Toward a Reduced Reliance on Conventional Pesticides in European Agriculture

3D Mass Spectrometry Imaging as a Novel Screening Method for Evaluating Biocontrol Agents

The aim of this study was to evaluate innovative mass spectrometry imaging (MSI) for determining the metabolic potential of selected soil bacteria from the genera Bacillus and Priestia in the presence of the phytopathogen Fusarium. This research marks the first application of direct 3D MSI that to visualize interactions between potential biocontrol agents and plant pathogens on agar medium. The LARAPPI/CI-3D-MSI (Laser-Assisted Remote Atmospheric Pressure Imaging/Chemical Ionization-3D Mass Spectrometry Imaging) setup provided valuable insights into the compounds produced by the tested microorganisms, revealing their spatial distributions and their ability to diffuse into the agar medium. Subsequently, a Pathway Impact Analysis of Metabolites was conducted. Ion images based on ultrahigh resolution mass spectrometry data were obtained, including for potentially bioactive compounds. Statistical analysis of the entire MS data set showed that the metabolites identified for Bacillus licheniformis samples were distinctly separated from the Priestia megaterium samples and could be helpful tools for screening biocontrol strains. The LARAPPI/CI MSI technique offers significant advantages over existing MSI methods. Further research using this technology could help validate the effectiveness of various biopreparations and contribute to enhancing the quality of biological plant protection products available on the market.

Postharvest Chitosan Sprays Reduce Bitter Rot and Blue Mold on Apple Fruit

Chitosan is a natural product that has potential use in agriculture for managing diseases. Chitosan has been shown to effectively suppress storage rots when applied postharvest. Application of chitosan pre- and postharvest has the potential to manage both latent and postharvest rots, but these effects are not well studied. Furthermore, to determine the most effective strategy for using chitosan to manage apple diseases, research on application rates, chitosan molecular weight, phytotoxicity potential, and formulation is needed. The objectives of this study were to (i) identify nonphytotoxic concentrations of chitosan on apple fruit; (ii) evaluate commercial chitosan products for reduction of postharvest disease severity on inoculated fruit; (iii) evaluate the effect of preharvest chitosan applications on suppression of latent infections, postharvest rots, and fruit quality; and (iv) evaluate the effect of preharvest plus postharvest chitosan applications on suppression of Penicillium expansum and Colletotrichum fioriniae on inoculated fruit. Under laboratory conditions, chitosan products applied at higher rates were more effective at reducing disease but tended to cause phytotoxicity. This phytotoxic effect was remediated when the product's pH was adjusted to approximately 5. Tidal Grow products applied at 1.0% (vol/vol) chitosan reduced lesion size caused by P. expansum and C. fioriniae on inoculated apples up to 86% compared with a water treatment. Preharvest applications of chitosan and Serenade ASO reduced bitter rot up to 85% on immature fruit in a research orchard. The results from this research suggest that Tidal Grow adjusted to pH approximately 5 can reduce postharvest diseases of apple fruit.

Insect Resistance to Insecticides: Causes, Mechanisms, and Exploring Potential Solutions

Insecticides play a crucial role as the primary means of controlling agricultural pests, preventing significant damage to crops. However, the misuse of these insecticides has led to the development of resistance in insect pests against major classes of these chemicals. The emergence of resistance poses a serious threat, especially when alternative options for crop protection are limited for farmers. Addressing this challenge and developing new, effective, and sustainable pest management approaches is not merely essential but also critically important. In the absence of alternative solutions, understanding the root causes behind the development of resistance in insects becomes a critical necessity. Without this understanding, the formulation of effective approaches to combat resistance remains elusive. With insecticides playing a vital role in global food security and public health, understanding and mitigating resistance are paramount. Given the growing concern over insect resistance to insecticides, this review addresses a crucial research gap by thoroughly examining the causes, mechanisms, and potential solutions. The review examines factors driving resistance, such as evolutionary pressure and excessive pesticide use, and provides a detailed analysis of mechanisms, including detoxifying enzyme overproduction and target site mutations. Providing an analysis of potential solutions, it discusses integrated pest management, strategic insecticide rotation, and the use of new pest control technologies and biological agents. Emphasizing the urgency of a multifaceted approach, the review provides a concise roadmap for sustainable pest management, guiding future research and applications.

Measurement and modelling of water flows and pesticide leaching under low input cropping systems

One current challenge in sustainable agriculture is to redesign cropping systems to reduce the use and impacts of pesticides, and by doing so protect the environment, in particular groundwater, and human health. As a large range of systems could be explored and a wide number of pesticides used, field experiments cannot be carried out to study the sustainability of each of them. Thus, the objectives of this work were (1) to measure water flows and pesticide leaching in six contrasted low input cropping systems based on sunflower-wheat rotation, oilseed rape-wheat-barley rotation, and maize monoculture, experimented for three years in three different soil and climatic conditions, and (2) to assess and to compare the ability of three pesticide fate models (MACRO, PEARL, PRZM) to simulate the observed water flows and pesticide concentrations. The systems were designed using various crop rotations, including cover crops and intercrops. The models were parameterized with generic parameter estimation routines as done for regulatory risk assessment, and a method was developed to parameterize intercrops, not represented in the models: the use of average crop factors, maximum LAI, crop height and rooting depth of the crops constituting the intercrop allowed acceptable simulations of cumulative water flows, but not their dynamic. Twelve pesticides of 70 applied were quantified in lysimeter samples (e.g. bentazone, glyphosate, S-metolachlor), and their concentrations exceeded 0.1 μg L-1 in several occasions. The performance of the models to reproduce pesticide concentrations was generally poor illustrating the great challenge and the progress needed to simulate accurately pesticide transfers into the soil. The best fits to measured data were attained using "worst-case" pesticide sorption and degradation parameters. Overall, MACRO performed better than PEARL and PRZM. The method developed to parameterize intercrops could be used for risk assessment of groundwater contamination by pesticides in low input cropping systems, but the use of the three models without any calibration is likely to underestimate pesticide leaching in several situations.

Identification, characterization, and sensitivity to phytochemicals of a novel Curvularia species associated with leaf spot disease on Curcuma kwangsiensis

A leaf spot disease affecting Curcuma kwangsiensis (Zingiberaceae) has been observed in Qinzhou City, Guangxi Province. Infected leaves exhibit yellow-brown spots that progressively expand and eventually lead to leaf death. Curvularia isolates were obtained from the diseased leaves with tissue isolation and single spore purification methods. To accurately identify these isolates, we analyzed their morphological characteristics and phylogenetic relationships using combinations of ITS, GAPDH, and EF-1α gene sequences. Phylogenetic analysis showed that the investigated strains formed a distinct clade separate from other recognized Curvularia species. Furthermore, the strains exhibited differences in conidiophore size and conidia shape/size. Based on phylogenetic studies, morphology, and pathogenicity tests, the pathogen was identified as a new species named Curvularia qinzhouensis. Optimal conditions for mycelial growth were observed at 30 °C and pH 8. The sensitivity of the pathogen to various phytochemicals was also examined. Honokiol, thymol, and citral demonstrated effective antifungal effects, with EC50 values of 6.72 ± 1.75, 25.74 ± 4.30, and 54.24 ± 4.69 µg/ml, respectively. The present investigation provides the first report of leaf spot disease on C. kwangsiensis caused by C. qinzhouensis, and valuable insights for the prevention and control of this disease.

Single or Blended Application of Non-Microbial Plant-Based Biostimulants and Trichoderma atroviride as a New Strategy to Enhance Greenhouse Cherry Tomato Performance

The need to increase yield and enhance the sustainability of crop production systems has led to the development and employment of natural products, such as plant biostimulants. In recent years, a number of reports have researched the effects of biostimulants on plant performance; however, few studies have focused on the mutual application of microbial and/or non-microbial biostimulants. This research, conducted in the framework of the SO.MI.PR.O.N regional project, aimed to investigate the single or mutual application of three biostimulants, a tropical plant extract (PE), a vegetal protein hydrolysate (PH), and Trichoderma atroviride, on 'Creativo' F1 cherry tomato plants cultivated during two growing cycles (2022-2023 and 2023-2024). Our results showed that plants treated with the combination Tricho + PE + PH had statistically significant higher fresh shoot biomass (+64.2%, 1647.0 g plant-1), total fruit production (+37.9%, 1902.5 g plant-1), marketable fruit production (+52.9%, 1778.5 g plant-1), and average weight of marketable fruits (+53.1%, 17.0 g) compared to control plants (untreated plants). Furthermore, biostimulant treatments, especially T. atroviride, variably enhanced cherry tomato fruits' qualitative traits, such as firmness, total soluble solids, ascorbic acid, lycopene, and total polyphenols compared to control plants. Overall, the best combinations to increase tomato fruit qualitative features were PE + PH, Tricho + PE, and Tricho + PH. From an economic point of view, the best treatment for achieving the highest net return was PE. This study underlines that biostimulant features (yield, qualitative aspects, and economic profitability) can be supported through the application of specific biostimulant combinations.

