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Introduction: Spread effect is one of the aspects on deposition quality evaluation of pesticide droplets. It could be affected by many factors such as the microstructure of the target plant leaf surface, physical features of the droplets, and the concentration of spray additives. Methods: In this study, using a high-speed photography system, 2.3% glyphosate ammonium salt solution with different concentration of the additive was applied to investigate the impact process of single droplet deposition on the plant leaf surface with burrs. Effect of droplet sizes and velocities on spreading area and dynamic deposition procedure was analyzed using image processing programs. Results: The diffusion factor in the process of droplet spreading was changed over time. The occurrence of bubbles in the droplets was observed in the results. With the bubble generation, the droplet diameter expands and a better diffusion effect is obtained. As a result, better spreading effect was obtained as the droplet diameter was expanded with the generation of bubbles. The significant effects of each physical property of droplets on droplet spreading and the interaction effects between the influencing factors were analyzed. A significant correlation was found between additive concentration, droplet impact velocity, droplet diameters and droplet spreading area. All interactions of concentration:velocity, concentration: diameter, velocity:diameter, and concentration:velocity:diameter had a significant effect on the spreading area of droplets. The study of the factors influencing the process of pesticide droplet impact on the leaf surface contributes to the efficient use of pesticides. Thus, the consumption of pesticides and the resulting impact on the environment can be reduced. [ABSTRACT FROM AUTHOR]

The stickiness of the plant protection products, means their ability to sustain washing out from sprayed plant surfaces from rain, is one of the most critical and important attributes, especially for protective action non-systemic pesticides. Lack or insufficient stickiness will cause a greatly dropping in effectiveness, especially during rainy weather (seasons), which on the other side, will prove favourable conditions for spreading pests on plants. Therefore, selecting plant protection products with good rain retention ability is critical for achieving a satisfactory level of effectiveness in the case of treatments in such weather conditions. This of course, invokes the need to evaluate of this property, which is the object of the given research. Plant protection products were tested alone and in combinations with sticky and wetness agents for evaluation their stickiness ability. The results shows that stickiness ability can vary greatly for different plant protection products, but addition of sticky agent to the pesticide solution can improve it significantly in most of the cases. Hoverer there was some exceptions. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In plant protection, the increasing maturity of unmanned aerial vehicle (UAV) technology has greatly increased efficiency. UAVs can adapt to multiple terrains and do not require specific take-off platforms. They do well, especially in farmland areas with rugged terrain. However, due to the complex flow field at the bottom of a UAV, some of the droplets will not reach the surface of a plant, which causes pesticide waste and environmental pollution. Droplet deposition is a good indicator of the utilization rate of pesticides; therefore, this review describes recent studies on droplet deposition for further method improvement. First, this review introduces the flight altitude, speed, and environmental factors that affect pesticide utilization efficiency and then summarizes methods to improve pesticide utilization efficiency from three aspects: nozzles, electrostatic sprays, and variable spray systems. We also point out the possible direction of algorithm development for a UAV's precision spray. [ABSTRACT FROM AUTHOR]

Stingless bees (Apidae: Meliponini) provide pollination services to crops and produce high–quality honey. The application of agrochemicals during the management of crop pests is an increasing threat to pollinators and the ecosystem services they provide. Biopesticides are considered as better alternatives; however, there is limited evidence of their impact on stingless bees. We evaluated the effect of the most widely used African fungal biopesticide (Metarhizium anisopliae ICIPE 69) on mortality, foraging behavior and pollination success of the African stingless bee Meliponula ferruginea under semi-field conditions. Colonies of M. ferruginea were introduced into four 24 m2 greenhouse compartments containing blooming cucumber (Cucumis sativus) plants. Cucumber plants were sprayed with a suspension of the biopesticide alongside a sterile 0.05% Triton–100–X (control). The experiment was repeated three times during different cucumber growing seasons. Biopesticide application did not significantly affect M. ferruginea mortality, flight activity, flower visitation, pollen foraging, C. sativus fruit set or C. sativus yield. Forager bees acquired a high number of conidia (7,600 ± 54 conidia /bee) immediately after biopesticide application; however, a significant decline was observed in the subsequent days. Conidial persistence and viability on plant surfaces declined significantly with days. There was no correlation between conidial acquisition and pollen load by forager bees (657 ± 29 pollen/bee). This study demonstrates that M. anisopliae ICIPE 69 did not negatively impact M. ferruginea mortality, pollination behaviour and success, and can therefore be safely used in stingless bee–dependent crop systems. [ABSTRACT FROM AUTHOR]

