This study estimates the risks of agricultural pesticides on non-target organisms and the environment by combining detailed pesticide application data for 2015 with the Danish risk indicator ...Pesticide Load. We quantify and map the pesticide load of 59 pesticides on 28 crops and pastures in the EU. Furthermore, we investigate how recent bans on 14 pesticides in the EU could reduce pesticide use and load. Key findings show that the highest pesticide loads per hectare occur in Cyprus and the Netherlands due to high application rates and a high proportion of vegetable production. Chlorpyrifos caused the highest pesticide load per hectare on more than half of the assessed crops before its ban. The ban of 14 pesticides between 2018 and 2023 potentially reduced pesticide loads by 94%, but unobserved substitution effects could offset pesticide load reductions. Although bans on active substances are justified to control certain endpoint risks, our results highlight the potential weaknesses of bans that merely shift risks. These findings contribute to the ongoing scientific and societal discourse on efficiently mitigating pesticides' impacts on non-target organisms and the environment. However, to improve the evaluation of pesticide use, it is vital to enhance the reporting on detailed pesticide use for individual crop-pesticide combinations.
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•Quantified pesticide-related risks in the EU with the Pesticide Load•The cultivation of vegetables incurs the highest pesticide load per hectare•Ban of pesticides decreased pesticide load substantially•The substitution of banned pesticides could offset reduction of pesticide load
Optimization of photosynthetic performance and protection against abiotic stress are essential to sustain plant growth. Photorespiratory metabolism can help plants to adapt to abiotic stress. The ...beneficial role of photorespiration under abiotic stress is further strengthened by cyclic electron flow (CEF) and alternative oxidase (AOX) pathways. We have attempted to critically assess the literature on the responses of these three phenomena—photorespiration, CEF and AOX, to different stress situations. We emphasize that photorespiration is the key player to protect photosynthesis and upregulates CEF as well as AOX. Then these three processes work in coordination to protect the plants against photoinhibition and maintain an optimal redox state in the cell, while providing ATP for metabolism and protein repair. H
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generated during photorespiratory metabolism seems to be an important signal to upregulate CEF or AOX. Further experiments are necessary to identify the signals originating from CEF or AOX to modulate photorespiration. The mutants deficient in CEF or AOX or both could be useful in this regard. The mutual interactions between CEF and AOX, so as to keep their complementarity, are also to be examined further.
Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test ...their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory) was less compromised than the second phase that leads the animal back to the hive (homing flight). The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection.
Ozone (O3) pollution is harmful to plants and ecosystems. Several chemicals have been evaluated to protect plants against O3 deleterious effects. However, they are not adequately efficient and/or the ...environmental safety of their application is questioned. Hence, new chemicals that provide sufficient protection while being safer for environmental application are needed. This study investigates the response of two O3-sensitive plant species (Phaseolus vulgaris L. cv. Pinto and Nicotiana tabacum L. cv. Bel-W3) leaf-sprayed with deionized water (W, control), ethylenediurea (EDU, 1 mM) or melatonin at lower (1 mM) or higher (3 mM) concentrations (Mel_L and Mel_H, respectively), and then exposed to a square wave of 200 ppb O3, lasting 1 day (5 h day−1) for bean and 2 days (8 h day−1) for tobacco. In both species, the photosynthetic activity of O3-exposed plants was about halved. O3-induced membrane damage was also confirmed by increased malondialdehyde (MDA) byproducts compared to control (W). In EDU- and Mel-treated bean plants, the photosynthetic performance was not influenced by O3, leading to reduction of the incidence and severity of O3 visible injury. In bean plants, Mel_L mitigated the detrimental effect of O3 by boosting antioxidant enzyme activities or osmoprotectants (e.g. abscisic acid, proline, and glutathione transferase). In Mel_L-sprayed tobacco plants, O3 negatively influenced the photosynthetic activity. Conversely, Mel_H ameliorated the O3-induced oxidative stress by preserving the photosynthetic performance, preventing membrane damage, and reducing the visible injuries extent. Although EDU performed better, melatonin protected plants against O3 phytotoxicity, suggesting its potential application as a bio-safer and eco-friendlier phytoprotectant against O3. It is worth noting that the content of melatonin in EDU-treated plants remained unchanged, indicating that the protectant mode of action of EDU is not Mel-related.
