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Background: The use of unmanned aerial vehicles (UAVs) for the application of plant protection products (PPPs) in paddy fields is becoming increasingly prevalent worldwide. Despite its growing usage, UAV spraying for rice pest control faces practical challenges, including limited canopy penetration, uneven deposition, and significant spray drift. This study investigated the impact of two tank-mix adjuvants, Wonderful Rosin (Adjuvant-1) and Tiandun (Adjuvant-2), at six volume concentrations, on the spray liquid's physicochemical properties, spray drift, plant deposition, and the biological efficacy of rice insecticides using a quadrotor UAV sprayer., Results: The physicochemical characteristics of the spray liquid influenced spray performance and biological efficacy. Incorporating Adjuvant-1 and Adjuvant-2 led to a decrease in surface tension and contact angle while increasing the viscosity of the spray solution. These alterations in surface tension and viscosity contributed to an optimized droplet size distribution, reduced spray drift, enhanced deposition uniformity and penetration, and improved control efficacy against the rice planthopper in UAV applications. The highest control efficacy was observed at a concentration of 0.5%, showing an improvement of 35.12% (Adjuvant-1) and 20.23% (Adjuvant-2) over applications without tank-mix adjuvant 7 days after treatment., Conclusion: The judicious selection of tank-mix adjuvants for UAV PPP applications can significantly enhance spray performance and biological efficacy in controlling rice insects. This study's findings offer valuable insights for integrating tank-mix adjuvants into UAV spraying applications. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

A pesticide exposure baseline for honey bees was compiled for two New England cropping systems, the native North American plant species consisting of lowbush blueberry ( Vaccinium angustifolium Aiton) and cranberry ( Vaccinium macrocarpon Aiton). More unique pesticide compounds were applied in blueberry than cranberry, but the numbers of pesticides discovered in trapped honey bee pollen were similar between the two crop systems. Not all pesticides found in pollen were the result of the applications reported by growers of either crop. When comparing residues, number of pesticides detected, total concentration, and risk quotient varied between the two crops. Also, blueberry was dominated by fungicides and miticides (varroacides) and cranberry was dominated by insecticides and herbicides. When comparing reported grower applications that were matched with detection in residues, the proportion of pesticide numbers, concentrations, and risk quotients varied by crop system and pesticide class. In most cases, pesticide residue concentrations were of low risk (low risk quotient) to honey bees in these crops. Estimation of decay rates of some of the most common pesticide residues under field conditions could aid growers in selection of less persistent compounds, together with safe application dates, prior to bringing in honey bees for pollination.

Risk perception and use of personal protective equipment (PPE) in pesticide use were studied in 109 farmers of northern Greece. Farmers differed in the levels of pesticide risk perception, with 26.6% showing very low and low levels, 34.9% showing moderate levels, and 38.5% showing high and very high levels. Pesticide risk perception was positively correlated with education and large cultivated area, but negatively with age and non-farming as a main profession. Most farmers (82.6%) showed adequate use of PPE (mostly face mask and gloves). The use of PPE was positively correlated with education and risk perception, but negatively with age and non-farming as a main profession. Farmers with high levels of risk perception used 1.3 and 2.6 times more PPE items than those with moderate and low levels of risk perception, respectively. High education was a positive predictor, whereas main profession other than farming was a negative predictor of PPE use.