BACKGROUND: Unmanned aerial vehicles (UAVs) are widely used to improve the efficiency of pesticide applications. Low‐volume spraying operations require more efficient deposition of droplets on the target surface. Therefore, pesticide deposition and retention on plant surfaces is a serious challenge for modern precision agriculture. Tank‐mix adjuvants have been used to improve spray dilutions performance; however, their effects on the physicochemical properties of spray dilutions, dosage delivery, and pesticide dosage are unclear. RESULTS: Tank‐mix adjuvant 8860 significantly improved the physicochemical properties of spray dilutions, inhibited spray droplets rebound, improved the wetting and spreading performance of spray dilutions on wheat leaves, and increased the effective deposition of tebuconazole on wheat leaves. Even when its dosage was reduced by one‐third, the spray solution still showed excellent disease control and effective deposition of the active ingredient on wheat leaves. CONCLUSION: The use of appropriate tank‐mix adjuvants in UAV‐based plant protection for wheat can significantly improve the performance of spray dilutions, increase the efficiency of pesticide dosage delivery, and improve disease control. These adjuvants can also help reduce the pesticide use while ensuring their effectiveness. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Pesticide overuse is a major global problem and the cause of this problem is noticeable pesticide loss from undesired bouncing of sprayed pesticide droplets and rain erosion. This further becomes a primary source of soil and groundwater pollution. Herein, the authors report a method that can enhance pesticide droplet deposition and adhesion on superhydrophobic plant leave surfaces by amyloid‐like aggregation of bovine serum albumin (BSA). Through the reduction of the disulfide bond of BSA by tris(2‐carboxyethyl) phosphine hydrochloride (TCEP), the amyloid‐like phase transition of BSA is triggered that rapidly affords abundant phase‐transitioned BSA (PTB) oligomers to facilitate the invasion of the PTB droplet into the nanostructures on a leaf surface. Such easy penetration is further followed by a robust amyloid‐mediated interfacial adhesion of PTB on leaf surface. As a result, after mixing with pesticides, the PTB system exhibits a remarkable pesticide adhesion capacity that is more than 10 times higher than conventional fixation of commercial pesticides. The practical farmland experiments show that the use of PTB aggregation could reduce the use of pesticides by 70–90% while ensuring yield. This work demonstrates that current pesticide dosage in actual agriculture production may be largely reduced by utilizing eco‐friendly amyloid‐like protein aggregation. [ABSTRACT FROM AUTHOR]

