Search Results (107)

Postharvest losses of Solanaceae crops, which include potatoes (Solanum tuberosum), tomatoes (Solanum lycopersicum), bell peppers (Capsicum annuum), and others, are one of the major challenges in agriculture throughout the world, impacting food security and economic viability. Agrochemicals have been successfully employed to prevent postharvest losses in agriculture. However, the excessive use of agrochemicals may cause detrimental effects on consumer health, the emergence of pesticide-resistant pathogens, increased restrictions on existing pesticides, environmental harm, and the decline of beneficial microorganisms, such as natural antagonists to pests and pathogens. Hence, there is a need to search for a safer and more environmentally friendly alternative. Microbial antagonists have gained more attention in recent years as substitutes for the management of pests and pathogens because they minimize the excessive applications of toxic substances while providing a sustainable approach to plant health management. However, more research is required to make microbial agents more stable and effective and less toxic before they can be used in commercial settings. Therefore, research is being conducted to develop new biological control agents and obtain knowledge of the mechanisms of action that underlie biological disease control. To accomplish this objective, the review aims to investigate microbial antagonists’ modes of action, potential future applications for biological control agents, and difficulties encountered during the commercialization process. We also highlight earlier publications on the function of microbial biological control agents against postharvest crop diseases. Therefore, we can emphasize that the prospects for biological control are promising and that the use of biological control agents to control crop diseases can benefit the environment. Full article

The environment is a complex system composed of various creatures and pollutants caused by human activity. In this study, a mixture toxicity assessment based on the concentration-addition (CA) model was applied to 51 types of pesticides detected in the Saemangeum Watershed (the Mangyeong and Dongjin Rivers) for one year to evaluate pollution levels. A mixture toxicity assessment was conducted based on the measured environmental concentration (MEC) and the predictive values of basic ecotoxicity data (algae, daphnids, and fish). The risk and the trophic levels that showed the highest sensitivity varied depending on the sampling time and point for each mode of action (MoA) group of pesticides. In particular, the mixture risk for chloroacetamide and thiocarbamate pesticides was high (risk quotient > 1), and the potential risk was highest in autumn. In addition, the driving forces of seasonal changes were examined for samples that exhibited potential risks, and it was found that one to four substances contributed the most to the risk. The results of this study show that an initial risk assessment based on a mixture toxicity assessment can help in managing pesticide pollution in rivers. Full article

Lantana camara is weed with a wide range of chemical constituents, including primary and secondary metabolites such as alkaloids, flavonoids, tannins, saponins, and terpenoids. These compounds contribute to its medicinal and pesticidal potential. The essential oils and different solvent fractions derived from L. camara exhibit notable variations in their respective chemical compositions across various plant parts, spatial distributions, and interspecific comparisons. The principal components, notably lantadene A, lantadene B, lantadene C, lantadene D, β-caryophyllene, α-humulene, and several others, constitute a significant portion of the essential oil derived from the leaves and flowers. Researchers have discovered that L. camara oil exhibits potent insecticidal activity against a range of pests, with variations in potency observed across different seasons due to changes in chemical composition. In addition to the essential oils, solvent extracts of L. camara, primarily methanolic extracts of the leaves of this species, demonstrate considerable potential as fumigant and contact toxins for stored grain pests. However, these have been comparatively less characterized with respect to their insecticidal properties, particularly in comparison to the essential oils. Molecular docking studies have demonstrated that phytochemical compounds present in the plants interfere with the activity of several enzymes that are responsible for the growth and survival of insects. For example, compounds such as β-caryophyllene and linalool exhibited a high binding affinity to AChE, thereby enhancing its neurotoxic effects. In conclusion, this review identifies L. camara as a natural insecticide with a complex set of modes of action attributed to its rich phytochemical profile. The integration of traditional knowledge with modern molecular techniques might expose avenues for the sustainable management of pests and control, ultimately making L. camara a key resource for such applications. Further studies are necessary to characterize such bioactive compounds and their uses in controlling pests in agricultural operations. Full article