Various health risk assessment models have been developed to evaluate occupational pesticide exposure in China. However, there has been limited investigation into the relationship between health risks and pesticide spraying in orchards. In this study, we analyzed pesticide exposure of applicators while spraying with a stretcher-mounted sprayer in orchards located in four different climatic regions. All garments' unit exposure (UE) demonstrated a right-skewed distribution, with gloves and shins accounting for the highest proportion of dermal pesticide exposure. We observed little difference in dermal and inhalation UE levels between apple and citrus orchards, except for pesticide exposure levels on wipes and faces. While 57% of the inhalation UE distribution variance was attributed to clustering and location effects, no significant differences were observed in dermal exposure levels. We evaluated the impact of different levels of protective clothing on pesticide exposure levels, according to applicators' working habits in China. Our findings revealed that improved levels of protection significantly reduced dermal exposure to pesticides, particularly when wearing gloves during spraying with a stretcher-mounted sprayer. Based on our empirical data, we utilized a simple random sampling model and an intercept-only lognormal mixed model to estimate dermal and inhalation exposure levels. The estimated dermal UE was accurate to within 3-fold with 95% confidence, and half of the estimated inhalation UE was acceptable according to the fold relative accuracy (fRA). Our established and verified statistics for dermal and inhalation UE can be utilized to evaluate the potential pesticide exposure to applicators during spraying in orchards with a stretcher-mounted sprayer., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Volatile organic compounds (VOCs) are considered as important precursors of ozone in the air, while the contribution of VOCs from pesticide application (PVOCs) to ozone production is unknown. Utilizing data from the Ministry of Agriculture and Rural Affairs of the People's Republic of China and ChinaCropPhen1km, this paper developed PVOC emission inventories with a resolution of 1 km for the main crops (rice, maize, and wheat) from 2012 to 2019 in China. The results revealed that pesticide application is an important VOC emission source in China. Specially, the PVOC emissions from the major grain-producing regions in June accounted for approximately 30% of the annual total PVOC emissions in the local regions. The simulation with the Weather Research and Forecasting Community Multiscale Air Quality model (WRF-CMAQ) indicated that the PVOC emissions increased the mean maximum daily 8-hour average (MDA8) ozone concentration across China by 2.5 ppb in June 2019. During the same period, PVOCs in the parts of North China Plain contributed 10% of the ozone formation. Under the comprehensive emission reduction scenario, it is anticipated that by 2025, the joint implementation of measures including reducing pesticide application, improving pesticide utilization efficiency and promoting solvent substitution will decrease PVOC emissions by 60% compared with 2019, thereby mitigating ozone pollution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction: In this study, we aimed to characterise exposure to pyrethroids, organophosphates, and tebuconazole through multiple pathways in 110 parent-child pairs participating in the CELSPAC-SPECIMEn study., Methods: First, we estimated the daily intake (EDI) of pesticides based on measured urinary metabolites. Second, we compared EDI with estimated pesticide intake from food. We used multiple linear regression to identify the main predictors of urinary pesticide concentrations. We also assessed the relationship between urinary pesticide concentrations and organic and non-organic food consumption while controlling for a range of factors. Finally, we employed a model to estimate inhalation and dermal exposure due to spray drift and volatilization after assuming pesticide application in crop fields., Results: EDI was often higher in children in comparison to adults, especially in the winter season. A comparison of food intake estimates and EDI suggested diet as a critical pathway of tebuconazole exposure, less so in the case of organophosphates. Regression models showed that consumption per g of peaches/apricots was associated with an increase of 0.37% CI [0.23% to 0.51%] in urinary tebuconazole metabolite concentrations. Consumption of white bread was associated with an increase of 0.21% CI [0.08% to 0.35%], and consumption of organic strawberries was inversely associated (-61.52% CI [-79.34% to -28.32%]), with urinary pyrethroid metabolite concentrations. Inhalation and dermal exposure seemed to represent a relatively small contribution to pesticide exposure as compared to dietary intake., Conclusion: In our study population, findings indicate diet plays a significant role in exposure to the analysed pesticides. We found an influence of potential exposure due to spray drift and volatilization among the subpopulation residing near presumably sprayed crop fields to be minimal in comparison. However, the lack of data indicating actual spraying occurred during the critical 24-hour period prior to urine sample collection could be a significant contributing factor., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Unmanned Aerial Spraying System (UASS) has emerged as an advanced, precise, and efficient tool for pesticide application in numerous nations in recent years. Despite this, there is a noticeable gap in research advocating viable, quantifiable methodologies for application parameter optimization. This investigation was primarily oriented toward identifying optimal UASS application parameters. It did so by exploring the effects of varying spray volumes and flight parameters on spray performance in a comprehensive manner, and by assessing the biological potency of aerial