Antioxidant cysteine and methionine derivatives show trachea disruption in insects

To prevent the deterioration of the global environment, the reduction of chemical pesticide use and the development of eco-friendly pest control technologies are urgent issues. Our recent study revealed that the production of reactive oxygen species (ROS) by dual oxidase (Duox) plays a pivotal role in stabilizing the tracheal network by intermediating the tyrosine cross-linking of proteins that constitute trachea. Notably, the formation of dityrosine bonds by ROS can be inhibited by the intake of an antioxidant cysteine derivative N-acetyl-L-cysteine (NAC), which can suppress insect respiration. In this study, we screened for the derivatives showing insecticidal activity and tracheal formation inhibition. As a result of investigating the soybean pest bug Riptortus pedestris, cysteine and methionine derivatives showed respiratory formation inhibition and high insecticidal activity. In particular, NAC had a slow-acting insecticidal effect, while L-cysteine methyl ester (L-CME) showed relatively fast-acting insecticidal activity. Furthermore, the insecticidal activity of these derivatives was also detected in Drosophila, mealworms, cockroaches, termites, and plant bugs. Our results suggest that some antioxidant compounds have specific tracheal inhibitory activity in different insect species and they may be used as novel pest control agents upon further characterization.

A comprehensive review of integrated management strategies for damping-off disease in chili

Damping-off disease in chili (Capsicum annum L.) cultivation is a significant global issue, severely affecting seeds, seedlings, and young plants, regardless of the location of cultivation, whether in greenhouses or open fields. Despite chili being a widely popular vegetable used in various cuisines globally, farmers face challenges in meeting the growing demand due to the extensive damage caused by this disease, ranging from 20 to 85%. The shelf life and quality of mature pods are also severely affected. Damping-off disease is mainly caused by soil-borne fungus from the Pythium species, with additional contributions from Phytophthora, Fusarium, and Rhizoctonia species. These pathogens' adaptability to diverse environmental conditions and resistance to synthetic fungicides make controlling damping-off on a commercial scale challenging. However, integrated disease management has shown promising results as a remedial approach. In this review, we discuss the current state of chili diseases, the nature of the pathogens causing damping-off, the epidemiology of the disease, and various control mechanisms. In this review, we broadly discuss the current state of chili diseases, the nature of the pathogens causing damping-off, the epidemiology of the disease, and various control mechanisms. Furthermore, we highlight the importance and efficacy of integrated disease management techniques, along with future prospects in unexplored areas, such as host-pathogen interaction and sustainable disease control measures. The information in this review aims to assist chili growers in understanding the epidemiology and management of damping-off in chili cultivation.

What Explains Hop Growers' Fungicide Use Intensity and Management Costs in Response to Powdery Mildew?

Methods for causal inference from observational data are common in human disease epidemiology and social sciences but are used relatively little in plant pathology. We draw upon an extensive data set of the incidence of hop plants with powdery mildew (caused by Podosphaera macularis) collected from yards in Oregon from 2014 to 2017 and associated metadata on grower cultural practices, cultivar susceptibility to powdery mildew, and pesticide application records to understand variation in and causes of growers' fungicide use and associated costs. An instrumental causal forest model identified growers' spring pruning thoroughness, cultivar susceptibility to two of the dominant pathogenic races of P. macularis, network centrality of yards during May-June and June-July time transitions, and the initial strain of the fungus detected as important variables determining the number of pesticide active constituents applied by growers and the associated costs they incurred in response to powdery mildew. Exposure-response function models fit after covariate weighting indicated that both the number of pesticide active constituents applied and their associated costs scaled linearly with the seasonal mean incidence of plants with powdery mildew. Although the causes of pesticide use intensity are multifaceted, biological and production factors collectively influence the incidence of powdery mildew, which has a direct exposure-response relationship with the number of pesticide active constituents that growers apply and their costs. Our analyses point to several potential strategies for reducing pesticide use and costs for management of powdery mildew on hop. We also highlight the utility of these methods for causal inference in observational studies.

Adoption status of integrated pest management (IPM) practices among vegetable growers of Lamjung district of Nepal

The widespread use of highly toxic pesticides for agricultural purposes has raised concerns about their hazardous impact on both human health and the environment. Integrated pest management (IPM) is a strategy designed to tackle pest problems and reduce pesticide use, with the aim of protecting both human health and the environment. This study was conducted in Besishahar, Sundarbazar, Rainas, and Madhyenepal municipalities of the Lamjung district of Nepal in the year 2023 with a sample of 100 vegetable-growing farmers to assess the adoption of IPM practices in vegetable cultivation. Descriptive and inferential statistics were used to analyze the data, and the logit model was used to identify the factors affecting the adoption of IPM practices in vegetable cultivation among farmers. Respondents were grouped into two categories, adopter and non-adopter, based on the extent of adoption of IPM practices. The findings revealed that only 37 % of the total respondents adopted IPM practices for vegetable cultivation. The easy availability of chemical pesticides and lack of bio-pesticides were the major constraints for the adoption of IPM practices in the study area. The output of the binary logit model indicated that greater participation in training, higher education levels, and increased contact with extension agents significantly influence the adoption of IPM practices in vegetable cultivation. The findings could be used to formulate better policies towards increasing the adoption of sustainable approaches in agriculture and regulation.

Evaluating the Efficacy of Plant Extracts in Managing the Bruchid Beetle, Callosobruchus maculatus (Coleoptera: Bruchidae)

An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC50 and LC90. The toxicity percentages of N. tabacum (LC50 = 0.69%, LC90 = 14.59%), N. rustica (LC50 = 0.98%, LC90 = 22.06%), and A. indica (LC50 = 1.09%, LC90 = 68.52%) were notable in terms of the lower LC50 and LC90 values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents.

Evaluation of antifungal potentials of Albizia kalkora extract as a natural fungicide: In vitro and computational studies

The antifungal bioactivity potential of the organic extract of silk tree (Albizia kalkora) was investigated in the current study. The crude extracts of A. kalkora and methanol, n-hexane, chloroform, and ethyl acetate fractions were prepared. The antifungal activity of obtained fractions of A. kalkora was studied at different concentrations ranging from 0.39-50 µg/mL. Dimethyl sulfoxide (DMSO) was taken as a toxicity control, whereas thiophanate methyl (TM) as a positive control. All the fractions significantly reduced the FOL growth (methanolic: 9.49-94.93 %, n-hexane: 11.12-100 %, chloroform: 20.96-91.41 %, and ethyl acetate: 18.75-96.70 %). The n-hexane fraction showed 6.25 µg/mL MIC as compared to TM with 64 µg/mL MIC. The non-polar (n-hexane) fraction showed maximum antifungal bioactivity against FOL in comparison with chloroform, methanol, and ethyl acetate fractions. GC/MS analysis exhibited that the n-hexane fraction contained hexadecanoic acid, 9,12,15-octadecatrienoic acid, 9,12-octadecadienoic acid, bis(2-ethylhexyl) phthalate, methyl stearate, and [1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. The results of in vitro antifungal inhibition were further reinforced by molecular docking analysis. Five virulence proteins of FOL i.e., pH-responsive PacC transcription factor (PACC), MeaB, TOR; target of rapamycin (FMK1), Signal transducing MAP kinase kinase (STE-STE7), and High Osmolarity Glycerol 1(HOG1) were docked with identified phytocompounds in the n-hexane fraction by GC/MS analysis. MEAB showed maximum binding affinities with zinnimide (-12.03 kcal/mol), HOG1 and FMK1with α-Tocospiro-B (-11.51 kcal/mol) and (-10.55 kcal/mol) respectively, STE-STE7 with docosanoic acid (-11.31 kcal/mol), and PACC with heptadecanoic acid (-9.88 kcal/mol) respectively with strong hydrophobic or hydrophilic interactions with active pocket residues. In conclusion, the n-hexane fraction of the A. kalkora can be used to manage FOL.

