Pesticide Penetration Research Articles

Evaluation of Fermented Plant Extracts as Bioinsecticides in Controlling Phenacoccus solenopsis Colonies on Hibiscus rosa-sinensis under Laboratory Conditions

The mealybug, Phenacoccus solenopsis, is a serious pest of Hibiscus rosa-sinensis. The waxy coating on its body may hinder pesticide penetration, and the extensive use of pesticides is risky to humans and the environment. Considering these drawbacks, fermented plant extracts (FPEs) were explored for their potential use in controlling this pest in a more user and environmentally-friendly manner. FPEs derived from eleven plant materials were evaluated against P. solenopsis for their insecticidal activity, mealybug wax removal potential and phytotoxicity effect on H. rosa-sinensis. Five concentrations of FPE [5, 10, 15, 20, and 25% (w/v)] were prepared. Among the 11 FPEs, FPE derived from ficus, kaffir lime, and turmeric were effective in suppressing P. solenopsis with lethal concentration at 50% (LC50 value) less than 20% concentration. Although ficus FPE was the top performer in the insecticidal assay, it induced medium to very high levels of leaf damage after being treated with 15–25% concentration at 24 and 72 hr post-treatment. A low level of leaf damage was observed in treatment with turmeric and kaffir lime FPEs at 72 hr post-treatment. FPEs could remove wax from the body of P. solenopsis with no significant difference among them. In conclusion, the FPE of ficus, kaffir lime, and turmeric showed promising insecticidal effects against P. solenopsis.

Combining LAESI Imaging and Tissue Spray Ionization Mass Spectrometry To Unveil Pesticides Contaminants in Fruits.

There is an increasing need for developing a strategy to analyze the penetration of pesticides in cultures during postharvest control with minimal or no sample preparation. This study explores the combined use of laser ablation electrospray ionization mass spectrometry imaging (LAESI imaging) and tissue spray ionization mass spectrometry (TSI-MS) to investigate the penetration of thiabendazole (TBZ) in fruits, simulating a postharvest procedure. Slices of guava and apple were prepared, and an infrared laser beam was used, resulting in the ablation of TBZ directly ionized by electrospray and analyzed by mass spectrometry. The experiments were conducted for 5 days of fruit storage after TBZ administration to simulate a postharvest treatment. During postharvest treatment, TBZ is applied directly to the fruit peel after harvesting. Consequently, TBZ residues may remain on the peel if the consumer does not wash the fruit properly before its consumption. To evaluate the effectiveness of household washing procedures, TSI-MS was employed as a rapid and straightforward technique to monitor the remaining amount of TBZ in guava and apple peels following fruit washing. This study highlights the advantages of LAESI imaging for evaluating TBZ penetration in fruits. Moreover, the powerful capabilities of TSI-MS are demonstrated in monitoring and estimating TBZ residues after pesticide application, enabling the comprehensive unveiling of pesticide contaminants in fruits.

Bacteria, Fungi, and Enzymes in Soil Treated with Sulcotrione and Terbuthylazine.

Soil's biological equilibrium, disturbed by the uncontrolled penetration of pesticides, can be restored by the activity of native microorganisms, which show abilities in neutralizing these xenobiotics. Therefore, this research is necessary in the search for new microorganisms used in the process of the bioremediation of contaminated soils. The aim of this study was to evaluate the effects of the herbicides, Sulcogan 300 SC, Tezosar 500 SC, and Sulcotrek 500 SC, applied to soil at the manufacturers' recommended dosage as well as 10-fold higher, on the abundance of microorganisms, the diversity and structure of bacterial and fungal communities, the activity of soil enzymes, and the growth and development of Zea mays L. It was found that herbicides in contaminating amounts stimulated the proliferation of organotrophic bacteria and inhibited the growth of fungi. Organotrophic bacteria and actinobacteria were represented by K-strategies and fungi by r-strategies. Bacteria belonging to the phylum, Actinobacteriota, represented by the genus, Cellulosimicrobium, were most abundant in the soil, while among the fungi, it was the phylum, Ascomycota, represented by the genus, Humicola and Chaetomium. The herbicides decreased urease activity while increasing arylsulfatase and acid phosphatase activity. They had a positive effect on the growth and development of Zea mays L., as evidenced by an increase in the values of the plant tolerance index (TI) and the maize leaf greenness index (SPAD). The results indicate that soil microorganisms and enzymes are suitable indicators reflecting the quality of herbicide-treated soil.