insecticide application against Rice Planthopper (RPH) using the optimal parameters, aided by two types of nozzles in rice field settings., Results: Increased spray volume increased the spray deposition. Working height impacted the distribution of spray deposition, with a higher working height leading to superior distribution uniformity. Both spray volume and working height were observed to influence spray deposition and its percentage in tandem. Upon factor analysis, the optimal parameters determined for rice at the heading stage were an application volume of 15.0 L·ha -1 , a working height of 2.0 m, and a driving speed of 5.0 m·s -1 . Under these parameters, the air-induction twin flat fan nozzle IDKT120-015 demonstrated approximately 5% higher spray deposition than the flat fan nozzle SX11001VS, albeit with inferior distribution uniformity. Both nozzle types achieved over 93.0% control efficacy against RPH using triflumezopyrim, persisting for up to 40 days post-treatment., Conclusion: This study furnishes invaluable insights and data for controlling rice planthopper via UASS pesticide application, contributing to the progress of modern intensive and sustainable agriculture. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

The application of pesticides is not simply delivering chemicals to the target area. It also involves considering the negative aspects and developing strategies to deal with them during the application process, to ensure the maximization of pesticides use efficiency and the maintenance of the ecosystem. Unmanned aerial vehicle (UAV) sprayers demonstrate unique advantages compared to traditional ground sprayers, particularly in terms of maneuverability and labor intensity reduction, showed great potential for chemical application in pest control. It is undeniable that there exist challenges in the practice of UAV spraying, such as higher potential risks of pesticide drift or pathogen transmission, uncertainty canopy deposition for different crops, and unexpected leaf breakage induced by downwash flow. Maximizing the utilization of downwash flow while avoiding lateral air movement outside the intended target crop area is a major issue for chemical application with UAV sprayers, particularly in light of the increasingly apparent consensus on the need for enhanced environmental protection during the chemical application process. It must be considered that the operation strategy in different scenarios and for different crop targets is not the same, unique requirements should be given on nozzle atomization, flight parameters, adjuvants and aircraft types in specific working situations. In future, the implementation of spray drift prediction, technical procedures development, and other solutions aimed at reducing pesticide drift and improving deposition quality, is expected to promote the adoption of UAV sprayers by more farmers. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Unmanned aerial spraying systems (UASS), i.e., unmanned aerial vehicles designed for pesticide applications, are widely used in East Asia and increasingly prevalent in other regions of the world, including North America and Europe. However, according to a recent report of the Organization for Economic Co-operation and Development, spray drift and exposure caused by these systems are not yet fully understood. In particular, there are at present no peer-reviewed reports on direct exposure of residents and bystanders to spray drift following UASS applications. This lack of data results in regulatory concerns with respect to the environment and human safety. The objective of this study was to quantify environmental, resident and bystander exposure following the application of a plant protection product to an orchard using a commercial UASS under field conditions. Using a fluorescent tracer, horizontal and vertical downwind drift data were collected and direct exposure of residents and bystanders located downwind the sprayed area to spray drift was quantified using display mannequins equipped with personal air sampling pumps. Spray drift and exposure inversely correlated with sampling height and downwind distance. Furthermore, drift and exposure were strongly influenced by wind speed and direction, albeit hardly affected by the growth stage of the trees. In addition, substantially less tracer was extracted from the filters of the air sampling pumps than from the coveralls worn by mannequins, suggesting that direct resident/bystander exposure to spray drift may predominantly occur via the dermal route. This report provides essential data on UASS spray drift potential that are relevant for environmental and health risk assessments related to these systems. The results are compared to predicted values of current regulatory models and previously reported field data on drift and exposure caused by different spraying equipment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Following agricultural application, pesticides can enter streams through runoff during rain events. However, little information is available on the temporal dynamics of pesticide toxicity during the main application period. We investigated pesticide application and large scale in-stream monitoring data from 101 agricultural catchments obtained from a Germany-wide monitoring from April to July in 2018 and 2019. We analysed temporal patterns of pesticide application, in-stream toxicity and exceedances of regulatory acceptable concentrations (RAC) for over 70 pesticides. On a monthly scale from April to July, toxicity to invertebrates and algae/aquatic plants (algae) obtained with event-driven samples (EDS) was highest in May/June. The peak of toxicity towards invertebrates and algae coincided with the peaks of insecticide and herbicide application. Future monitoring, i.e. related to the Water Framework Directive, could be limited to time periods of highest pesticide applications on a seasonal scale. On a daily scale, toxicity to invertebrates from