Synthetic and Natural Antifungal Substances in Cereal Grain Protection: A Review of Bright and Dark Sides

Molds pose a severe challenge to agriculture because they cause very large crop losses. For this reason, synthetic fungicides have been used for a long time. Without adequate protection against pests and various pathogens, crop losses could be as high as 30-40%. However, concerns mainly about the environmental impact of synthetic antifungals and human health risk have prompted a search for natural alternatives. But do natural remedies only have advantages? This article reviews the current state of knowledge on the use of antifungal substances in agriculture to protect seeds against phytopathogens. The advantages and disadvantages of using both synthetic and natural fungicides to protect cereal grains were discussed, indicating specific examples and mechanisms of action. The possibilities of an integrated control approach, combining cultural, biological, and chemical methods are described, constituting a holistic strategy for sustainable mold management in the grain industry.

Laser weeding: opportunities and challenges for couch grass (Elymus repens (L.) Gould) control

Laser weeding may contribute to less dependency on herbicides and soil tillage. Several research and commercial projects are underway to develop robots equipped with lasers to control weeds. Artificial intelligence can be used to locate and identify weed plants, and mirrors can be used to direct a laser beam towards the target to kill it with heat. Unlike chemical and mechanical weed control, laser weeding only exposes a tiny part of the field for treatment. Laser weeding leaves behind only ashes from the burned plants and does not disturb the soil. Therefore, it is an eco-friendly method to control weed seedlings. However, perennial weeds regrow from the belowground parts after the laser destroys the aerial shoots. Depletion of the belowground parts for resources might be possible if the laser continuously kills new shoots, but it may require many laser treatments. We studied how laser could be used to destroy the widespread and aggressive perennial weed Elymus repens after the rhizomes were cut into fragments. Plants were killed with even small dosages of laser energy and stopped regrowing. Generally, the highest efficacy was achieved when the plants from small rhizomes were treated at the 3-leaf stage.

Low-Cost Plant-Protection Unmanned Ground Vehicle System for Variable Weeding Using Machine Vision

This study presents a machine vision-based variable weeding system for plant- protection unmanned ground vehicles (UGVs) to address the issues of pesticide waste and environmental pollution that are readily caused by traditional spraying agricultural machinery. The system utilizes fuzzy rules to achieve adaptive modification of the Kp, Ki, and Kd adjustment parameters of the PID control algorithm and combines them with an interleaved period PWM controller to reduce the impact of nonlinear variations in water pressure on the performance of the system, and to improve the stability and control accuracy of the system. After testing various image threshold segmentation and image graying algorithms, the normalized super green algorithm (2G-R-B) and the fast iterative threshold segmentation method were adopted as the best combination. This combination effectively distinguished between the vegetation and the background, and thus improved the accuracy of the pixel extraction algorithm for vegetation distribution. The results of orthogonal testing by selected four representative spraying duty cycles-25%, 50%, 75%, and 100%-showed that the pressure variation was less than 0.05 MPa, the average spraying error was less than 2%, and the highest error was less than 5% throughout the test. Finally, the performance of the system was comprehensively evaluated through field trials. The evaluation showed that the system was able to adjust the corresponding spraying volume in real time according to the vegetation distribution under the decision-making based on machine vision algorithms, which proved the low cost and effectiveness of the designed variable weed control system.

Targeted Delivery of Sucrose-Coated Nanocarriers with Chemical Cargoes to the Plant Vasculature Enhances Long-Distance Translocation

Current practices for delivering agrochemicals are inefficient, with only a fraction reaching the intended targets in plants. The surfaces of nanocarriers are functionalized with sucrose, enabling rapid and efficient foliar delivery into the plant phloem, a vascular tissue that transports sugars, signaling molecules, and agrochemicals through the whole plant. The chemical affinity of sucrose molecules to sugar membrane transporters on the phloem cells enhances the uptake of sucrose-coated quantum dots (sucQD) and biocompatible carbon dots with β-cyclodextrin molecular baskets (suc-β-CD) that can carry a wide range of agrochemicals. The QD and CD fluorescence emission properties allowed detection and monitoring of rapid translocation (<40 min) in the vasculature of wheat leaves by confocal and epifluorescence microscopy. The suc-β-CDs more than doubled the delivery of chemical cargoes into the leaf vascular tissue. Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that the fraction of sucQDs loaded into the phloem and transported to roots is over 6.8 times higher than unmodified QDs. The sucrose coating of nanoparticles approach enables unprecedented targeted delivery to roots with ≈70% of phloem-loaded nanoparticles delivered to roots. The use of plant biorecognition molecules mediated delivery provides an efficient approach for guiding nanocarriers containing agrochemicals to the plant vasculature and whole plants.

Bioprospection of Phytotoxic Plant-Derived Eudesmanolides and Guaianolides for the Control of Amaranthus viridis, Echinochloa crus-galli, and Lolium perenne Weeds

The phytotoxicities of a selection of eudesmanolides and guaianolides, including natural products and new derivatives obtained by semisynthesis from plant-isolated sesquiterpene lactones, were evaluated in bioassays against three weeds of concern in agriculture (Amaranthus viridis L., Echinochloa crus-galli L., and Lolium perenne L.). Both eudesmanolides and guaianolides were active against the root and shoot growth of all the species, with the eudesmanolides generally showing improved activities. The IC50 values obtained for the herbicide employed as positive control (on root and shoot growth, respectively, A. viridis: 27.8 and 85.7 μM; E. crus-galli: 167.5 and 288.2 μM; L. perenne: 99.1 and 571.4 μM) were improved in most of the cases. Structure-activity relationships were discussed, finding that hydroxylation of the A-ring and C-13 as well as the position, number, and orientation of the hydroxyl groups and the presence of an unsaturated carbonyl group can significantly influence the level of phytotoxicity. γ-Cyclocostunolide was the most active compound in the series, followed by others such as dehydrozaluzanin C and α-cyclocostunolide (outstanding their IC50 values on A. viridis)─natural products that can therefore be suggested as models for herbicide development if further research indicates effectiveness on a larger scale and environmental safety in ecotoxicological assessments.

Eco-friendly biopesticides derived from CO2-Fixing cyanobacteria

There is currently an escalating global demand for the utilization of plant and natural extracts as pesticides due to their minimal health risks. Cyanobacteria are highly valuable organisms with significant potential in agriculture and are of great interest for the development of agrochemical agents as biopesticides. The flexibility and adaptability of Cyanobacteria to various environmental conditions are facilitated by the presence of specialized enzymes involved in the production of biologically active diverse secondary metabolites, including alkaloids, lipopolysaccharides, non-protein amino acids, non-ribosomal peptides, polyketides, terpenoids, and others. This review focuses on the metabolites synthesized from cyanobacteria that have demonstrated effectiveness as antibacterial, antiviral, antifungal agents, insecticides, herbicides, and more. The potential role of cyanobacteria as an alternative to chemical pesticides for environmental conservation is discussed.

Molecular analysis of broad-spectrum induced resistance in rice by the green leaf volatile Z-3-hexenyl acetate

Green leaf volatiles (GLVs), volatile organic compounds released by plants upon tissue damage, are key signaling molecules in plant immunity. The ability of exogenous GLV application to trigger an induced resistance (IR) phenotype against arthropod pests has been widely reported, but its effectiveness against plant pathogens is less well understood. In this study, we combined mRNA sequencing-based transcriptomics and phytohormone measurements with multispectral imaging-based precision phenotyping to gain insights into the molecular basis of Z-3-hexenyl acetate-induced resistance (Z-3-HAC-IR) in rice. Furthermore, we evaluated the efficacy of Z-3-HAC-IR against a panel of economically significant rice pathogens: Pyricularia oryzae, Rhizoctonia solani, Xanthomonas oryzae pv. oryzae, Cochliobolus miyabeanus, and Meloidogyne graminicola. Our data revealed rapid induction of jasmonate metabolism and systemic induction of plant immune responses upon Z-3-HAC exposure, as well as a transient allocation cost due to accelerated chlorophyll degradation and nutrient remobilization. Z-3-HAC-IR proved effective against all tested pathogens except for C. miyabeanus, including against the (hemi)biotrophs M. graminicola, X. oryzae pv. oryzae, and P. oryzae. The Z-3-HAC-IR phenotype was lost in the jasmonate (JA)-deficient hebiba mutant, which confirms the causal role of JA in Z-3-HAC-IR. Together, our results show that GLV exposure in rice induces broad-spectrum, JA-mediated disease resistance with limited allocation costs, and may thus be a promising alternative crop protection approach.