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•Tobacco and bean plants treated with exogenous melatonin were subjected to ozone.•Melatonin mitigated the detrimental effect of ozone.•Melatonin preserved photosynthetic performance and reduced visible foliar injury.•Melatonin enhanced compatible solutes production and antioxidant enzyme activities.•An opportunity for safer and eco-friendlier phytoprotection against ozone emerges.
Background
To ensure a high level of public health and environmental protection, authorities that deliver scientific expertise to inform decision-makers and the public at large need to be independent ...from external stakeholders and free of conflicts of interest. This independence requires effective rules for managing links of interest (LoIs) and a high level of transparency, including publication of declarations of interest (DoIs) where appropriate. In the particular case of plant protection products (PPPs) within the European Union, these requirements should apply to all Competent Authorities contributing to the marketing authorization processes.
Methods
A comparative analysis of LoIs management procedures was performed on a selection of ten National Competent Authorities from different member states (NCAs). This analysis was based on (i) the identification of 17 criteria aiming at characterizing good practices for LoIs management; (ii) a survey of ten NCAs, based on an analysis of their institutional websites and their responses to official mail requests.
Results
The comparative analysis showed: (i) a frequent lack of transparency of NCAs regarding their procedures for managing LoIs; (ii) a significant heterogeneity between the NCAs’ LoIs management rules, even though they are in charge of comparable missions regarding the marketing of PPPs; (iii) substantial gaps between the LoIs management procedures adopted by several NCAs and the good practices that are promoted by EFSA.
Current limits on their practices regarding LoIs management might open ways for undue external influences on scientific expertise, and ultimately impact negatively the risk management options adopted by national or European authorities. Limitations of this study and its extension for a more thorough overview of the current LoIs management practices are also discussed.
Conclusions
LoIs management and transparency rules need to be improved across NCAs, given their contribution as (co-)rapporteurs or peer reviews participants to the health and environmental risk assessment steps of the EFSA processes. To this end, a common minimum set of rules should be defined by EFSA; recommendations are proposed, based on the best practices implemented by the investigated NCAs. Such progress would contribute promoting high-quality unbiased scientific expertise and enhance EU citizens’ trust.
Aquatic plants have to adapt to the environments distinct from where land plants grow. A critical aspect of adaptation is the dynamics of sequence repeats, not resolved in older sequencing platforms ...due to incomplete and fragmented genome assemblies from short reads. Therefore, we used PacBio long-read sequencing of the Spirodela polyrhiza genome, reaching a 44-fold increase of contiguity with an N50 (a median of contig lengths) of 831 kb and filling 95.4% of gaps left from the previous version. Reconstruction of repeat regions indicates that sequentially nested long terminal repeat (LTR) retrotranspositions occur early in monocot evolution, featured with both prokaryote-like gene-rich regions and eukaryotic repeat islands. Protein-coding genes are reduced to 18,708 gene models supported by 492,435 high-quality full-length PacBio complementary DNA (cDNA) sequences. Different from land plants, the primitive architecture of Spirodela’s adventitious roots and lack of lateral roots and root hairs are consistent with dispensable functions of nutrient absorption. Disease-resistant genes encoding antimicrobial peptides and dirigent proteins are expanded by tandem duplications. Remarkably, disease-resistant genes are not only amplified, but also highly expressed, consistent with low levels of 24-nucleotide (nt) small interfering RNA (siRNA) that silence the immune system of land plants, thereby protecting Spirodela against a wide spectrum of pathogens and pests. The long-read sequence information not only sheds light on plant evolution and adaptation to the environment, but also facilitates applications in bioenergy and phytoremediation.