[Objectives]This article aimed to reveal the stability of dsRNA in paddy field environment and provide a theoretical basis for efficient application and safety assessment of dsRNA pesticides. [Methods]The green fluorescent protein gene EGFP was used as a template to synthesize dsRNA. Topical treatment was employed for dsRNA exposure of leaves of rice seedlings, and quantitative dsRNA addition was used to process the paddy field water pretreated in various ways. After that, samples were collected in time course and a simple quantitative detection method for trace dsRNA was used to analyze the residual dynamics of dsRNA on leaf surface, in rice plants, and in paddy field water. [Results]Monitoring tests demonstrated that the half-life of dsRNA topically treated on rice leaves was 16 d in green house. In the treated rice plants, the dsRNA concentration gradually increased following the topical treatment(2 μL, 3 000 pg), and reached a peak value on the 12th day, and then decreased slowly. In the leaf topical treatment experiment, the half-life of the total dsRNA inside and outside rice plant was 27 d. Different parts of treated plants were collected and tested for the inside dsRNA content when absorption reached the peak(12 d after treatment). The concentration in the old leaf was slightly higher, and it was found that there was no significant difference among the treated leaf and root, and the concentration in the new leaf was slightly lower. The concentrations of dsRNA in new leaf, roots and old leaf were 0.60, 1.02 and 1.46 times higher than those in treated leaf, respectively. Monitoring the residual dynamics of dsRNA in paddy field water, it was found that in the separated paddy field water in location the half-life of dsRNA was less than 1 h. In both sampled paddy field water and filtered paddy field water, the half-life of dsRNA was about 15 h. In the further inactivated protein-free paddy field water, dsRNA was very stable, similar to that in RNase-Free deionized water, and there was no obvious decreasing tendency within the 28 d of observation. [Conclusions]These results confirmed that foliar treated dsRNA could be absorbed by rice plants and transported systemically, and the residue on the surface and in the plant could exist for a long time. However, dsRNA disappeared quickly when it entered the paddy field water. The protein factor in the paddy field water was the key factor leading to its rapid disappearance, the sediments also functioned to speed the disappearance, whereas ions and plankton had little direct effect. In summary, we believe that dsRNA application in paddy fields has relatively small risk for environmental contamination. To extend the effective control period of dsRNA pesticides, it is necessary to study the formulation of dsRNA pesticides to promote plant absorption. [ABSTRACT FROM AUTHOR]

The application methods and application efficacy of pesticide are closely related to their uptake and translocation behaviors in the plants. The uptake and translocation behaviors of pesticides on the surface and inside of plants are not only related to the physical and chemical properties of pesticides, but also affected by some factors, such as plants species, growth period, growth conditions and application technologies. The uptake and translocation of pesticides in plants and the influencing factors have important guiding significance for the selection of application technologies and the improvement effective utilization of pesticides. This review summarized the uptake and translocation behaviors of pesticides in the plants, the relationship between conduction modes and application technologies of pesticides, and the factors influencing the uptake and translocation behaviors of pesticides. The measures to improve the uptake and translocation behaviors of pesticides were also proposed, which will provide some theoretical support for the safe and reasonable application of pesticides. [ABSTRACT FROM AUTHOR]

5-aminolevulinic acid (5-ALA) has been fully demonstrated as a biodegradable, without resistance, and pollution-free pesticide. However, the lack of targeting and the poor adhesion result in a low utilization rate, limiting its practical application. Herein, a dew-responsive polymer pro-pesticide Pec-hyd-ALA was successfully synthesized by grafting 5-ALA onto the pectin (PEC) backbone via acid-sensitive acylhydrazone bonds. When the pro-pesticide is exposed to acid dew on plant surfaces at night, 5-ALA is released and subsequently converted to photosensitize (Protoporphyrin IX, PpIX)in plant cells, leading to its accumulation and promoting photodynamic inactivation (PDI). An inverted fluorescence microscope has verified the accumulation of tetrapyrrole in plant cells. In addition, the highly bio-adhesive PEC backbone effectively improved the wetting and retention of 5-ALA on leaves. The pot experiment also demonstrated the system's control effect on barnyard grass. This work provides a promising approach to improving the herbicidal efficacy of 5-ALA. [Display omitted] [ABSTRACT FROM AUTHOR]