Review on Pesticide Abiotic Stress over Crop Health and Intervention by Various Biostimulants

Plants are essential for life on earth, and agricultural crops are a primary food source for humans. For the One Health future, crop health is crucial for safe, high-quality agricultural products and the development of future green commodities. However, the overuse of pesticides in modern agriculture raises concerns about their adverse effects on crop resistance and product quality. Recently, biostimulants, including microecological bacteria agents and nanoparticles, have garnered worldwide interest for their ability to sustain plant health and enhance crop resistance. This review analyzed the effects and mechanisms of pesticide stress on crop health. It also investigated the regulation of biostimulants on crop health and the multiomics mechanism, combining research on nanoselenium activating various crop health aspects conducted by the authors' research group. The paper helps readers understand the impact of pesticides on crop health and the positive influence of various biostimulants, especially nanomaterials and small molecules, on crop health.

Distinct Genomic Loci Underlie Quantitative Resistance to Meloidogyne enterolobii Galling and Reproduction in Citrullus amarus

Meloidogyne enterolobii is a virulent species of root-knot nematode that threatens watermelon (Citrullus lanatus) production in the southeastern United States. There are no known sources of root-knot nematode resistance in cultivated C. lanatus. Specific genotypes of a wild watermelon relative, C. amarus, are resistant against M. incognita but the genetics that underly this resistance are still unknown and it is not clear that this same resistance will be effective against M. enterolobii. To identify and characterize new sources of resistance to M. enterolobii, we screened 108 diverse C. amarus lines alongside a susceptible C. lanatus cultivar (Charleston Gray) for resistance against M. enterolobii. Different C. amarus genotypes ranged from resistant to susceptible for the three resistance phenotypes measured; mean percent root system galled ranged from 10 to 73%, mean egg mass counts ranged from 0.3 to 64.5, and mean eggs per gram of root ranged from 326 to 146,160. We used each of these three resistance phenotypes combined with whole-genome resequencing data to conduct a genome-wide association scan that identified significant associations between M. enterolobii resistance and 11 single-nucleotide polymorphisms (SNPs) within the C. amarus genome. Interestingly, SNPs associated with reduced galling and egg masses were located within a single quantitative trait locus (QTL) on chromosome Ca03, while reductions in nematode eggs per gram of root were associated with separate QTL on chromosomes Ca04 and Ca08. The results of this study suggest that multiple genes are involved with M. enterolobii resistance in C. amarus and the SNPs identified will assist with efforts to breed for M. enterolobii resistance in watermelon.

Influence of climate change and pesticide use practices on the ecological risks of pesticides in a protected Mediterranean wetland: A Bayesian network approach

Pollution by agricultural pesticides is one of the most important pressures affecting Mediterranean coastal wetlands. Pesticide risks are expected to be influenced by climate change, which will result in an increase of temperatures and a decrease in annual precipitation. On the other hand, pesticide dosages are expected to change given the increase in pest resistance and the implementation of environmental policies like the European ´Farm-to-Fork` strategy, which aims for a 50 % reduction in pesticide usage by 2030. The influence of climate change and pesticide use practices on the ecological risks of pesticides needs to be evaluated making use of realistic environmental scenarios. This study investigates how different climate change and pesticide use practices affect the ecological risks of pesticides in the Albufera Natural Park (Valencia, Spain), a protected Mediterranean coastal wetland. We performed a probabilistic risk assessment for nine pesticides applied in rice production using three climatic scenarios (for the years 2008, 2050 and 2100), three pesticide dosage regimes (the recommended dose, and 50 % increase and 50 % decrease), and their combinations. The scenarios were used to simulate pesticide exposure concentrations in the water column of the rice paddies using the RICEWQ model. Pesticide effects were characterized using acute and chronic Species Sensitivity Distributions built with toxicity data for aquatic organisms. Risk quotients were calculated as probability distributions making use of Bayesian networks. Our results show that future climate projections will influence exposure concentrations for some of the studied pesticides, yielding higher dissipation and lower exposure in scenarios dominated by an increase of temperatures, and higher exposure peaks in scenarios where heavy precipitation events occur right after pesticide application. Our case study shows that pesticides such as azoxystrobin, difenoconazole and MCPA are posing unacceptable ecological risks for aquatic organisms, and that the implementation of the ´Farm-to-Fork` strategy is crucial to reduce them.

Identification of a New Pathogenic fungi Causing Sorghum Leaf Spot Disease and Its Management Using Natural Product and Microorganisms

Sorghum bicolor is cultivated worldwide. Leaf spot of sorghum, which leads to leaf lesions and yield reduction, is a prevalent and serious disease in Guizhou Province, southwest China. In August 2021, new leaf spot symptoms were observed on sorghum leaves. In this study, traditional methods and modern molecular biology techniques were used to isolate and identify the pathogen. Sorghum inoculated with the isolate GY1021 resulted in reddish brown lesion that similar to symptoms observed in the field: the original isolate inoculated was reisolated and Koch's postulates were fulfilled. Based on morphological features and phylogenetic analysis of the internal transcribed spacer (ITS) combined sequence with β-tubulin (TUB2) and translation elongation factor 1-α (TEF-1α) genes, the isolate was identified as Fusarium thapsinum (Strain accession: GY 1021; GenBank Accession: ITS (ON882046), TEF-1α (OP096445), and β-TUB (OP096446)). Then, we studied the bioactivity of various natural products and microorganisms against F. thapsinum using the dual culture experiment. Carvacrol, 2-allylphenol, honokiol, and cinnamaldehyde showed excellent antifungal activity, with EC₅₀ values of 24.19, 7.18, 46.18, and 52.81 µg/mL, respectively. The bioactivity of six antagonistic bacteria was measured using a dual culture experiment and the mycelial growth rate method. Paenibacillus polymyxa, Bacillus amyloliquefaciens and Bacillus velezensis displayed significant antifungal effects against F. thapsinum. This study provides a theoretical basis for the green control of leaf spot of sorghum.

Inhibition of Botrytis cinerea Growth and Suppression of Gray Mold on Petunia Leaves Using Chitosan

Exogenous application of chitosan has been shown to reduce plant disease severity in food crops; however, less is known about the potential use of chitosan in floriculture. The objective of this study was to investigate the effectiveness of chitosan to suppress gray mold on petunia leaves caused by Botrytis cinerea using in vitro and in planta approaches. We also aimed to determine if chitosan molecular weight influences efficacy. Medium and high molecular weight reagent grade chitosan reduced growth of B. cinerea in vitro at chitosan concentrations ranging from 1.25 to 2% (v/v), while low molecular weight reagent grade chitosan only reduced growth at 2.0% (v/v). In detached leaf assays, all reagent grade chitosan treatments reduced Botrytis lesion size on petunia leaves up to 65% compared to the water control. The commercial product Tidal Grow reduced in vitro growth of Botrytis, starting at 0.5%, and reduced disease severity at 0.75% on petunia leaves. The commercial product ARMOUR-Zen 15 reduced Botrytis growth in vitro at 3.75% and higher and reduced disease severity at 0.3 and 1.0% on petunia leaves. Under greenhouse conditions, low, medium, and high molecular weight reagent grade chitosan and ARMOUR-Zen 15 at 0.4% chitosan reduced Botrytis lesion size on petunia leaves up to 60% compared to the water control. Suppression in vitro suggests that chitosan may have direct phytotoxic effects on fungal growth, however our in planta and greenhouse trials suggest that additional modes of action may also play a role in the observed suppressive effects.