Recently, a large number of pesticides with different chemical structures and modes of action (MOAs) have become regularly used in agriculture. They are used to control the insect populations in various crops. Foliar application of pesticides may negatively affect crop physiology, especially photosynthesis. However, the sensitivity of particular crops, especially their primary and secondary photosynthetic processes, to insecticide application is generally unknown. Our study aimed to evaluate the negative effects of lambda-cyhalothrin (λ-CY) on photosystem II (PSII) in Malva moschata (Musk mallow). We used fast chlorophyll fluorescence transients (i.e., OJIPs) and OJIP-derived parameters, the effective quantum yield of PSII (Φ_PSII), induction curves of non-photochemical quenching (NPQ) and spectral reflectance curves and indices. The recommended concentration (0.05 μM) and a 10 times higher concentration (0.5 μM) of λ-CY did not cause any negative effect on photosynthetic parameters. An overdosed foliar application (100 times higher than recommended, i.e., 50 μM) led to changes in OJIP shape; a decrease in performance index (PI_ABS), maximum photosynthetic yield (F_V/F_M) and photosynthetic electron transport (ET₀/RC); and an increase in protective mechanisms (unregulated quenching, DI₀/RC). These changes lasted only tens of minutes after application, after which the parameters returned to pre-application values. An overdosed λ-CY application caused more rapid activation of NPQ, indicating the early response to stress in PSII. The application of 50 μM λ-CY caused an increase in spectral reflectance above 720 nm and changes in the indices that indicated λ-CY-induced stress. Full article

Bemisia tabaci (Gennadius) is a major pest worldwide, causing damage to a vast range of plants through its feeding on phloem sap and its vectoring of >100 plant viruses. Although not established in the UK, it is regularly introduced on planting material, which poses a significant plant health risk. Restrictions on pesticide use and increasing resistance to available active ingredients limit options for effective control of potential outbreaks. Alternative management options are required to mitigate this risk. There was high variability in the efficacy of the different modes of action products tested against two life stages (adults and larvae) as well as the Middle East–Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of B. tabaci. For both adults and larvae, MEAM1 were more susceptible than MED insects, possibly due to differences in resistance developed against some active ingredients. All products tested were effective to varying degrees against MEAM1 adults with Tracer (spinosad), PREV-AM (orange oil), Sequoia (sulfoxaflor), and FLiPPER (fatty acids) having similar efficacies (59–78% mortality). In contrast, PREV-AM and FLiPPER were most effective against MED adults (74% and 65% mortalities, respectively). Both MED and MEAM1 larvae were highly susceptible to FLiPPER and PREV-AM (>95% mortality), and the efficacy of Tracer and FLiPPER can be enhanced by using in combination with PREV-AM, and this can be achieved by using low doses of each product. Synergy was measured between PREV-AM and Tracer against MEAM1 larvae, which has the potential to provide effective control with a reduced pesticide application. Full article

The longhorned tick (LHT), Haemaphysalis longicornis Neumann (Acari: Ixodidae), is a serious invasive pest in North America where its geographical range is expanding with high densities associated with commercial animal production. There are only a few chemical pesticides available for LHT control, which can lead to the evolution of resistant strains. Diatomaceous earth (DE) was shown to be effective in killing some important tick species but was not examined for LHTs. When LHT nymphs were dipped for about 2–4 s into DE, transferred to Petri dishes (one tick/dish), and incubated at 30 °C and 70% relative humidity, the median survival time was 4.5 h. A locomotor activity assay showed that there was no difference in the overall distance traveled between the DE-treated and control ticks except during the first 2 h after exposure. In a field-simulated study in which a dose of 5.0 g DE/m² was applied to pine needle litter infested with LHT, all the LHTs were dead at 24 h with no control mortality. Scanning electron micrographs showed the mineral adhering to all surfaces of the tick. The results indicated that DE is effective in killing nymphal LHTs and could be an alternative to the use of chemical acaricides with the advantage of managing pesticide resistance through the killing by a different mode of action and could be used for organically certified animal husbandry. Full article

Sustainable agriculture aims to use biological resources to improve crop quality and productivity. This approach promotes alternatives, such as replacing synthetic pesticides with biological ones and substituting mineral fertilizers with organic fertilizers. Field trials were conducted using two different factors: fertilizer treatments (ammonium nitrate and pig manure digestate) and plant protection treatments (pesticides, Artemisia dubia Wall biomass mulch, and strips). After harvesting the winter wheat, the productivity and quality (weight of 1000 grains, protein, gluten, starch, sedimentation of grains) were evaluated. The two-year studies showed that pig manure digestate positively affected winter wheat grain quality. Mugwort biomass outperformed other plant protection options in three key grain quality indicators (protein, gluten, and sedimentation). Furthermore, in 2023, the highest grain yield of 5798 ± 125 kg ha⁻¹ was observed in the pesticides and pig manure digestate treatment. The quick impact and mode of action of vegetation pesticides were more easily felt over the two years of study, leading to the highest yield of wheat grains compared to other plant management measures. This study shows that mugwort biomass can positively influence wheat grain quality, a significant milestone in utilizing nonfood crops as alternatives for agricultural productivity. Full article