Assessment of the Barrier Performance of the Flourosilicone Treated Fabric Exposed to Pesticides Spraying to Chilli Crop at Laboratory Conditions

In this study, in view of development of protective clothing for pesticide sprayers in chilli crop, the suitable fabric polyester 67/cotton 37 with weight 157.7 GSM was selected. BOND-WR-12-A RTU was aqueous fluorosilicone durable water and oil repellent emulsion was used to treat the fabric by using different application parameters at the rate of 5 per cent concentration. As per Chowdhury, 2018 water repellent finish type and concentrations were very important parameters to obtain water repellent fabric having acceptable use properties. Later, the treated fabric was exposed to the selected pesticides like Phosphamidon, Monocrotophos and Dimethoate for for three exposures. By estimating the absorption and penetration behaviour of the treated and untreated fabrics, the performance of silicon finish was determined by using four factor with CRD and Heuristic method. From this result, the treated fabric had restricted the absorbency over control fabric and the Studies on barrier clothing, [1,2] suggested that blends of polyester cotton and polyester viscose showed better barrier performance with minimum penetration of pesticides than other blended fabrics. Hence it can be used in development of protective clothing for pesticide applicators in chilli crop or any other field crops where ever pesticides are used.

Uptake, Translocation, and Terminal Residue of Chlorantraniliprole and Difenoconazole in Rice: Effect of the Mixed-Application with Adjuvant

Plant oil adjuvants are widely used to improve the utilization rate of pesticides. In this study, the uptake, translocation, and terminal residue of chlorantraniliprole and difenoconazole spraying with plant oil adjuvant in rice (Oryza sativa L.) were evaluated. After being mixed with the tank-mixed plant oil adjuvant, the cuticular wax of rice leaf was destroyed, which decreased the hydrophobicity of the rice leaf and facilitated the wetting, spreading, and penetration of pesticides onto the rice leaf. Additionally, the adjuvant promoted the translocation of difenoconazole from leaves to stems, but had little effect on the translocation of difenoconazole from leaves to roots, while inhibiting chlorantraniliprole translocation. Although adjuvant increased the initial deposition of chlorantraniliprole and difenoconazole on rice, the terminal residue was not significantly affected. The findings can promote the safe use of chlorantraniliprole and difenoconazole in rice production, especially when used with plant oil adjuvants. In the future, studies on more rice cultivars will be necessary to determine the generality of the conclusions.

USING OF CALCULATION MODELS OF THE PENETRATION OF SUBSTANCES THROUGH THE SKIN IN THE ASSESSMENT OF THE RISK OF DERMAL INFLUENCE OF PESTICIDES ON WORKERS.

The aim: Quantitative characterization of parameters of penetration of pesticides through the skin and assessment of the risk of their dermal exposure to workers using the basic provisions of diffusion theory and calculation models. Materials and methods: The penetration coefficient was calculated using the Potts's and Guy's equation: logKp,m = -2,8 - 6,0×10-3MW + 0,74logKo/w (R2 = 0.67). Determination of the absorbed dose was carried out using the maximum flow of the substance per unit area and the area of contact of the pesticide with the skin. Calculations were performed using the Microsoft Excel 2010 computer program package, PubChem information databases, EU Pesticides Database. Results: It was established that the pyrethroid insecticide bifenthrin and triazole fungicides (prothioconazole, propiconazole, and tebuconazole) penetrate the skin the fastest among the studied substances. The highest value of the absorbed dose is observed in the case of bifenthrin, which creates dangerous conditions during production operations with pesticide formulations based on it and conditions the adoption of necessary management decisions. Conclusions: The calculation model of Potts and Guy (1992) is sufficiently informative and reliable to determine the coefficient of penetration of pesticides from aqueous solutions in the phase of the steady process of diffusion and allows determining the doses absorbed through the skin and assessing the risk of dermal exposure to workers.