Surfactin and Spo0A-Dependent Antagonism by Bacillus subtilis Strain UD1022 against Medicago sativa Phytopathogens

Plant growth-promoting rhizobacteria (PGPR) such as the root colonizers Bacillus spp. may be ideal alternatives to chemical crop treatments. This work sought to extend the application of the broadly active PGPR UD1022 to Medicago sativa (alfalfa). Alfalfa is susceptible to many phytopathogens resulting in losses of crop yield and nutrient value. UD1022 was cocultured with four alfalfa pathogen strains to test antagonism. We found UD1022 to be directly antagonistic toward Collectotrichum trifolii, Ascochyta medicaginicola (formerly Phoma medicaginis), and Phytophthora medicaginis, and not toward Fusarium oxysporum f. sp. medicaginis. Using mutant UD1022 strains lacking genes in the nonribosomal peptide (NRP) and biofilm pathways, we tested antagonism against A. medicaginicola StC 306-5 and P. medicaginis A2A1. The NRP surfactin may have a role in the antagonism toward the ascomycete StC 306-5. Antagonism toward A2A1 may be influenced by B. subtilis biofilm pathway components. The B. subtilis central regulator of both surfactin and biofilm pathways Spo0A was required for the antagonism of both phytopathogens. The results of this study indicate that the PGPR UD1022 would be a good candidate for further investigations into its antagonistic activities against C. trifolii, A. medicaginicola, and P. medicaginis in plant and field studies.

First Report on Colletotrichum fructicola Causing Anthracnose in Chinese Sorghum and Its Management Using Phytochemicals

Sorghum bicolor is cultivated worldwide. Leaf spots on sorghum, which lead to leaf lesions and impaired growth, are prevalent and severe in Guizhou Province, Southwest China. In August 2021, new leaf spot symptoms were observed on sorghum plants growing in agricultural fields. We used conventional tissue isolation methods and pathogenicity determination tests. Inoculations of sorghum with isolate 022ZW resulted in brown lesions similar to those observed under field conditions. The original inoculated isolates were reisolated and fulfilled Koch's postulates. Based on the morphological character and phylogenetic analyses of the combined sequences of the internal transcribed spacer (ITS) region and the β-tubulin (TUB2) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes, we identified the isolated fungus as C. fructicola. This paper is the first to report this fungus-causing disease in sorghum leaves. We studied the sensitivity of the pathogen to various phytochemicals. The sensitivity of C. fructicola to seven phytochemicals was measured using the mycelial growth rate method. Honokiol, magnolol, thymol, and carvacrol displayed good antifungal effects, with EC₅₀ (concentration for 50% of the maximal effect) values of 21.70 ± 0.81, 24.19 ± 0.49, 31.97 ± 0.51, and 31.04 ± 0.891 µg/mL, respectively. We tested the control effect of the seven phytochemicals on the anthracnose caused by C. fructicola: honokiol and magnolol displayed good field efficacy. In this study, we expand the host range of C. fructicola, providing a basis for controlling sorghum leaf diseases caused by C. fructicola.

Vineyard Management and Physicochemical Parameters of Soil Affect Native Trichoderma Populations, Sources of Biocontrol Agents against Phaeoacremonium minimum

Native strains of Trichoderma in vineyard soil represent an opportunity for reducing the incidence of grapevine trunk diseases (GTDs) in vineyards. Moreover, its relationship with the environment (physicochemical soil characteristics and farming management practices) remains unclear. In the current study, a survey was carried out on farming management used by viticulturists, and soil samples were studied to analyze their physicochemical properties and to isolate Trichoderma strains. Later, statistical analyses were performed to identify possible correlations between Trichoderma populations, soil management and soil characteristics. In addition, in vitro tests, including antibiosis and mycoparasitism, were performed to select those Trichoderma strains able to antagonize Phaeoacremonium minimum. In this study a positive correlation was found between the iron content and pH in the soil, and a lower pH increases Trichoderma populations in soils. Vineyard management also affects Trichoderma populations in the soil, negatively in the case of fertilization and tillage and positively in the case of herbicide spraying. Two Trichoderma native strains were selected as potential biocontrol agents (Trichoderma gamsii T065 and Trichoderma harzianum T087) using antibiosis and mycoparasitism as mechanisms of action. These results led to the conclusion that native Trichoderma strains hold great potential as biological control agents and as producers of secondary metabolites.

Melatonin as a Possible Natural Anti-Viral Compound in Plant Biocontrol

Melatonin is a multifunctional and ubiquitous molecule. In animals, melatonin is a hormone that is involved in a wide range of physiological activities and is also an excellent antioxidant. In plants, it has been considered a master regulator of multiple physiological processes as well as of hormonal homeostasis. Likewise, it is known for its role as a protective biomolecule and activator of tolerance and resistance against biotic and abiotic stress in plants. Since infections by pathogens such as bacteria, fungi and viruses in crops result in large economic losses, interest has been aroused in determining whether melatonin plays a relevant role in plant defense systems against pathogens in general, and against viruses in particular. Currently, several strategies have been applied to combat infection by pathogens, one of them is the use of eco-friendly chemical compounds that induce systemic resistance. Few studies have addressed the use of melatonin as a biocontrol agent for plant diseases caused by viruses. Exogenous melatonin treatments have been used to reduce the incidence of several virus diseases, reducing symptoms, virus titer, and even eradicating the proliferation of viruses such as Tobacco Mosaic Virus, Apple Stem Grooving Virus, Rice Stripe Virus and Alfalfa Mosaic Virus in tomato, apple, rice and eggplant, respectively. The possibilities of using melatonin as a possible natural virus biocontrol agent are discussed.

Efficient polymer-mediated delivery system for thiocyclam: Nanometerization remarkably improves the bioactivity toward green peach aphids

The unscientific application of synthetic pesticides has brought various negative effects on the environment, hindering the sustainable development of agriculture. Nanoparticles can be applied as carriers to improve pesticide delivery, showing great potential in the development of pesticide formulation in recent years. Herein, a star polymer (SPc) was constructed as an efficient pesticide nanocarrier/adjuvant that could spontaneously assemble with thiocyclam or monosultap into a complex, through hydrophobic association and hydrogen bonding, respectively, with the pesticide-loading contents of 42.54% and 19.3%. This complexation reduced the particle sizes of thiocyclam from 543.54 to 52.74 nm for pure thiocyclam, and 3 814.16 to 1 185.89 nm for commercial preparation (cp) of thiocyclam. Interestingly, the introduction of SPc decreased the contact angles of both pure and cp thiocyclam on plant leaves, and increased the plant uptake of cp thiocyclam to 2.4-1.9 times of that without SPc. Meanwhile, the SPc could promote the bioactivity of pure/cp thiocyclam against green peach aphids through leaf dipping method and root application. For leaf dipping method, the 50% lethal concentration decreased from 0.532 to 0.221 g/L after the complexation of pure thiocyclam with SPc, and that decreased from 0.390 to 0.251 g/L for cp thiocyclam. SPc seems a promising adjuvant for nanometerization of both pure and cp insecticides, which is beneficial for improving the delivery efficiency and utilization rate of pesticides.

Nanoencapsulation application to prolong postharvest shelf life

This review offers our opinion on current and future trends regarding nanoencapsulation interventions to extend postharvest shelf life of stored grains, fruits, and vegetables. Herein, we considered two major factors influencing postharvest shelf life for comments: aerobic food spoilage microorganisms and stored pests. Nanoemulsions, edible/active coatings, and nanopackaging loading essential oils as antimicrobial, antioxidant, or pesticide showed promising results in prolonged shelf life at room/cold storage without compromising quality, organoleptic properties, and postharvest physiology. Trends with nanoencapsulation using plant-based pesticides as agrochemical-free methods to keep produce fresh longer were commented as potential candidates for prolonging the shelf life of stored grains and fruits at the postharvest stage. Research with potential large-scale feasibility is intensive, but safety assessment is required and remains little explored.

Identification and utilization of a new Bacillus amyloliquefaciens XY-1 against Fusarium head blight

Fusarium head blight (FHB) is a global wheat grain disease caused by Fusarium graminearum. Biological control of FHB is considered to be an alternative disease management strategy that is environmentally benign, durable, and compatible with other control measures. In this study, to screen antagonistic bacteria with the potential to against FHB, 45 strains were isolated from different tissues of wheat. Among them, seven strains appeared to effectively inhibit F. graminearum growth, the antagonistic bacterium named XY-1 showed a highly antagonistic effect against FHB using dual culture assays. The strain XY-1 was identified as Bacillus amyloliquefaciens by 16S rDNA sequence. Antibiotic tolerance of antagonistic bacteria showed that XY-1 had antagonistic activity against Colletotrichum gloeosporioides, Rhizoctonia solani, Sclerotium rolfsii, and Alternaria alternata. Nutrition tests showed that the most suitable carbon and nitrogen sources were glucose and beef extract, respectively. The optimum growth temperature and pH value were 28 ℃ and 7.4. Antibiotics tolerance cultivation showed that XY-1 had strong resistance to Chloramphenicol and Ampicillin. Wheat spikes inoculation antagonism tests showed that strain XY-1 displayed strong antifungal activity against F. graminearum. Our study laid a theoretical foundation for the application of strain XY-1 as a biological agent in the field to control FHB.