The salt-responsiveness of Pickering emulsions has significantly influenced their applications due to the large amount of salt on the surface of plant leaves. The present study provided a maleic anhydride-functionalized cellulose nanocrystal-stabilized high internal phase Pickering emulsion (MACNCs-HIPPEs) that was stable to high-concentration salt and used for pesticide delivery. The stability of MACNCs-HIPPEs was investigated by adjusting the oil-phase volume fraction (φ), the MACNCs concentration, NaCl dosages, and the rheological properties. The high internal phase Pickering emulsion was obtained at φ of 0.8 and MACNCs concentration of 2wt% and showed excellent salt stability (NaCl, 1200 mM) and significant storage stability (60 days). The sustained release of imidacloprid (IMI) from imidacloprid-loaded MACNCs-HIPPEs (IMI@MACNCs-HIPPEs) showed a positive correlation to the temperature (15°C, 25°C, 35°C), indicating clear thermo-responsiveness of the prepared pesticide formulation. The test of spread and retention of IMI@MACNCs-HIPPEs on the leaf surface showed a significant advantage compared with the commercial IMI water dispersible granules (CG). All the advantages mentioned above showed the excellent potential of the MACNCs-HIPPEs in delivering lipophilic pesticides. [ABSTRACT FROM AUTHOR]

The phyllosphere harbours a distinctive microbial community that is influenced by plant species, geological locations, and biotic and abiotic environmental factors. Organophosphates represent a significant category of pesticides that are applied to plant surfaces for pest management. Despite substantial research into phyllosphere microorganisms, little is known about the influence of pesticides on the phyllosphere bacterial ecosystem. In the present study, the effect of chlorpyrifos, monocrotophos, and malathion was studied on the phyllosphere bacterial community of Solanum melongena. The plant-inhabitant bacterial population was explored using culturable and high-throughput 16S rRNA gene amplicon sequencing, with and without pesticide application. A total of 165 genera belonging to 14 phyla were observed in the control and 108 genera belonging to 11 phyla in the treated sample. In total, 28 morphologically distinct bacteria were isolated from the abaxial and adaxial surfaces of leaf, and 4 bacteria were found tolerant to pesticides. An increased abundance of Psychrobacter, Janthinobacterium, Sphingomonas, Flavobacterium, and Pedobacter were observed from the pesticide-treated phyllosphere. Overall pesticide impacted the evenness and diversity of the bacterial communities colonizing the S. melongena phyllosphere. [ABSTRACT FROM AUTHOR]

In pesticide and fertilizer applications, retention of spray droplets after they reach the target surface can be limited by droplets splashing, rebounding, or rolling off of the surface. In this study, a novel approach is presented for quantifying the retention efficiency. This approach enables testing of the influence of polymer additives for enhancing the retention efficiency of both real and model agricultural sprays. The results demonstrate that increasing the extensional rheology of the spray solution can increase the retention efficiency by up to 20% and in some cases achieve a total efficiency greater than 95%. The results are consistent on both synthetic surfaces and plant surfaces and suggest that for a particular polymer and surface, the extensional relaxation time alone is sufficient to predict the retention efficiency. [ABSTRACT FROM AUTHOR]

Vast wastage of pesticides has caused significant environmental pollution and economic loss, which occurs in any step during the entire process of pesticide application. However, the existing strategies for controlling pesticide losses are step specific. Here, a comprehensive strategy to substantively improve pesticide efficiency on the basis of precise designs from beginning to end is developed. A water‐based coacervate with synthesized imine‐based dynamic covalent trimeric surfactants to synergistically control encapsulation, deposition, retention, and release of pesticides on water‐repellent plants is constructed. The coacervate consists of nanosized networks and abundant tightly bonded water, leading to effective encapsulation of hydrophilic/hydrophobic pesticides. Meanwhile, the network‐like microstructure entangles with the micro/nanostructures of superhydrophobic surface, ensuring complete deposition on superhydrophobic plant surface after high‐speed impact and inhibition of wind/rainwater erosion. Moreover, the CO2‐induced degradative surfactant coacervate determines the precise pesticide release. The dynamic coacervate as an innovative pesticide formula provides a prospective way for pesticide application, and is expected to promote productive and sustainable agriculture. [ABSTRACT FROM AUTHOR]