과수재배 농업인을 위한 기능성 농약 방제복 개발 및 평가

This study sought to develop pesticide-protective clothing, which could reduce pesticide exposure and enhance work comfort for fruit farmers. The use of pesticides in fruit tree cultivation has increased agricultural productivity. However, with the high frequency of pesticide spraying, there is the possibility of agricultural chemical poisoning, which could affect the health of the farmers. In this study, the functional material used to make pesticide-protective clothing was examined and its physical properties were evaluated. A sensory evaluation on the pesticide-protective clothing material was then conducted and its physiological comfort was also evaluated. According to the study results, the applied material met the pesticide penetration prevention standards, and the pesticide-protective clothing offered a satisfactory fit. According to the comfort wear test results, the temperature and humidity inside the clothing were lower than that of existing pesticide-protective clothing and it was thus found to be effective in reducing heat stress and enhancing comfort compared to the existing products (p0.05). In the future, there would be a need to develop pesticide-protective clothing more suitable for the fruit tree cultivation working environment based on a field applicability evaluation. The results of this study are expected to contribute to the design of pesticide-protective clothing for farmers.

Real-time and in situ monitoring of organosilicon-induced thiram penetration into cabbage leaves by surface-enhanced Raman scattering mapping.

Understanding pesticide penetration behavior is important for effective application of pesticides. However, there is a lack of an effective method to monitor pesticide penetration behavior and its changing process. In the present study, a novel surface-enhanced Raman scattering (SERS) mapping method was used for real-time and in situ tracking of the penetration behaviors of thiram and thiram-organosilicon mixture on cabbage leaves. The results suggest that thiram has very weak ability to penetrate into cabbage leaves. However, when the thiram-organosilicon mixture was placed on leaf surfaces, a clear thiram signal was detected inside the leaf after 2 h of exposure, a strong signal was observed after 12 h, and the penetration depth of thiram was approximately 200 μm after 48 h. SERS mapping was demonstrated to be a reliable method for in situ monitoring of organosilicon-induced thiram penetration into cabbage leaf over time. The present study provides a new reference for rationally selecting adjuvants, effectively applying pesticides, and reducing pesticides residue in food. © 2022 Society of Chemical Industry.

Application of an Adsorption Process on Selected Materials, Including Waste, as a Barrier to the Pesticide Penetration into the Environment.

The article presents research on using the adsorption process of aldrin (a chloro-organic pesticide that most often occurs in the environment near expired pesticide burials). The research used three sorbents: two activated carbons and compost from sewage sludge as a low-cost sorbent. Obtained adsorption isotherms belong to the L group according to the Giles classification. The test results and their analysis confirm that the IZO application facilitates the analysis of the adsorption process. The study results also confirm that compost can be a cost-effective alternative to commercial activated carbons to build barriers protecting the environment against existing leaking expired pesticide burials.

Design and Test of a Jet Remote Control Spraying Machine for Orchards

Aimed at issues associated with the poor air supply and poor automatic targeting accuracy of existing orchard sprayers, this paper designs a jet-type orchard remote control sprayer with automatic targeting which is suitable for standardized orchards in hilly and mountainous areas. By optimizing the structure of the diversion box, the uniformity of deposition and penetration ability of the pesticide droplets to the fruit tree canopy are improved, and a uniform wild field distribution is realized simultaneously. An accurate positioning of the fruit tree canopy space orientation is achieved through automatic targeting and azimuthal adjustment systems. When the target is detected, the solenoid valve is controlled to open, and vice versa, and the distance from the nozzle to the fruit tree canopy is adjusted in real time to improve the utilization rate of pesticides. The test results show that the effective range of the jet-type orchard remote control sprayer is no more than 3.5 m, and the maximum flow rate range is 6~6.5 L/min. Within the effective spraying range, the farther the distance is, the higher the automatic targeting accuracy. The pesticide droplets sprayed by the spraying machine have a certain penetration ability, and the uniformity of the droplets is good, which solves solidification problems caused by the penetration of pesticide into the soil. This research provides a reference for jet spraying operation and automatic targeting spraying structure design.

