacillus halodurans PO15. The inhibition was a mixed type and had significantly lowered the carbon reduction to about 2.38 ± 0.17% in a soil microcosm study. Based on the molecular docking, the inhibition was contributed due to weak H-bonding interaction with amino acid residues (Gly65, Gly95, Val147, Ser150 and Gly65, Ser146, and Ser150).

Parameters affecting azoxystrobin and imidacloprid degradation in biobed substrates in the North Indian tropical environment

This study reports degradation of azoxystrobin (AZOXY) and imidacloprid (IMIDA) in the rice straw (RS)/corn cob (CC) and peat (P)/compost (C)-based biomixtures. The effect of biomixture preconditioning (10 days incubation prior to pesticide application), pesticide concentration and moisture content was evaluated. Results suggested that conditioning of biomixture greatly affected IMIDA degradation where half-life (t1/2) was reduced by 5–9 times. This was attributed to higher microbial biomass carbon content and dehydrogenase activity in the conditioned biomixtures. Pesticide application in the conditioned biomixture did not show any negative impact on soil microbial parameters. Both pesticides degraded at faster rate in the rice straw-based biomixtures than in the corn cob-based biomixtures. Degradation slowed down with increase in initial concentration of pesticides in biomixture and 1.6–3.0 (AZOXY) and 2.4–3.6 (IMIDA) times increase in t1/2 values was observed. The moisture content of biomixture showed positive effect on degradation which increased when moisture content was increased from 60 to 80% water holding capacity. The effect was significant for IMIDA degradation in the corn cob-based biomixtures and AZOXY degradation in the peat biomixtures. The rice straw-based biomixtures were better in degrading AZOXY and IMIDA and can be used in biopurification systems.

In vitro investigation to explore the toxicity of different groups of pesticides for an agronomically important rhizosphere isolate Azotobacter vinelandii

In this work, an attempt was made to evaluate the effect of pesticides on growth pattern, surface morphology, cell viability and growth regulators of nitrogen fixing soil bacterium. Pesticide tolerant Azotobacter vinelandii strain AZ6 (Accession no. MG028654) was found to tolerate maximum level of pesticide and displayed multifarious PGP activities. At higher concentrations, pesticides triggered cellular/structural damage and reduced the cell viability as clearly shown under SEM and CLSM. With increase in concentration, pesticides exhibited a significant (p < 0.05) decrease in PGP traits of strain AZ6. Among all three groups of pesticides, herbicides glyphosate and atrazine were most toxic. Kitazin, hexaconazole, metalaxyl, glyphosate, quizalofop, atrazine, fipronil, monocrotophos and imidacloprid at 2400, 1800, 1500, 900, 1200, 900, 1800, 2100 and 2700 μg mL−1, respectively, decreased the production of IAA by 19.5 ± 1.9 (61%), 18.1 ± 1.2 (64%), 36.4 ± 3.4 (28%), 13.1 ± 0.8 (74%), 15.6 ± 1.0 (69%), 7.6 ± 0.5 (83%), 11.9 ± 0.8 (76%), 24.7 ± 1.7 (51%) and 32 ± 2.3 (37%) μg mL−1, respectively, over control (50.7 ± 3.6 μg mL−1). A maximum reduction of 8.4 ± 1.2 (46%), 5.8 ± 0.6 (62%) and 4 ± 0.2 (74%) μg mL−1 in 2, 3-DHBA at 300 (1×), 600 (2×) and 900 (3×) μg mL−1 glyphosate, respectively, While, 32.8 ± 2.7 (19%), 27.2 ± 2 (33%) and 21.5 ± 1.3 (47%) μg mL−1, respectively in the production of SA was observed at 300 (1×), 600 (2×) and 900 (3×) μg mL−1 atrazine, respectively. Likewise, with increase in concentration of pesticides, decrease in P solubilization ability and change in pH of broth was detected. The order of pesticide toxicity to PSE (percent decline over control) at highest concentration was: atrazine (45) > kitazin (44) > metalaxyl (43) > monocrotophos (43) > glyphosate (41) > hexaconazole (39) > quizalofop (33) > imidacloprid (31) > fipronil (25). The present study undoubtedly suggests that even at higher doses of pesticides, A. vinelandii maintained secreting plant growth regulators and this property makes this strain agronomically important microbe for enhancing the growth of plants.

Reductive transformation of profenofos with nanoscale Fe/Ni particles.