The nexus between biofuels and pesticides in agroforestry: Pathways toward United Nations sustainable development goals

The growth of global population continuously increases the demands for agroforestry-derived products, underpinning a sustainable growth of energy matrix in the sectors of food security, transportation, and industrial is momentous. The high demand for the sustainable energy sources has led to an increase in the application of pesticides associated with growing crops for the production of biofuel. In 2019, the global consumption of pesticides was 4.2 million tonnes. Case studies on life cycle assessment (LCA) of pesticides showed that toxicity is the major severe impact of pesticide usage, contributing to human toxicity (∼70%) and freshwater eco-toxicity (>50%). This alarming situation needs a solution as conventional pesticides pose various negative impacts to human and the environment, rendering the biofuel production process unsustainable. In this review, we focus on the interaction between pesticide use, biofuel production, food security for a sustainable balancing in between government benefits, environmental, and human health, aiming to track the implications and impact to the global efforts towards achieving the UN Sustainable Development Goals (SDGs). Even though, there are strict government regulations and legislations pertaining to pesticide use, and policies devised as guidelines for agroforestry sectors to implement and monitor these measures, the discrepancies still exist in between national and supranational entities. To cater the above issue, many efforts have been made to upscale the biofuel production, for example, the United States, Brazil, China and Indonesia have ventured into biofuels production from non-food-crops based feedstock while other developing nations are rapidly catching up. In this perspective, a sustainable nexus between Biofuels-Pesticides-Agroforestry (BPA) is essential to create a sustainable roadmap toward the UN SDGs, to fulfilling the energy, food, and land security. The contribution of technologies in BPA includes genetic modified crops, integrated pest and weed management with controlled release pesticides, use of nano-biopesticides is being reviewed. As a whole, the concept of biofuel processing complex (BPC) and farmers upskilling, together with the effective implementation of efficient policies and Internet of Things (IoT) would be the key to drive the BPA nexus towards fulfilment of SDGs.

Development of an online pan-European Integrated Pest Management Resource Toolbox

The IPM WORKSIPM Resource Toolbox (Toolbox) has been developed as an interactive, online repository of integrated pest management (IPM) resources. Populated with high priority resources for farmers and their advisors during the project, its structure enables additional resources added over time. The repository is a public interactive website, available to anyone looking to access, understand, and implement IPM. Built on an open-source content management system, the toolbox is designed to require minimal post-production site maintenance and support, while being easily expanded to integrate resources from future initiatives. To ensure an efficient but comprehensive website design, population, maintenance, a survey of target user needs was conducted. Different type of IPM stakeholders, both internal and external to the IPMworks project, ranked the key requirements for the Toolbox, such as practical information about diseases and pests' management and economic thresholds: 343 feedbacks and answers from a survey of 10 questions, carried out across Europe in four languages, provided the key elements and foundation for the IPM Resource Toolbox website development and specification. The Toolbox resources are explained in different languages, with images, divided by topics, with the possibility to find additional details and accessible by smartphone.

Bacteria as Biological Control Agents of Plant Diseases

Biological control is an effective and sustainable alternative or complement to conventional pesticides for fungal and bacterial plant disease management. Some of the most intensively studied biological control agents are bacteria that can use multiple mechanisms implicated in the limitation of plant disease development, and several bacterial-based products have been already registered and marketed as biopesticides. However, efforts are still required to increase the commercially available microbial biopesticides. The inconsistency in the performance of bacterial biocontrol agents in the biological control has limited their extensive use in commercial agriculture. Pathosystem factors and environmental conditions have been shown to be key factors involved in the final levels of disease control achieved by bacteria. Several biotic and abiotic factors can influence the performance of the biocontrol agents, affecting their mechanisms of action or the multitrophic interaction between the plant, the pathogen, and the bacteria. This review shows some relevant examples of known bacterial biocontrol agents, with especial emphasis on research carried out by Spanish groups. In addition, the importance of the screening process and of the key steps in the development of bacterial biocontrol agents is highlighted. Besides, some improvement approaches and future trends are considered.

Concentration-dependent effects of effusol and juncusol from Juncus compressus on seedling development of Arabidopsis thaliana

Juncus species are valuable sources of phenanthrene compounds that have been used in traditional Chinese medicine for thousands of years. Effusol and juncusol are the most investigated compounds reported to have antimicrobial and anticancer effects; however, to date, their effects on higher plants have not been investigated. In this study, we examined the effects of effusol and juncusol on the growth and other biochemical parameters of the dicot model plant Arabidopsis thaliana in a concentration-dependent manner with a focus on polyamine metabolism. Phenanthrene induced toxic effects on plant growth and development, while effusol and juncusol induced higher biomass and maintained antioxidant defence mechanisms associated with reduced polyamine degradation. Taken together, our results suggest that these compounds could be good candidates for new biopesticide or biostimulant plant growth regulators in the future.

Identification of Novel and Safe Fungicidal Molecules against Fusarium oxysporum from Plant Essential Oils: In Vitro and Computational Approaches

Phytopathogenic fungi are serious threats in the agriculture sector especially in fruit and vegetable production. The use of plant essential oil as antifungal agents has been in practice from many years. Plant essential oils (PEOs) of Cuminum cyminum, Trachyspermum ammi, Azadirachta indica, Syzygium aromaticum, Moringa oleifera, Mentha spicata, Eucalyptus grandis, Allium sativum, and Citrus sinensis were tested against Fusarium oxysporum. Three phase trials consist of lab testing (MIC and MFC), field testing (seed treatment and foliar spray), and computer-aided fungicide design (CAFD). Two concentrations (25 and 50 μl/ml) have been used to asses MIC while MFC was assessed at four concentrations (25, 50, 75, and 100 μl/ml). C. sinensis showed the largest inhibition zone (47.5 and 46.3 m2) for both concentrations. The lowest disease incidence and disease severity were recorded in treatments with C. sinensis PEO. Citrus sinensis that qualified in laboratory and field trials was selected for CAFD. The chemical compounds of C. sinensis PEO were docked with polyketide synthase beta-ketoacyl synthase domain of F. oxysporum by AutoDock Vina. The best docked complex was formed by nootkatone with -6.0 kcal/mol binding affinity. Pharmacophore of the top seven C. sinensis PEO compounds was used for merged pharmacophore generation. The best pharmacophore model with 0.8492 score was screened against the CMNP database. Top hit compounds from screening were selected and docked with polyketide synthase beta-ketoacyl synthase domain. Four compounds with the highest binding affinity and hydrogen bonding were selected for confirmation of lead molecule by doing MD simulation. The polyketide synthase-CMNPD24498 showed the highest stability throughout 80 ns run of MD simulation. CMNPD24498 (FW054-1) from Verrucosispora was selected as the lead compound against F. oxysporum.

Management of Post-Harvest Anthracnose: Current Approaches and Future Perspectives

Anthracnose is a severe disease caused by Colletotrichum spp. on several crop species. Fungal infections can occur both in the field and at the post-harvest stage causing severe lesions on fruits and economic losses. Physical treatments and synthetic fungicides have traditionally been the preferred means to control anthracnose adverse effects; however, the urgent need to decrease the use of toxic chemicals led to the investigation of innovative and sustainable protection techniques. Evidence for the efficacy of biological agents and vegetal derivates has been reported; however, their introduction into actual crop protection strategies requires the solutions of several critical issues. Biotechnology-based approaches have also been explored, revealing the opportunity to develop innovative and safe methods for anthracnose management through genome editing and RNA interference technologies. Nevertheless, besides the number of advantages related to their use, e.g., the putative absence of adverse effects due to their high specificity, a number of aspects remain to be clarified to enable their introduction into Integrated Pest Management (IPM) protocols against Colletotrichum spp. disease.