To control agricultural pests using pesticide, it need to deposited on the target interface effectively. The deposition of pesticide droplets on the target plant leaves is a complex dynamic process, which can be affected by the micro structure and component characteristics of the plant leaves. The leaves of plants with hydrophilic villi or amorphous waxy usually have good wettability, and the droplets are not easy to bounce and roll off. However, the surface of most plant leaves is covered with cuticular waxy layer, which has epidermal cell protrusion or unique micro-nano structure. Therefore, those leaves are difficult to be wetted, which will lead to pesticide droplets bouncing and fragmentation after it hits the target plant leaves. Statistic data demonstrated that, on average, 20%-30% of the pesticide droplets were lost due to rebound and left in the ecological environment, which was the key factor affecting the effective utilization rate of pesticides. In this paper, the bouncing behavior of droplets on smooth solid surface, rough interface after artificial modification and leaf surface of target plant has been reviewed. The key factors influencing the bouncing behavior of droplets on solid surface have been summarized, and the research progress on how to control the bouncing behavior of pesticide droplets on the solid surface was summarized, which will provide new ideas and directions for improving the target deposition rate and the pesticide utilization rate. [ABSTRACT FROM AUTHOR]

Nonionic surfactants are used as adjuvants in agri-sprays to stabilise pesticides, but what happens when pesticide-loaded micelles are brought into direct contact with plant leaves? As pesticide solubilisation dehydrates the micellar shell and increases the effective hydrophobicity of the surfactant, we hypothesise that these micelles would uptake plant waxes and alter the amount of pesticide solubilized as a result of the re-equilibrating process. The solubility of the pesticide cyprodinil (CP) and its effect on the shape of hexaethylene glycol monododecyl ether (C 12 E 6) micelles were studied using changes in cloud point, nuclear magnetic resonance (NMR), cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS). Similarly, the solubility of wheat leaf waxes was examined, as was the effect of adding leaf waxes to pre-dissolved cyprodinil in micellar C 12 E 6. Wax solubilisation caused pesticide release and shell hydration, and shortened the length of the cylindrical micelles of the CP loaded C 12 E 6. Temperature increase led to a significant rise in the amount of the dissolved waxes, increased pesticide release, increased micellar length, and caused shrinkage and dehydration of the shell. This study indicates that agrochemical sprays are capable of dissolving leaf waxes, and may trigger pesticide release from surfactant micelles upon contact with plant surfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • APEO altered the in-situ SERS signal intensity of pesticides on apples. • APEO did not affect the pesticide removal efficiency of baking soda. • APEO enhanced the pesticide persistence on apples after long-term exposure. Pesticide active ingredients (AIs) are often applied with adjuvants to facilitate the stability and functionality of AIs in agricultural practice. The objective of this study is to investigate the role of a common non-ionic surfactant, alkylphenol ethoxylate (APEO), on the surface-enhanced Raman spectroscopic (SERS) analysis of pesticides as well as its impact on pesticide persistence on apple surfaces, as a model fresh produce surface. The wetted areas of two AIs (thiabendazole and phosmet) mixed with APEO were determined respectively to correct the unit concentration applied on apple surfaces for a fair comparison. SERS with gold nanoparticle (AuNP) mirror substrates was applied to measure the signal intensity of AIs with and without APEO on apple surfaces after a short-term (45 min) and a long-term (5 days) exposure. The limit of detection (LOD) of thiabendazole and phosmet using this SERS-based method were 0.861 ppm and 2.883 ppm, respectively. The result showed that APEO decreased the SERS signal for non-systemic phosmet, while increased SERS intensity of systemic thiabendazole on apple surfaces after 45 min pesticide exposure. After 5 days, the SERS intensity of thiabendazole with APEO was higher than thiabendazole alone, and there was no significant difference between phosmet with and without APEO. Possible mechanisms were discussed. Furthermore, a 1% sodium bicarbonate (NaHCO 3) washing method was applied to test the impact of APEO on the persistence of the residues on apple surfaces after short-term and long-term exposures. The results indicated that APEO significantly enhanced the persistence of thiabendazole on plant surfaces after a 5-day exposure, while there was no significant impact on phosmet. The information obtained facilitates a better understanding of the impact of the non-ionic surfactant on SERS analysis of pesticide behavior on and in plants and helps further develop the SERS method for studying complex pesticide formulations in plant systems. [ABSTRACT FROM AUTHOR]