EDS exceeded those of grab samples collected within one day after rainfall by a factor of 3.7. Within two to three days, toxicity in grab samples declined compared to EDS by a factor of ten for invertebrates, and a factor of 1.6 for algae. Thus, toxicity to invertebrates declined rapidly within 1 day after a rainfall event, whereas toxicity to algae remained elevated for up to 4 days. For six pesticides, RAC exceedances could only be detected in EDS. The exceedances of RACs coincided with the peaks in pesticide application. Based on EDS, we estimated that pesticide exposure would need a 37-fold reduction of all analysed pesticides, to meet the German environmental target to keep RAC exceedances below 1 % of EDS. Overall, our study shows a high temporal variability of exposure on a monthly but also daily scale to individual pesticides that can be linked to their period of application and related rain events., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Pesticide residues on plant surfaces are a primary source of pesticide bioaccumulation in crops. In this context, we propose a mechanism-based model for understanding the pesticide fate on the plant surface following aerial application, taking into account fate modelling of the pesticide spray solution on the plant surface. Using chlorothalonil as an example, the simulation results revealed that the spray solution dissipated rapidly after aerial application, resulting in the formation of a saturated pesticide solution, which facilitated the diffusion process of the pesticide residue from the plant surface into the peel tissue. The proposed model generated higher simulated residue concentrations in the peel or pulp than the current model, owing to the proposed model's assumption of rapid dissipation of the spray solution. This indicated that the proposed model specified the influence of the spray solution on the plant's exposure to residues via the surface deposition pathway, whereas the current modelling approach presented a generic estimate of the residue dissipation on the plant surface that linked to the residue's fate in the soil.

Background: Integrating unmanned aerial vehicles (UAV) as a new method of pesticide application into existing commercial crop protection systems requires extensive research and comparison to conventional, proven application technology. Pest control expressed as efficacy against target pests, and spray quality expressed as coverage and chemical residue are three key criteria. We investigated and compared these quantitative parameters between a multi-rotor UAV and conventional piloted airplanes in two commercial alfalfa production systems., Results: Effective and equivalent control of leaf-feeding insect pests was achieved by both methods of aerial application when delivering chlorantraniliprole at the same labeled use rate in different spray volumes (46.8 and 93.5 L ha -1 ) on commercially grown alfalfa in California. Residue levels and spray coverage were also comparable and consistent between the UAV and airplane applications across three sampling techniques, specifically residue levels on alfalfa, insecticide recovery from filter paper, and spray coverage on water sensitive cards. Differences in droplet size and deposit characteristics were more variable for the UAV than airplanes based on analysis of deposition images., Conclusion: The results of this study provide confidence supporting the use of small-scale multi-rotor UAVs for pesticide application on agricultural crops. According to the parameters tested, UAV application quality and crop protection performance were comparable to that of the conventional fixed wing airplane application. However, the droplet spectrum and the short-term fate of droplets from unmanned aerial spray system require further optimization for effective and efficient crop protection with minimal risk to the environment., (© 2021 Society of Chemical Industry.)

Canopy characterisation is a key factor for the success and efficiency of the pesticide application process in vineyards. Canopy measurements to determine the optimal volume rate are currently conducted manually, which is time-consuming and limits the adoption of precise methods for volume rate selection. Therefore, automated methods for canopy characterisation must be established using a rapid and reliable technology capable of providing precise information about crop structure. This research providedregression models for obtaining canopy characteristics of vineyards from unmanned aerial vehicle (UAV) and satellite images collected in three significant growth stages. Between 2018 and 2019, a total of 1400 vines were characterised manually and remotely using a UAV and a satellite-based technology. The information collected from the sampled vines was analysed by two different procedures. First, a linear relationship between the manual and remote sensing data was investigated considering every single vine as a data point. Second, the vines were clustered based on three vigour levels in the parcel, and regression models were fitted to the average values of the ground-based and remote sensing-estimated canopy parameters. Remote sensing could detect the changes in canopy characteristics associated with vegetation growth. The combination of normalised differential vegetation index (NDVI) and projected area extracted from the UAV images is correlated with the tree row volume (TRV) when raw point data were used. This relationship was improved and extended to canopy height, width, leaf wall area, and TRV when the data were clustered. Similarly, satellite-based NDVI yielded moderate coefficients of determination for canopy width with raw point data, and for canopy width, height, and TRV when the vines were clustered according to the vigour. The proposed approach should facilitate the estimation of canopy characteristics in each area of a field using a cost-effective, simple, and reliable technology, allowing variable rate application in vineyards.