Environmental and human health at risk - Scenarios to achieve the Farm to Fork 50% pesticide reduction goals

The recently released Farm to Fork Strategy of the European Union sets, for the first time, pesticide reduction goals at the EU level: 50% reduction in overall use and risk of chemical pesticides and a 50% use reduction of more hazardous pesticides. However, there is little guidance provided as to how to achieve these targets. In this study, we compiled the characteristics of all 230 EU-approved, synthetic, open-field use active substances (AS) used as herbicides, fungicides and insecticides, and explored the potential of seven Farm to Fork-inspired pesticide use reduction scenarios to achieve the 50% reduction goals. The pesticide reduction scenarios were based on recommended AS application rates, pesticide type, soil persistence, presence on the candidate for substitution list, and hazard to humans and ecosystems. All 230 AS have been found to cause negative effects on humans or ecosystems depending on exposure levels. This is found despite the incomplete hazard profiles of several AS. 'No data available' situations are often observed for the same endpoints and specific organisms. The results of the scenarios indicate that only severe pesticide use restrictions, such as allowing only low-hazard substances, will result in the targeted 50% use and risk reductions. Over half of the 230 AS considered are top use or top hazard substances, however, the reduction actions depend on the still to be defined EC priority areas and action plans, also for other recent and related strategies. Broader scenario implications (on productivity, biodiversity or economy) and the response of farmers to the pesticide use restrictions should be explored in those plans to define effective actions. Our results emphasize the need for a re-evaluation of the approved AS and of their representative uses, and the call for open access to AS, crop and region-specific use data to refine scenarios and assess effective reductions.

ECORISK2050: An Innovative Training Network for predicting the effects of global change on the emission, fate, effects, and risks of chemicals in aquatic ecosystems

By 2050, the global population is predicted to reach nine billion, with almost three quarters living in cities. The road to 2050 will be marked by changes in land use, climate, and the management of water and food across the world. These global changes (GCs) will likely affect the emissions, transport, and fate of chemicals, and thus the exposure of the natural environment to chemicals. ECORISK2050 is a Marie Skłodowska-Curie Innovative Training Network that brings together an interdisciplinary consortium of academic, industry and governmental partners to deliver a new generation of scientists, with the skills required to study and manage the effects of GCs on chemical risks to the aquatic environment. The research and training goals are to: (1) assess how inputs and behaviour of chemicals from agriculture and urban environments are affected by different environmental conditions, and how different GC scenarios will drive changes in chemical risks to human and ecosystem health; (2) identify short-to-medium term adaptation and mitigation strategies, to abate unacceptable increases to risks, and (3) develop tools for use by industry and policymakers for the assessment and management of the impacts of GC-related drivers on chemical risks. This project will deliver the next generation of scientists, consultants, and industry and governmental decision-makers who have the knowledge and skillsets required to address the changing pressures associated with chemicals emitted by agricultural and urban activities, on aquatic systems on the path to 2050 and beyond.

In vivo Antiphytoviral Activity of Essential Oils and Hydrosols From Origanum vulgare, Thymus vulgaris, and Rosmarinus officinalis to Control Zucchini Yellow Mosaic Virus and Tomato Leaf Curl New Delhi Virus in Cucurbita pepo L

In the last decades, the interest in biological activity of natural compounds has been growing. In plant protection, essential oils have been reported to exhibit antiviral, antimycotic, and antiparasitic activities, and are regarded as promising for the formulation of safe antimicrobial agents. Attention has also been focused on hydrosols, the by-products of hydro-distillation of essential oils. Their production is easy, fast, and cheap, and they seem to arise less concern for human health than essential oils. Plant viruses represent a major concern for agricultural crops since no treatment compound is available for virus control. This work was aimed at evaluating the antiphytoviral effectiveness of treatments with three essential oils and corresponding hydrosols extracted from Origanum vulgare, Thymus vulgaris, and Rosmarinus officinalis on Cucurbita pepo plants infected by zucchini yellow mosaic virus or tomato leaf curl New Delhi virus. Treatments were applied either concurrently or after virus inoculation to ascertain an inhibition or curative activity, respectively. Symptoms were observed and samplings were performed weekly. Virus titer and expression levels of phenylalanine ammonia lyase gene (PAL) were measured on treated and untreated infected plants by real-time PCR. PAL gene plays an important role in plant defense response as it is involved in tolerance/resistance to phytopathogens. Results indicated that treatments were effective against tomato leaf curl New Delhi virus whether applied simultaneously with the inoculation or after. A major inhibition was observed with O. vulgare essential oil and hydrosol, resulting in 10^–4-fold decrease of virus titer 3 weeks after treatment. Curative activity gave maximum results with all three essential oils and T. vulgaris and R. officinalis hydrosols, recording from 10^–2-fold decrease to virus not detected 4 weeks after treatment. An induction of PAL gene expression was recorded at 12 d.p.i. and then was restored to the levels of untreated control. This allows to hypothesize an early plant defense response to virus infection, possibly boosted by treatments. Plant extracts’ composition was characterized by gas chromatography-mass spectrometry. Phenols were largely main components of O. vulgare and T. vulgaris extracts (carvacrol and thymol, respectively), while extracts from R. officinalis were based on monoterpene hydrocarbons (essential oil) and oxygenated monoterpenes (hydrosol).

Does the certification of agriculture products promote the adoption of integrated pest management among apple growers in China?

Seeking effective policies for reducing chemical pesticides has recently been the focus of agricultural sustainable development. A randomly selected sample of 559 small-scale farmers on the China Loess Plateau was investigated in 2018. We analyzed the effect of certification of agricultural production on the adoption of integrated pest management (IPM) by using the Poisson regression model. The result shows that the certification of agriculture products, subsidies of integrated pest management, and the price increase of certified agriculture products significantly promote the adoption of IPM. However, government supervision in certified agriculture products does not significantly promote the adoption of IPM. The cognition of IPM acquired by farmers significantly promotes the adoption of IPM, while the age of farmers negatively affects the adoption of IPM. We suggest that the government should strengthen the certification of agriculture products and provide subsidies of the adoption of IPM for farmers who produce certified agriculture products. The market needs to guarantee a higher price of certified agro-products which the IPM are adopted. The government should strengthen supervision of certified agriculture products, promote the extension of IPM and enhance farmers' knowledge of IPM, and promote more farmers to replace chemical pesticides with IPM.

Sensitivity Testing of Natural Antifungal Agents on Fusarium fujikuroi to Investigate the Potential for Sustainable Control of Kiwifruit Leaf Spot Disease

Kiwifruit is a nutritious and economically important fruit that is widely cultivated in China. In 2021, leaf spot disease of kiwifruit was discovered in the main kiwifruit-producing area of Xifeng County, Guizhou Province, China. Leaf spot disease weakens plant photosynthesis and reduces nutrient synthesis, thereby affecting plant growth. We studied the morphological characteristics and performed a combined analysis of EF-1α, RPB2, and TUB2 genes of Fusarium fujikuroi, a fungus associated with leaf spot disease. The pathogenicity of F. fujikuroi followed Koch’s hypothesis, confirming that this fungus is the cause of kiwifruit leaf spot disease. The sensitivity of seven natural antifungal agents against F. fujikuroi was measured using the mycelial growth rate method. Honokiol, cinnamaldehyde, and osthol showed good antifungal effects against F. fujikuroi, with EC50 values of 18.50, 64.60, and 64.86 μg/mL, respectively. The regression coefficient of cinnamaldehyde was the largest at 2.23, while that of honokiol was the smallest at 0.408. Fusarium fujikuroi was the most sensitive to cinnamaldehyde.

Pesticide dose adjustment in fruit and grapevine orchards by DOSA3D: Fundamentals of the system and on-farm validation

Agricultural productivity cannot be sustained without the application of plant protection measures. Within the framework of integrated pest management (IPM), the use of chemical pesticides should be limited to the last option among the available practices. Even though their use remains common, it carries associated environmental and human health risks. One of the most accepted practices within IPM is the reduction of spraying events and/or pesticide applied doses. DOSA3D is a decision support system that allows the dose to be adjusted to the specific treatment scenario. For this, DOSA3D calculates the optimal application volume rate by estimating the leaf area index and takes into account the overall spraying efficiency and the pest or disease to be controlled. The system adopts specific minimum volume rates for fruit trees and vineyards without compromising the crop health status. To establish the adjusted dose, the labeled or the adviser prescription concentration is kept. Resulting adjusted doses provided by DOSA3D achieved pesticide savings up to 53% in fruit trees and 60% in vineyards. DOSA3D has been validated against the main diseases and pests of fruit trees and vineyards: brown spot and psylla in pear orchards; alternaria blotch disease, apple scab, codling moth, oriental moth and red spider mite in apple orchards; powdery mildew, brown rot, aphids, thrips and mites in peach orchards; and, powdery mildew, yellow spider mite and leafhoppers in grapevine orchards. In addition, a methodology called Green Way is presented to provide consistent and crop safety pesticide doses when these are labeled as concentration or ground area doses.