Spatiotemporal Visualization of Insecticides and Fungicides within Fruits and Vegetables Using Gold Nanoparticle-Immersed Paper Imprinting Mass Spectrometry Imaging.

Food safety issues caused by pesticide residue have exerted far-reaching impacts on human daily life, yet the available detection methods normally focus on surface residue rather than pesticide penetration to the internal area of foods. Herein, we demonstrated gold nanoparticle (AuNP)-immersed paper imprinting mass spectrometry imaging (MSI) for monitoring pesticide migration behaviors in various fruits and vegetables (i.e., apple, cucumber, pepper, plum, carrot, and strawberry). By manually stamping food tissues onto AuNP-immersed paper, this method affords the spatiotemporal visualization of insecticides and fungicides within fruits and vegetables, avoiding tedious and time-consuming sample preparation. Using the established MSI platform, we can track the migration of insecticides and fungicides into the inner region of foods. The results revealed that both the octanol-water partition coefficient of pesticides and water content of garden stuffs could influence the discrepancy in the migration speed of pesticides into food kernels. Taken together, this nanopaper imprinting MSI is poised to be a powerful tool because of its simplicity, rapidity, and easy operation, offering the potential to facilitate further applications in food analysis. Moreover, new perspectives are given to provide guidelines for the rational design of novel pesticide candidates, reducing the risk of food safety issues caused by pesticide residue.

How to protect agricultural workers from exposure to pesticides: Effectiveness of woven and natural resin-coated fabrics

Agricultural workers in low and middle-income countries usually wear their everyday clothing made of woven fabrics during pesticide application. Different characteristics of various woven fabrics have different abilities to prevent the penetration of pesticides through to the skin. Therefore, the ultimate goal of this study is that agricultural workers in Thailand can choose a suitable fabric of protective clothing to protect themselves from pesticide exposure. This study aims to investigate pesticide penetration levels in different woven fabrics, and to explore factors affecting levels of pesticide penetration through fabrics. In addition, our study aims to produce cotton fabrics coated with a natural resin to obtain water-repellent characteristics and evaluate their effectiveness in protecting against pesticides. Four pesticides used in the testing process were chlorpyrifos, cypermethrin, paraquat, and glyphosate. The results found that a suitable fabric to protect agricultural workers from pesticide exposure is a fabric which made of 100% cotton and have greater weight. With regard to natural resin-coated fabrics, fabric C1-R showed the highest levels of effectiveness in protecting against the pesticides (range between 89%-95%). The natural resin-coated fabric is an alternative fabric in the protection against pesticides for agricultural workers in low and middle-income countries when commercial PPE are prohibitively expensive.

Occupational Health: Farmers Knowledge on Pesticide usage and it�s Harmful Effects on Human Health in Rural Areas of South India

An estimated 1.3 billion workers are engaged in agricultural production worldwide. This represents half of the total world labor force. Almost 60% of them are in developing countries. Pesticides can enter the human body by three common ways: Through the skin (contact), the mouth (ingestion) and the lungs (inhalation). The state of the chemical, i.e. solid, liquid or gas, affects the chances of pesticide penetration into the body. During the usage of pesticides farmers reported problems such as eye irritation, headache, dizziness, breathing difficulty, skin rashes and all of these symptoms at least once during their exposure to pesticides. A field based cross sectional study was conducted in the rural areas of Karnataka state, Gadag district, to assess the farmer’s knowledge, attitudes and practices about pesticide usage and its harmful effects on human health. A pre-tested semi-structured questionnaire was used to obtain the data from January to February 2020. Data was collected at the rural settings by visiting their house and agriculture fields. Totally 265 farmers were interviewed, out of that more than half of them have good knowledge about pesticide usage but only few of them have knowledge about the harmful effects of pesticide on their health. In our study findings majority of the farmers are not aware about the health hazards due to usage of pesticides, they showed good attitude and poor practices about pesticide usage.