Pesticides play an indispensable role in agricultural production; however, conventional pesticides generally suffer from a low foliar deposition rate and poor adhesion, resulting in the actual effective dosage reaching the target pests and diseases being <0.1%. In this study, a sol-gel synthesized from polyethylene glycol as a precursor was added to an emulsifiable concentrate, and the polyhydroxy property of the sol-gel was used as an intermediate to load the pesticide to bind onto the cuticle of crop leaves to enhance its adhesion and penetration on the crop foliage. The results showed that the emulsifiable concentrate after the addition of sol-gel had a more compact structure with a regular hexagonal microstructure, that the contact angle with the leaves was reduced by 5.6–7 at different concentrations, that the adhesion performance of pesticides was increased by 26%, that the residual amount on the leaves within 72 h was significantly increased, and that the larvae of pests died at a faster rate, with a 40% increase in mortality. Therefore, sol-gel has great potential for application in improving pesticide utilization and pest control. [Display omitted] • First application of sol-gel polymers beyond extraction. • More regular microstructure after mixing pesticides with sol-gel polymers. • 26% increase in mevalonate adhesion performance with sol-gel polymers. • Sol-gel polymers increased the insecticidal efficiency of pesticides by 40%. [ABSTRACT FROM AUTHOR]

Background The application of the existing PEARL model was extended to include estimations of the concentration of crop protection products in greenhouse (indoor) air due to volatilisation from the plant surface. The model was modified to include the processes of ventilation of the greenhouse air to the outside atmosphere and transformation in the air. Results A sensitivity analysis of the model was performed by varying selected input parameters on a one-by-one basis and comparing the model outputs with the outputs of the reference scenarios. Conclusion The sensitivity analysis indicates that – in addition to vapour pressure – the model had the highest ratio of variation for the rate ventilation rate and thickness of the boundary layer on the day of application. On the days after application, competing processes, degradation and uptake in the plant, becomes more important. [ABSTRACT FROM AUTHOR]

Nanopesticides formulation has been applied in modern agriculture, but the effective deposition of pesticides on plant surfaces is still a critical challenge. Here, we developed a cap-like mesoporous silica (C-mSiO 2) carrier for pesticide delivery. The C-mSiO 2 carriers with surface amino groups present uniform cap-like shape and have an mean diameter of 300 nm and width of 100 nm. This structure would reduce the rolling and bouncing of carriers on plant leaves, leading to improving the foliage deposition and retention. After loading dinotefuran (DIN), polydopamine (PDA) was used to encapsulate the pesticide (DIN@C-mSiO 2 @PDA). The C-mSiO 2 carriers exhibit high drug loading efficiency (24.7%) and benign biocompatibility on bacteria and seed. Except for pH/NIR response release, the DIN@C-mSiO 2 @PDA exhibited excellent photostability under UV irradiation. Moreover, the insecticidal activity of DIN@C-mSiO 2 @PDA was comparable to that of pure DIN and DIN commercial suspension (CS-DIN). This carrier system has the potential for improving the foliage retention and utilization of pesticides. [Display omitted] • Cap-like mesoporous silica (C-mSiO 2) carrier was successfully prepared for pesticide delivery. • The C-mSiO 2 carrier displayed improving foliage adhesion and wettability. • The C-mSiO 2 @PDA carrier possessed a benign biocompatibility and photothermal effect. • DIN@C-mSiO 2 @PDA displayed pH and NIR light-responsive release behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] • Q-CNFs can enhance deposition and retention of droplets on hydrophobic surface. • Q-CNFs can improve the rain-fastness of pesticides on crop leaves by 80%. • Q-LCNFs could enhance retention rate of photosensitive pesticides by 150%. • Q-CNFs deliver anti-pest effect and therefore enhance the performance of pesticides. • Biomass derived Q-CNFs as agrochemical additives realize a circular bioeconomy. One of the globe environmental issues arising from pesticides loss due to sprayed droplets bouncing and rain washing causes severe soil and groundwater pollution. This issue can be tackled by enhancing the deposition of agrichemical sprays and their retention on plant surfaces, which has been proved extremely challenging. Here, we present an eco-friendly system made of surface-modified nanofibres derived from natural lignocellulosic biomass to improve pesticide utilization efficiency via multiple mechanisms. The addition of soft condensed matter polymer cellulose nanofibres (CNFs) could enhance the deposition of droplets on the hydrophobic surface due to the change of rheological properties of the suspension as observed by a high-speed camera. Cationization of CNFs was further proven to enhance the adhesion between droplets and negatively charged plant leaf surfaces via electrostatic interactions. As a result of the combined above effects, the retention rate of fluorescent markers could reach 80% after the rain washing test. In addition, lignin-containing CNFs were also investigated for their capability to protect photosensitive pesticides, whose retention rate increased by 150% due to the anti-UV property of lignin. Quaternized CNFs also enhanced the anti-pest effect of pesticides. Overall, biodegradable and multifunctional CNFs from lignocellulosic biomass were fabricated via relatively simple surface modification and used as additives to sufficiently improve the utilization of pesticides, realizing a sustainable circular economy concept in the agricultural field. [ABSTRACT FROM AUTHOR]