Profenofos is an abundantly used organophosphate pesticide in agriculture but its excessive use may lead to hazardous effects on environment. Thus, the present study focused on the reductive transformation of this pesticide in the presence of Fe/Ni bimetallic nanoparticles by optimizing the process parameters such as stirring time, nanoparticles dose, pH, and initial pesticide concentration. The results of reductive transformation were compared with photodegradation studies. It was found that with the increase in UV irradiation time, the percent degradation was increased. After 660min, a 78% photodegradation of 100μM solution of pesticide was observed. On increasing the initial pesticide concentration to 200μM, the maximum degradation was achieved in 570min, but here, only 73% degradation was observed. The rates of photodegradation observed with 100 to 400μM solutions were 1.4 × 10-3, 1.5 × 10-3, 1.5 × 10-3, and 5 × 10-4min-1 respectively.In case of reductive transformation carried out in the presence of Fe/Ni bimetallic nanoparticles, the degradation was observed to be increased from 78 to 93.9% in only 180min. A further increase in pesticide concentration led to a decrease in degradation. Under these conditions, the rate of reaction was found to be 1.09 × 10-2min-1. A 93% degradation of profenofos was further increased to 98% when the quantity of nanoparticles was increased twice; hence, a significant reduction in time of irradiation was observed. Reductive transformation of pesticide thus provided an efficient and cheaper method for reducing the burden of profenofos from the environment.

Characterization of pesticide sorption behaviour of slow pyrolysis biochars as low cost adsorbent for atrazine and imidacloprid removal

Agri-wastes biochars viz. eucalyptus bark (EBBC), corn cob (CCBC), bamboo chips (BCBC), rice husk (RHBC) and rice straw (RSBC) and acid treated RSBC (T-RSBC), were characterized for their physico-chemical properties and sorption behaviour of atrazine and imidacloprid was studied. Kinetics study suggested that except atrazine adsorption on RSBC, which was best explained by the pseudo second order model, sorption of atrazine and imidacloprid on biochars was well explained by the modified Elovich model. Among the five normal biochars, the RSBC showed the maximum atrazine (37.5–70.7%) and imidacloprid (39.9–77.8%) sorption. The phosphoric acid treatment of RSBC further enhanced the sorption of both pesticides in T-RSBC. The Freundlich adsorption isotherms were highly nonlinear and percent adsorption decreased with increase in pesticide concentration in solution. Pesticide adsorption on biochars was affected by their aromaticity, polarity, pore diameter, pH and weak acid fraction. Thus, rice straw biochars have great potential for environmental implications and can be exploited as adsorbents for pesticide industry spewed waste water purification.

Response of maize (Zea mays L. saccharata Sturt) to different concentration treatments of deltamethrin

The aim of this study was to investigate the effect of the deltamethrin pesticide on the biological properties of maize (Zea mays L. saccharata Sturt). Maize seeds were exposed to environmentally relevant dosages (0.01, 0.05, 0.1 and 0.5 ppm) of deltamethrin. On the 7th day of germination, morphological, anatomical and physiological responses were determined. All seedling growth characters were decreased with increasing deltamethrin levels. The most negative effect on the radicle length of maize was observed by the highest deltamethrin concentration with a 61% decrease (P < 0.05). Both stomatal density and stomatal dimension reduction were caused by increasing concentrations of deltamethrin. Moreover, the pigments like chlorophyll a, chlorophyll b, total chlorophyll and caretonoids decreased with the increase in deltamethrin concentration. Conversely, anthocyanin and proline content increased in parallel with deltamethrin concentration. As a result, all morphological traits and pigments except for proline and anthocyanin were significantly reduced with an increase in pesticide concentration, compared to control (P < 0.05).

Phytotoxicity of Profenofos 50% EC (curacron 50 EC) to Vigna radiata,L. seedlings: II. Studies on Biochemical Parameters

Profenofos 50% EC (curacron 50 EC) is a hazardous pesticide commonly used in agriculture is also an important contaminant of environment.Its presence in biological system has gained importance due to bioaccumulation in food chain. The phyto-toxic effect of profenofos wasassessed based on the biochemical parameters (Shoot and Root) of seedlings (Amino acids, Protein, Sugar, DNA and RNA) of the test species,Vigna radiata,L. The concentrations of pesticide chosen were based on EC50 and are in the range of 0.02, 0.05, 0.08, 0.1 and 0.2 % ofprofenofos. The biochemical parameters like Amino acid, Sugar, DNA and RNA were significantly reduced with increase in pesticideconcentration whereas Protein concentration increased with the profenophos treatment. The increase in amino acid was more pronounced inShoot of the seedlings than root.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12063 Int J Appl Sci Biotechnol, Vol. 3(1): 101-105