АНАЛІЗ ХІМІЧНИХ ЗАГРОЗ ЕКОЛОГІЧНІЙ БЕЗПЕЦІ ВІННИЦЬКОЇ ОБЛАСТІ

The main threats to the environmental safety of Vinnytsia and Vinnytsya oblast in the field of the use and storage of pesticide and chemical wastes are presented in this work. The analysis of threats to ecological safety from pesticides, which consist of pesticide-contaminated soils, compositions and places of storage of pesticides and contaminated groundwater. The data of the Department of Agricultural Development, Ecology, and Natural Resources of Vinnytsia Oblast State Administration is presented, and it was analyzed how effective the cleaning of the territory of Vinnytsia Oblast was from the non-standard CWCP, and which components of this problem remain relevant and dangerous. It was established that four districts can be considered as cleared from the remains of unsuitable pesticides, in particular, Vinnytsia, Lipovetsky, Nemyrivsky, and Khmelnytsky, while in the Teplitsky, Tyvrivsky and Shargorodsky districts the situation with unsuitable pesticides is critical. In recent years, the process of export of pesticides abroad has been stopped due to significant costs, but work on inventory and re-stocking is constantly taking place. During the inventory of pesticides, new places of storage of non-conforming pesticides are detected. In addition to pesticides, there are an industrial waste on the territory of the region, which also creates chemical threats to environmental safety. These include waste from the 45th experimental plant, Khimprom, Plant Oreol, Terminal Plant, and others. The chemical classification of pesticides is given and according to the statistics, the most widely used in Ukraine are chlorinated and phosphorous pesticides. Among the most chemically dominated regions, the leaders are Vinnytsya, Khmelnytsky and Kirovograd regions in 2018. The methods of penetration and penetration of pesticides into soils are given and the main ways of their restoration and reclamation are analyzed. Among the most optimal methods of restoration is the removal of heat treatment and biological reclamation with phytomelioration. It is suggested to use strains of microorganisms: Agrobacterium radiobacter, Pseudomonas sp., Bacillus sp., Pseudomonas sp., Micrococcus sp., Proteus sp., Xanthomonas sp., Ankistrodesmus falcatus, A. nannoselene, Selenastrum capricornutum, and plants are able to reduce the toxicity of pesticides: ordinary beans and one-year sunflower.

Spray of Chemicals as Affected by Different Parameters of Air Assisted Sprayer: A Review

In orchards, day by day productivity reduces by diseases. To prevent the effect of these diseases, spraying of pesticide was one of the options. There were several methods for pesticide spraying, one of the efficient method practiced in spraying by air assisted sprayer, which reduced losses during spraying and cover more tree canopy area. In this sprayer, different parameters were affecting spraying such as blower speed, operating speed of sprayer, operating pressure in sprayer and pesticide applications. Therefore the study was conducted to find out the effect of different parameter on spraying. The operating speed of sprayer showed significant effect on spray droplets deposition, distribution by conspicuously greater at lower operating speed. In air assisted sprayer, increasing blower speed significantly increased drift force and increased tree canopy area in spraying. The efficiency of spray deposition increased with increase in blower speed. The conveying efficiency of spray particles, penetration and distribution of pesticide were increased with increase in operating pressure. The performance of sprayer was found better with increase in operating pressure (1 to 15 kg/cm2) of spraying.

Spray Penetration and Natural Enemy Survival in Dense and Sparse Plant Canopies Treated with Carbaryl: Implications for Chemical and Biological Control1

Abstract Ornamental plant producers often rely on chemical control to manage insect pests. However, cultural practices, such as pruning, can influence plant architecture which may, in turn, affect pesticide penetration. Spray penetration was studied to determine the effect of canopy density on beneficial insect survival following insecticide application and to better understand the implications of canopy density on pest management. Regardless of canopy density or plant species, the interior position of the canopy received less than 8% spray coverage. The middle position of sparse canopies received 288 to 513% more coverage than the middle position of dense canopies. The middle and interior position of dense canopies protected greater than 50% of the convergent lady beetle (Hippodamia convergens (Guérin-Méneville) population while only the interior position of dense canopies protected greater than 50% of green lacewing (Chrysoperla rufilabris Burmeister) populations. Index words: beneficial insect, nursery crop, pesticide, plant architecture, woody ornamental. Species used in this study: China Girl® holly (Ilex ×meserveae ‘Mesog'); ‘Alice' Oakleaf hydrangea (Hydrangea quercifolia Bartr. ‘Alice'); convergent lady beetle [Hippodamia convergens (Guérin-Méneville)]; green lacewing [Chrysoperla rufilabris (Burmeister)]. Chemicals used in this study: carbaryl (1-naphthyl N-methylcarbamate, Sevin® SL, Bayer CropScience, Durham, NC).