For pesticides to effectively manage pests, they must first be deposited on the target (typically a plant surface) in a manner in which the active ingredient(s) can be readily taken up by the target organism. A plant architectural model that enables the location of various plant components in 3-D space combined with a particle trajectory model has been used to study the interception of spray droplets by various vegetative elements. Results from the simulation are compared with wind tunnel studies of glyphosate deposition on cotton (Gossypium hirsutumL. var. Sicala), sow thistle (Sonchus oleraceusL.) and wild oats (Avena ludovicianaDurieu). An air induction flat fan nozzle (AI110015 at 500kPa pressure) and an extended range flat fan nozzle (XR11002 at 280kPa pressure) were predicted to have similar glyphosate deposition on cotton and sow thistle plants, whereas the extended range nozzle resulted in higher deposit on wild oats. Spray deposition (µgcm-2) on wild oat plants at the 5-leaf stage was more than double the amount of deposition on sow thistle or wild oat plants at the 2-leaf stage. The model was in good agreement with the experimental data except that it tended to over predict deposition on sow thistle plants. [ABSTRACT FROM AUTHOR]

The article discusses the volatisation and the competing processes computed for a pesticide applied to plants in a wind tunnel system which were stimulated with the computation model. The resulting thickness of air boundary layer, rate of plant penetration and rate of phototransformation were compared with diverse literature data. The study shows that the computer simulation of wind tunnel experiments yields values for the rate coefficients of processes at the plant surface. There were also attempts to estimate the missing parameter values based on continued divergent experimental results.

Post-application pesticide emissions from wetted leaf surfaces and soil may present a significant pathway of exposure to humans in nearby residential communities. In this study, high volume air sampling was performed to measure airborne concentrations of the pesticide methamidophos in a residential community in close proximity to aerial spraying. Sampling occurred before, during and 24 h post-application. To evaluate whether predictive models could reliably estimate residential exposure to methamidophos, an emission factor was used for estimating fluxes of volatilized material over the sprayed area for a 1-day post-application period. These flux estimates were then incorporated into a fugitive dust gaussian dispersion model (FDM) for assessing distribution of mass around the sprayed area. The predictive model output was compared with the field air sampler measurements. In our comparison, 1-day flux estimates from the model were found to be associated to observed field measurement data, with an r2=0.63 the day of the spray and r2=0.67 the day after the spray. The volatilization model however appears to underestimate surface emission flux immediately after the spray and overestimate the emission the next day. [Copyright &y& Elsevier]