Chlorpyrifos degradation in a biomixture of biobed at different maturity stages

The biomixture is a principal element controlling the degradation efficacy of the biobed. The maturity of the biomixture used in the biobed affects its overall performance of the biobed, but this is not well studied yet. The aim of this research was to evaluate the effect of using a typical composition of Swedish biomixture at different maturity stages on the degradation of chlorpyrifos. Tests were made using biomixture at three maturity stages: 0d (BC0), 15d (BC15) and 30d (BC30); chlorpyrifos was added to the biobeds at final concentration of 200, 320 and 480mgkg−1. Chlorpyrifos degradation in the biomixture was monitored over time. Formation of TCP (3,5,6-trichloro-2-pyrinidol) was also quantified, and hydrolytic and phenoloxidase activities measured. The biomixture efficiently degraded chlorpyrifos (degradation efficiency >50%) in all the evaluated maturity stages. However, chlorpyrifos degradation decreased with increasing concentrations of the pesticide. TCP formation occurred in all biomixtures, but a major accumulation was observed in BC30. Significant differences were found in both phenoloxidase and hydrolytic activities in the three maturity stages of biomixture evaluated. Also, these two biological activities were affected by the increase in pesticide concentration. In conclusion, our results demonstrated that chlorpyrifos can be degraded efficiently in all the evaluated maturity stages.

Effect of insecticides alone and in combination with fungicides on nitrification and phosphatase activity in two groundnut (Arachis hypogeae L.) soils

The effect of selected pesticides, monocrotophos, chlorpyrifos alone and in combination with mancozeb and carbendazim, respectively, was tested on nitrification and phosphatase activity in two groundnut (Arachis hypogeae L.) soils. The oxidation of ammonical nitrogen was significantly enhanced under the impact of selected pesticides alone and in combinations at 2.5 kg ha(-1) in black soil, and furthermore, increase in concentration of pesticides decreased the rate of nitrification, whereas in the case of red soil, the nitrification was increased up to 5.0 kg ha(-1) after 4 weeks, and then decline phase was started gradually from 6 to 8 weeks of incubation. The activity of phosphatase was increased in soils, which received the monocrotophos alone and in combination with mancozeb up to 2.5 and 5.0 kg ha(-1), whereas the application of chlorpyrifos singly and in combination with carbendazim at 2.5 kg ha(-1) profoundly increased the phosphatase activity after 20 days of incubation, in both soils. But higher concentrations of pesticides were either innocuous or inhibitory to the phosphatase activity.

Study of Cypermethrin Cytogenesis effects on Human Lymphocytes Using In-Vitro Techniques

The Cytogenetic effects of Cypermethrin a synthetic pyrithroid insecticide was investigated on human lymphocytes cultured in-vitro. Utilizing the trypan blue dye exclusion technique assay the LC50 of cypermethrin was found to be 36 uM. Based on LC50 value, hypermethrin was found to be low toxic to lymphocyte culture. Cypermethrin showed an increase in the frequency of chromosomal aberrations and found to be significant. Karyotype analysis revealed more satellite associations and chromosomal breaks in cypermethrin treated samples. Low-doses of the pesticide also induced singlestrand breaks in the DNA as assessed by comet assay. The pesticide caused increase in the comet tail length with increase in pesticide concentration, implicating genotoxicity in somatic cells. It is concluded that In vitro assays could give important information of the mechanism of toxicity at low dosages and impact on genetic material of human origin

Effect Of Permethrin On Survival And Reproduction Of &lt;i&gt;Bulinus globosus&lt;/i&gt; Morelet 1868 And &lt;i&gt;Bulinus Truncatus&lt;/i&gt; Audouin 1827

The effects of permethrin on reproduction and survival of Bulinus globosus and Bulinus Truncatus are reported. Serial dilutons of the chemical were used in 96 h exposure tests on the molluscs, followed by postexposure maintenance in the laboratory for 8 weeks. There was significant decrease in oviposition with increase in pesticide concentration. There were significant differences between treatment-means for both egg mass and embryo counts for both species of molluscs. The F-LSD values at 5% alpha level for eggmass counts were 2.81 and 2.97 respectively for B. globosus and B. truncatus; 49.60 and 55.72 for the embryo counts in that order. The chemical did not produce an appreciable adverse effect on snail survival and longevity. Keywords: Perrnethrin, Fecundity, Survival, Bulinus globosus, Bulinus truncatusAnimal Research International Vol. 1 (2) 2004 pp. 110-112