Aerodynamic performance optimization for the rotor design of a hovering agricultural unmanned helicopter

The importance of using Agriculture unmanned helicopters (AUHs), especially for spraying pesticides and fertilizers on any terrain type to ensure crop yields, has been recently acknowledged. Apart from flying these helicopters at a super-low altitude and low speed, using an efficient and optimum rotor blade ensures a uniform and deep penetration of pesticide and fertilizers over a specified area. Accordingly, this work attempts to optimize the rotor blade of an AUH by using coupling statistics and several numerical techniques, including design of experiments, response surface method, and computational fluid dynamics. The experiments are designed using the central composite design method and by selecting the geometric variables that affect the aerodynamic performance of the rotor blade, including the root chord, tip chord, and angle of attack. The angle at the root and tip is optimized in order for the resulting twist to produce a uniform blade loading, achieve maximum lift, and minimize the required hover power. The required aerodynamic forces and limited availability of engine power are identified as constraints. The blade is optimized only when the helicopter is hovering at a persistent rotational speed, and the hover efficiency of the rotor blade with an optimal twist distribution is significantly higher than the baseline.

In Silico Prediction for Intestinal Absorption and Brain Penetration of Chemical Pesticides in Humans.

Intestinal absorption and brain permeation constitute key parameters of toxicokinetics for pesticides, conditioning their toxicity, including neurotoxicity. However, they remain poorly characterized in humans. The present study was therefore designed to evaluate human intestine and brain permeation for a large set of pesticides (n = 338) belonging to various chemical classes, using an in silico graphical BOILED-Egg/SwissADME online method based on lipophilicity and polarity that was initially developed for drugs. A high percentage of the pesticides (81.4%) was predicted to exhibit high intestinal absorption, with a high accuracy (96%), whereas a lower, but substantial, percentage (38.5%) displayed brain permeation. Among the pesticide classes, organochlorines (n = 30) constitute the class with the lowest percentage of intestine-permeant members (40%), whereas that of the organophosphorus compounds (n = 99) has the lowest percentage of brain-permeant chemicals (9%). The predictions of the permeations for the pesticides were additionally shown to be significantly associated with various molecular descriptors well-known to discriminate between permeant and non-permeant drugs. Overall, our in silico data suggest that human exposure to pesticides through the oral way is likely to result in an intake of these dietary contaminants for most of them and brain permeation for some of them, thus supporting the idea that they have toxic effects on human health, including neurotoxic effects.

방제복에 대한 농약의 체류성, 발수성 및 침투성 측정

방제복에 대한 농약의 체류성, 발수성 및 침투성 측정

Loss of effectiveness of protective clothing after its use in pesticide sprays and its multiple washes

ABSTRACTProtective clothing is used as a barrier against pesticides when working with agricultural sprays. The aim of this study was to evaluate the pesticide penetration, retention, and repellence of the material and seams of a whole-body protective garment used by applicators of pesticides. The efficiency of the material and seams of the whole-body garment were determined for its classification as proposed by ISO 27065 (ISO, 2011). The evaluation method used was the pipette test of ISO 22608. The efficiency of the material and seams of the garment (100% cotton) were tested by contamination with formulations of Roundup Original® SL; Nufos EC® and Supera SC®. The presence of the seams in the protective clothing reduced its efficiency in the control of dermal exposure, except when protecting against the Supera SC® formulation. The number of washes and uses affected the efficiency of the material and seams of the garment. The type of formulation interfered significantly in the penetration of pesticides into the material and seams. Thus, the laboratory efficiency assessment of protective clothing is necessary to determine what types of formulations and use conditions are appropriate for workers.