Background: Unmanned Aerial Vehicles (UAVs), a new method of application to deliver pesticides, is rapidly being adopted for commercial use in crop protection in East Asia with increasing worldwide interest. Pest control in mature almond orchards with dense foliar canopies presents greater coverage challenges than field crops and smaller orchard or vineyard crops. We investigated the use of an electric hexacopter to provide acceptable spray deposition and canopy penetration to be considered credible for use in an almond pest control program., Results: The performance of the aerial and ground methods at different spray volumes were compared by analyzing spray deposition on water sensitive papers, insecticide residues on filter papers and residues on whole unhulled almonds at three canopy elevations. Overall residue levels of chlorantraniliprole insecticide on whole unhulled almonds across all pooled canopy strata were similar between UAV applied at 46.8 L/ha and 93.5 L/ha and the comparative air blast sprayer treatments applied at 935 L/ha. However, significant interactions between canopy elevation and spray method showed distinct residue patterns between the two application methods. Penetration and spray deposition at the lower canopy were observed and validated for the UAV application. Pest efficacy was evaluated by measuring nut damage at harvest., Conclusion: This study presents promising data that support the potential innovative integration of UAV's into crop protection programs for large canopy crops such as almonds and may guide future research for developing relevant label recommendations., (© 2020 Society of Chemical Industry.)

Background: The efficacy and environmental sustainability of pesticide application largely depend on maximizing target coverage, while minimizing off-target losses. Recently, laboratory-based measurements were used to develop new cannon-type spout to increase the droplet size spectra produced by a pneumatic vineyard sprayer. The study described below evaluated the effectiveness of the new device to reduce off-target losses (both in-field and off-field ground losses), and to distribute an adequate canopy spray. Field trials were conducted to measure canopy spray deposition, canopy coverage, and off-target losses from a multiple-row pneumatic sprayer equipped with newly-designed spout under three different positional configurations. The configurations were defined by the variation of liquid release positions from the inner to the outer part of the cannon-type spout: conventional, alternative, and extreme. Each configuration was tested in a vineyard by applying a solution of water and yellow-dye tracer., Results: It was confirmed that the increased droplet size corresponding to the alternative and extreme liquid release positions has no effect on total canopy deposition or coverage. The alternative and extreme configurations produced reduced off-field losses, up to 75% and 83%, respectively, by increasing the droplet size spectra. These reduced off-field losses imply increased in-field losses of 13% and 16%, respectively., Conclusions: The newly-designed pneumatic spout offers the first effective option for environmentally-friendly pneumatic spray pesticide application with the guarantee of canopy spray deposition and coverage levels similar to those obtained with conventional pneumatic application. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Precise timing of pesticide applications, as recommended by decision-support systems, can ensure crop protection, while maintaining efficient use of pesticides, yet farmers often deviate from recommended timing strategies. Here, we assess and explain farmers' choices to follow or not follow recommendations for the timing of fungicide applications against potato late blight in Switzerland., Result: Based on daily fungicide application records as well as regional application recommendations and disease pressure, we found that 36% of applications took place earlier than recommended. Using regression analysis, we identified the exposure to economic risks of infection, susceptibility of the planted potato varieties to late blight infections, as well as yearly differences in disease occurrence as the most important determinants of farmers' application decision., Conclusion: Our results indicate that decisions to not follow application recommendations and apply early are linked to available information and uncertainty with respect to disease predictions. Based on our results, we make recommendations on how to account for farmers' uncertainty with regard to the timing of pesticide applications in the design of pesticide policies and agricultural decision-support systems. These include the use of new technologies and data, mandatory reporting and tailor-made taxes and insurance solutions. Although the focus of this article is on late blight in Switzerland, our analysis can easily be extended to other countries and important plant diseases like powdery mildew in grapevines or Fusarium head blight in winter wheat. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Unmanned aerial vehicles (UAVs) have been used in agriculture to collect imagery for crop and pest monitoring, and for decision-making purposes. Spraying-capable UAVs are now commercially available worldwide for agricultural applications. Combining UAV weed mapping and UAV sprayers into an UAV integrated system (UAV-IS) can offer a new alternative to implement site-specific pest management., Results: The UAV-IS was 0.3- to 3-fold more efficient at identifying and treating target weedy areas, while minimizing treatment on non-weedy areas, than ground-based broadcast applications. The UAV-IS treated 20-60% less area than ground-based broadcast applications, but also missed up to 26% of the target weedy area, while broadcast applications covered almost the entire experimental area and only missed 2-3% of the target weeds. The efficiency of UAV-IS management practices increased as weed spatial aggregation increased (patchiness)., Conclusion: Integrating UAV imagery for pest mapping and UAV sprayers can provide a new strategy for integrated pest management programs to improve efficiency and efficacy while reducing the amount of pesticide being applied. The UAV-IS has the potential to improve the detection and control of weed escapes to reduce/delay herbicide resistance evolution. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

This study developed a procedure to select a set of 5-y meteorological data with the potential to estimate the highest concentrations ("worst-case scenario") in air dispersion modeling of pesticide applications with American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD). The study analyzed the relationship between the 95 th percentile maximum concentrations estimated by AERMOD and the percentages of low wind speed (LWS, 0.5-2 m/s) in the meteorological data used for the modeling. Statistical analysis showed that they were positively correlated within various distances to different types of emission sources. In addition, the LWS percentages of 1-y data could be used to predict the LWS percentages of 5-y data for the same station. Based on these results, the selection procedure for meteorological data began with the evaluation of 1-y data quality and LWS percentages for all the available stations in California, USA, counties with high use of a pesticide of interest. Five-year meteorological data were then processed for the top 5 stations with the highest LWS percentages to perform AERMOD modeling. Finally, the air concentration estimates of the modeled meteorological data were compared to determine the worst-case scenario data. This procedure provided a strategic plan for selecting meteorological data for AERMOD modeling of pesticide applications in California. The procedure was applied to the modeling of residential structural fumigations and determined that the 5-y (2011-2015) data of the weather station WBAN 93134 (downtown Los Angeles, University of Southern California campus) was the worst-case scenario meteorological data for this modeling case. Integr Environ Assess Manag 2019;15:648-658. Published 2019. This article is a U.S. Government work and is in the public domain in the USA., (Published 2019. This article is a U.S. Government work and is in the public domain in the USA.)

Solid set canopy delivery systems (SSCDS) are a novel foliar agrochemical delivery system designed as an alternative for airblast sprayers in high density fruit production. This study tested the pest management potential, coverage, and chemical deposition of an SSCDS using commercially available microsprinkler components over the course of a growing season. Spray coverage and deposition for a representative airblast sprayer and SSCDS were evaluated using water sensitive paper and tartrazine dye, respectively. Foliar sprays for pest suppression were applied through both systems, and damage assessments were taken at the midpoint and end of the growing season. SSCDS sprays demonstrated similar levels of coverage on the adaxial leaf surface as airblast sprays, but significantly lower coverage on the abaxial surface. However, mean levels of foliar chemical deposition was generally higher in the SSCDS. Evaluations found minimal arthropod and fungal damage in both airblast and SSCDS treated plots compared to untreated trees. The SSCDS was shown to be a viable alternative to the airblast, with inherent advantages such as rapid application time and improved worker safety. Furthermore, higher deposition on SSCDS treated foliage supports the hypothesis that SSCDS provide a higher droplet capture rate in the canopy, with less off-target loss and drift than airblast sprayers.