Abiotic stresses affect crop plants and cause decreases in plant quality and productivity. Plants can overcome environmental stresses by activating molecular networks, including signal transduction, ...stress perception, metabolite production and expressions of specific stress‐related genes. Recent research suggests that chemical priming is a promising field in crop stress management because plants can be primed by chemical agents to increase their tolerance to various environmental stresses. We present a concept to meet this objective and protect plants through priming of existing defense mechanisms avoiding manipulation of the genome. In addition, recent developments in plant molecular biology include the discovery of genes related to stress tolerance, including functional genes for protecting cells and regulatory genes for regulating stress responses. Therefore, enhancing abiotic stress tolerance using a transgenic approach to transfer these genes into plant genomes has attracted more investigations. Both chemical priming agents and genetic engineering can enhance regulatory and functional genes in plants and increase stress tolerance of plants. This review summarizes the latest findings of chemical priming agents and major achievements in molecular approaches that can potentially enhance the abiotic stress tolerance of plants.
The awareness of plant protection products residues causing problems in water bodies is increasing more and more. A lot of effort is being made by countries in investigating the situation of diffuse ...pesticide pollution. This article illustrates a new methodology developed for the implementation of monitoring plans for plant protection products residues in rivers, lakes and groundwater, at river basin scale, based on an operational workflow which, by integrating different databases, let to evaluate site-specific environmental pressures affecting the definition of the related monitoring networks. It follows that sampling and analytical activities, carried out in the monitoring network nodes, not only are functional to water bodies ecological and chemical quality status assessment but are able to highlight possible compromises of environmental balance in agro-ecosystems, deriving from plant protection products use, through the application of environmental modeling able to bring out evolutive trends. This information would allow the Administrators to take increasingly effective initiatives both in the field of controls and authorizations for particular substances, in the light of the negative effects shown, and in the field of spatial planning, being able to dispose of the necessary knowledge in order to take safeguard measures before a certain evolutionary process of degradation becomes irreversible.
Estimating emissions of chemical pesticides used in agriculture is an essential component in evaluating the potential toxicity-related impacts on humans and ecosystems in various comparative risk and ...impact assessment frameworks, such as life cycle assessment, environmental footprinting, absolute environmental sustainability assessment, chemical substitution, and risk prioritization. Emissions related to drift deposition—usually derived from drift experiments—can reach non-target areas, and vary as a function of crop characteristics and application technique. We derive cumulative drift deposition fractions for a wide range of experimental drift functions for use in comparative and mass-balanced approaches. We clarify that cumulative drift deposition fractions require to integrate the underlying drift functions over the relevant deposition area and to correct for the ratio of deposition area to treated field area to arrive at overall mass deposited per unit mass of applied pesticide. Our results show that for most crops, drift deposition fractions from pesticide application are below 0.03 (i.e. 3% of applied mass), except for grapes and fruit trees, where drift fractions can reach 5% when using canon or air blast sprayers. Notably, aerial applications on soybeans can result in significantly higher drift deposition fractions, ranging from 20% to 60%. Additionally, varying the nozzle position can lead to a factor of five differences in pesticide deposition, and establishing buffer zones can effectively reduce drift deposition. To address remaining limitations in deriving cumulative drift deposition fractions, we discuss possible alternative modelling approaches. Our proposed approach can be implemented in different quantitative and comparative assessment frameworks that require emission estimates of agricultural pesticides, in support of reducing chemical pollution and related impacts on human health and the environment.
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•Comparative impact assessments require cumulative estimates of pesticide emissions.•Drift fraction integrates crop-application method-specific drift curves from experiments.•Validity ranges of drift functions and spray nozzle position need to be considered.•Various drift reduction techniques are considered.•Alternative drift modelling approaches may address prevailing limitations.
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