Effect of host plant on the life history of the carnation tortrix moth Cacoecimorpha pronubana (Lepidoptera: Tortricidae)

The carnation tortrix moth, Cacoecimorpha pronubana (Hübner, [1799]) (Lepidoptera: Tortricidae), is one of the most economically important insect species affecting the horticultural industry in the UK. The larvae consume foliage, flowers or fruits, and/or rolls leaves together with silken threads, negatively affecting the growth and/or aesthetics of the crop. In order to understand the polyphagous behaviour of this species within an ornamental crop habitat, we hypothesized that different host plant species affect its life history traits differently. This study investigated the effects of the host plant species on larval and pupal durations and sizes, and fecundity (the number of eggs and the number and size of egg clutches). At 20°C, 60% RH and a 16L:8D photoperiod larvae developed 10, 14, 20 and 36 days faster when reared on Christmas berry, Photinia (Rosaceae), than on cherry laurel, Prunus laurocerasus (Rosaceae), New Zealand broadleaf, Griselinia littoralis (Griseliniaceae), Mexican orange, Choisya ternata (Rutaceae), and firethorn, Pyracantha angustifolia (Rosaceae), respectively. Female pupae were 23.8 mg heavier than male pupae, and pupal weight was significantly correlated with the duration of larval development. The lowest and the highest mean numbers of eggs were produced by females reared on Pyracantha (41) and Photinia (202), respectively. Clutch size differed significantly among moths reared on different host plants, although the total number of eggs did not differ. This study showed that different ornamental host plants affect the development of C. pronubana differently. Improved understanding of the influence of host plant on the moth's life history parameters measured here will help in determining the economic impact that this species may have within the ornamental plant production environment, and may be used in developing more accurate crop protection methodologies within integrated pest management of this insect.

In Vitro Potential of Clary Sage and Coriander Essential Oils as Crop Protection and Post-Harvest Decay Control Products

Owing to their various application fields and biological properties, natural products and essential oils (EO) in particular are nowadays attracting more attention as alternative methods to control plant pathogens and pests, weeds, and for post-harvest applications. Additionally, to overcome EO stability issues and low persistence of effects, EO encapsulation in β-cyclodextrin (β-CD) could represent a promising avenue. Thus, in this work, the EO distilled from two aromatic plants (Salvia sclarea L. and Coriandrum sativum L.) have been evaluated in vitro for their antifungal, herbicidal and insecticidal activities, against major plant pathogens and pests of agronomical importance. Both plants were grown on unpolluted and trace-element-polluted soils, so as to investigate the effect of the soil pollution on the EO compositions and biological effects. These EO are rich in oxygenated monoterpenes (clary sage and coriander seeds EO), or aliphatic aldehydes (coriander aerial parts EO), and were unaltered by the soil pollution. The tested EO successfully inhibited the growth of two phytopathogenic fungi, Zymoseptoria tritici and Fusarium culmorum, displaying IC₅₀ ranging from 0.46 to 2.08 g L⁻¹, while also exerting anti-germinative, herbicidal, repellent and fumigant effects. However, no improvement of the EO biological effects was observed in the presence of β-CD, under these in vitro experimental conditions. Among the tested EO, the one from aerial parts of coriander displayed the most significant antifungal and herbicidal effects, while the three of them exerted valuable broad-range insecticidal effects. As a whole, these findings suggest that EO produced on polluted areas can be of great interest to the agricultural area, given their faithful chemical compositions and valuable biological effects.

Screening of Antimicrobial Activities and Lipopeptide Production of Endophytic Bacteria Isolated from Vetiver Roots

The exploration of certain microbial resources such as beneficial endophytic microorganisms is considered a promising strategy for the discovery of new antimicrobial compounds for the pharmaceutical industries and agriculture. Thirty-one endophytic bacterial strains affiliated with Bacillus, Janthinobacterium, Yokenella, Enterobacter, Pseudomonas, Serratia, and Microbacterium were previously isolated from vetiver (Chrysopogon zizanioides (L.) Roberty) roots. These endophytes showed antifungal activity against Fusarium graminearum and could be a source of antimicrobial metabolites. In this study, in particular, using high-throughput screening, we analyzed their antagonistic activities and those of their cell-free culture supernatants against three species of Fusarium plant pathogens, a bacterial strain of Escherichia coli, and a yeast strain of Saccharomyces cerevisiae, as well as their capacity to produce lipopeptides. The results showed that the culture supernatants of four strains close to B. subtilis species exhibited antimicrobial activities against Fusarium species and E. coli. Using mass spectrometry analyses, we identified two groups of lipopeptides (surfactins and plipastatins) in their culture supernatants. Whole-genome sequencing confirmed that these bacteria possess NRPS gene clusters for surfactin and plipastatin. In vitro tests confirmed the inhibitory effect of plipastatin alone or in combination with surfactin against the three Fusarium species.

Optimising Vine Weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae), Monitoring Tool Design

Simple Summary

Vine weevil remains one of the most economically important insect pests of soft-fruit and ornamental crops globally. Growers currently lack effective monitoring systems to determine presence of vine weevil within crops, meaning that controls are often applied too late to prevent economic losses. Development of improved monitoring systems is currently hindered by a lack of knowledge of whether vine weevil adults select a monitoring tool based on its visual appearance. This study used paper cups as refuges to investigate the importance of colour, shape and position of entrances on monitoring tool efficacy. Results indicate that dark, tall refuges with entrances around their base were preferentially entered by adult vine weevil. This information provides the first steps towards developing improved designs for vine weevil monitoring tools.

Abstract

Vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae), is an economically important insect pest of horticultural crops. To identify an effective and reliable monitoring system for adult vine weevil, this study investigated the influence of colour, height and entrance position on the efficacy of a model monitoring tool using modified paper cups as refuges. Vine weevil preferences were determined by the number of individuals recorded within a refuge. When provided with a binary choice between black or white refuges, vine weevil adults showed a preference for black refuges. Vine weevils provided with a range of coloured refuges (blue, green, red and yellow) in addition to black and white refuges showed a preference for black and blue over the other colours and white refuges in group choice experiments. Refuge height and entrance position also influenced vine weevil behaviour with individuals exhibiting a preference for taller refuges and those with entrance openings around the refuge base. These results provide insights into refuge selection by adult vine weevils, which can be exploited to improve monitoring tool design. The importance of developing an effective monitoring tool for vine weevil adults as part of an integrated pest management programme is discussed.

Suitable Areas for Apiculture Expansion Determined by Antioxidant Power, Chemical Profiles, and Pesticide Residues in Caldcluvia paniculata Honey and Beeswax Samples

Forty-two samples of Tiaca Honey (Caldcluvia paniculata) obtained from beehives belonging to 14 apiaries (three honey samples per apiary) were collected at the end of January near Osorno (40°34′ S, 73°8′ W), Puyehue (40°40′ S, 72°37′ W) and Frutillar 41°7′ S, 72°59′ W) covering an area of 1240 km2. They presented the highest phenol contents (0.36 mg gallic acid equivalent/kg) and antioxidant power (1.27 mM equivalent of Fe+2/g of sample), and were among the highest for antiradical activity. Phenol contents and antioxidant power (r = 0.72, p-value < 0.01) and total phenol contents and antiradical activity (r = 0.69; p-value < 0.01) displayed linear correlations. Only two beeswax samples showed residues of the pesticide fenhexamid. The respective sites (Purranque [40°55′ S, 73°10′ W] and Coligual [40°49′ S, 72°54′ W]) were the only areas located near active farms. Additionally, the m/z value 163.1091 was found as an element to identify honeys. Data were used to construct a mapped suitability index ranking for pesticide-free areas with high biological quality. The provided chemical profiles will aid local beekeepers in obtaining international certifications, particularly for the EU market. In turn, the constructed maps indicate suitable areas for apiculture expansion, while differentiated pesticide detection in honey and beeswax requires further comparative research.