The plant microbiome is known to be influenced by certain biotic as well as abiotic factors. Nevertheless, the drivers for specific changes in microbial community composition and structure are largely unknown. In the present study, the effects of chemical and biological treatments for plant protection on the indigenous microbiome of Camellia sinensis (L.) Kuntze were contrasted. Assessment of bacteria-specific ribosomal RNA gene fragment amplicons from a representative set of samples showed an increased microbial diversity in treated plants when compared to untreated samples. Moreover, distinct microbial fingerprints were found for plants subjected to a conventional pesticide treatment with lime sulfur as well as for plants that were biologically treated with a Piriformospora indica spore solution. The bacterial community of pesticide-treated plants was augmented by 11 taxa assigned to Proteobacteria and Actinobacteria. In contrast, plants from biological control treatments were augmented by 10 taxa representing a more diversified community enrichment and included members of Actionobacteria, Proteobacteria, Bacteroidetes, Planctomycetes, and Verrucomicrobia. Complementary, molecular quantification of fungi in the samples showed a significantly lower number of internal transcribed spacer copies in plants subjected to biological control treatments, indicating the highest efficiency against fungal pathogens. The overall results show that leaves that are used for tea production show distinct microbiome shifts that are elicited by common pest and pathogen management practices. These shifts in the microbial population indicate non-target effects of the applied treatments., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In Washington State, half of all pesticide-related illnesses in agriculture result from drift, the off-target movement of pesticides. Of these, a significant proportion involve workers on another farm and orchard airblast applications. We compared the spray drift exposure reduction potential of two modern tower sprayers - directed air tower (DAT) and multi-headed fan tower (MFT), in relation to a traditional axial fan airblast (AFA) sprayer. We employed real-time particle monitors (Dylos DC1100) during a randomized control trial of orchard spray applications. Sections of a field were randomly sprayed by three alternating spray technologies - AFA, DAT and MFT - while monitors sampled particulate matter above and below the canopy at various downwind locations in a neighboring field. Geometric mean particle mass concentrations (PMC) outside the intended spray area were elevated during all applications at all of our sampling distances (16-74 m, 51-244 ft). After adjusting for wind speed and sampling height, the 75th percentile (95% confidence interval) PMC level was significantly greater during spray events than background levels by 105 (93, 120) μg/m 3 , 49 (45, 54) μg/m 3 and 26 (22, 31) μg/m 3 during AFA, DAT and MFT applications, respectively. Adjusted PMC levels were significantly different between all three sprayers. In this study, tower sprayers significantly reduced spray drift exposures in a neighboring orchard field when compared to the AFA sprayer, with the MFT sprayer producing the least drift; however these tower sprayers did do not fully eliminate drift., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: The efficacy of treatments in vineyards largely depends on the necessary balance between leaf coverage and spray drift and, therefore, knowledge about droplet size is of major importance, but scarce scientific information is available on pneumatic spraying, often adopted in this crop. The objective of this work was to obtain the relationships between the droplet size spectra characterization parameters and the main affecting factors in pneumatic nozzles., Results: Three liquid flow rates (LFR) and four air speeds (AS) were combined in laboratory conditions to assess their influence on the droplet size spectra (D10, D50 and D90), homogeneity (Relative Span Factor, RSF) and driftability (V 100 ) in two different air shear nozzles (cannon-type and hand-type nozzles). The droplet size parameters were significantly affected by LFR and AS, and a model was fitted to predict droplet size in every spout type. The droplet V 100 was also affected by both factors. The RSF was similar in both cases but did not follow regular trends., Conclusions: The findings obtained can help vineyard farmers and technicians to effectively increase the efficiency and, therefore, the efficacy of the pesticide treatments reducing at the same time the spray drift risk by selecting appropriately the optimal values of the main operational parameters: LFR and AS. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Pesticides, despite their known toxicity, are widely used in developing countries for agricultural purposes., Objectives: To find various patterns of hardware use for spraying of insecticides, prevalent storage practice adopted by the user, types of personal protective equipments used for the handling of chemicals; to detect dangerous practices and the extent to which safety norms being followed by the users during the application/treatments, and finally their knowledge concerning the risks of pesticides., Materials and Methods: The agriculture workers who had been involved in pesticide application for agricultural purpose were interviewed face-to-face to gain information on the following determinants of pesticide exposure: Types, treatment equipment, use of personal protection and safety measures during the application/treatments and knowledge of the risks of pesticide exposure., Results: Hundred workers, aged between 21 and 60 years old, were included. Pesticides were mostly applied with manual equipment using Knapsack (70%) and only 5% farmers were using Tractor-mounted sprayer. Workers frequently performed tasks involving additional exposure to pesticides (mixing chemicals, 66%, or washing equipment, 65%). Majority of the workers/applicators used no personal protection measures or used it defectively/partially. Most of the workers/respondents (77%) did not bother for safety and health risks of pesticide exposure., Conclusions: Workers involved in pesticide application use personal protection measures very poorly and defectively. Almost half of the applicators were not following right direction with respect to wind direction while spraying, thus it increase the risk of exposure. There is a clear need to develop specific training and prevention programs for these workers. The determinants of pesticide exposure in agricultural workers described in this study should be properly assessed in epidemiological studies of the health effects of pesticides on agricultural workers at national level.