A century after the first scientific research on the chemical structures of pyrethrins was published (in 1923), this paper aims to provide an exhaustive review of the historical research pathways and relative turning points that led to the discovery and mass production of pyrethroids, which have become among the most commercially successful insecticides. These compounds, which are not specific to any particular pest, are used globally and offer cost-effective advantages against a broad spectrum of pests in both agricultural and non-agricultural situations. They are utilized in the context of both harvest and post-harvest applications, as well as in the implementation of public health programs and veterinary applications. Currently, the research for new pyrethroids has essentially reached a standstill due to the increasingly widespread occurrence of insecticide resistance in pests. Nevertheless, several research paths remain open regarding these pesticides. This paper represents the current state of knowledge regarding pyrethroids, exposing both their advantages and disadvantages. Moreover, further investigation, at the molecular level, on their mode of action (MoA) could be very useful to improve their specificity. The results of this review may stimulate additional research for the development of novel pyrethroids having enhanced efficacy, low cost and reduced environmental impact. Full article

Pesticides affect biota inside and outside agricultural fields due to their intrinsic mode of action. This study investigated whether pesticide active substances (AS) approved for conventional agriculture in Europe differ in their ecotoxicity from AS approved for organic agriculture. The evaluation was based on official ecotoxicological data for surrogate honeybee, bird, and earthworm species, which also serve as a reference for official environmental risk assessments in the pesticide authorization process. In October 2022, 268 chemical-synthetic AS approved for conventional and 179 nature-based AS approved for organic agriculture were listed in the EU Pesticide Database. Ecotoxicological data were only available for 254 AS approved for use in conventional agriculture and 110 AS approved for use in organic agriculture. The results showed a higher ecotoxicity of conventional AS: 79% (201 AS), 64% (163 AS) and 91% (230 AS) were moderately to acutely toxic to honeybees, birds, and earthworms, respectively, compared to 44% (48 AS), 14% (15 AS) and 36% (39 AS) of AS approved for organic agriculture. We have only considered the potential ecotoxicities of individual substances in this assessment; actual exposure in the field, where multiple AS formulations with other chemicals (including impurities) are applied, will be different. Nevertheless, these results emphasize that an increase in organic agriculture in Europe would reduce the ecotoxicological burden on biodiversity and associated ecosystem services. Full article

Specialized chemicals are used for intensifying food production, including boosting meat and crop yields. Among the applied formulations, antibiotics and pesticides pose a severe threat to the natural balance of the ecosystem, as they either contribute to the development of multidrug resistance among pathogens or exhibit ecotoxic and mutagenic actions of a persistent character. Recently, cold atmospheric pressure plasmas (CAPPs) have emerged as promising technologies for degradation of these organic pollutants. CAPP-based technologies show eco-friendliness and potency for the removal of organic pollutants of diverse chemical formulas and different modes of action. For this reason, various types of CAPP-based systems are presented in this review and assessed in terms of their constructions, types of discharges, operating parameters, and efficiencies in the degradation of antibiotics and persistent organic pollutants. Additionally, the key role of reactive oxygen and nitrogen species (RONS) is highlighted. Moreover, optimization of the CAPP operating parameters seems crucial to effectively remove contaminants. Finally, the CAPP-related paths and technologies are further considered in terms of biological and environmental effects associated with the treatments, including changes in antibacterial properties and toxicity of the exposed solutions, as well as the potential of the CAPP-based strategies for limiting the spread of multidrug resistance. Full article

Aquatic ecosystems can suffer inadvertent contamination from widely used herbicides. This study delves into the relative toxicity of 36 herbicides on green algae, exploring 11 distinct modes of action and 25 chemical structure classes. Through a 72-h algal growth inhibition test, it was found that herbicides targeting acetolactate synthase (ALS), photosystem II (PSII inhibitors), microtubule assembly, very-long-chain fatty acid (VLCFA) synthesis, and lipid synthesis exhibited high toxicity, with 72-h EC50 (half-maximal effective concentration) values ranging from 0.003 mg/L to 24.6 mg/L. Other pesticide types showed moderate to low toxicity, with EC50 values ranging from 0.59 mg/L to 143 mg/L. Interestingly, herbicides sharing the same mode of action but differing in chemical composition displayed significantly varied toxicity. For instance, penoxsulam and pyribenzoxim, both ALS inhibitors, demonstrated distinct toxicity levels. Similarly, terbuthylazine and bentazone, both PSII inhibitors, also exhibited differing toxicities. Notably, herbicides approved for rice cultivation showed lower toxicity to green algae compared to those intended for terrestrial plants. These data offer valuable insights for assessing the potential risks posed by these chemicals to aquatic organisms. Additionally, to prevent or minimize herbicide residual effects, modern management practices were reviewed to offer practical guidance. Full article

Drug discovery was initially attributed to coincidence or experimental research. Historically, the traditional approaches were complex, lengthy, and expensive, entailing costly random screening of synthesized compounds or natural products coupled with in vivo validation largely depending on the availability of appropriate animal models. Currently, in silico modeling has become a vital tool for drug discovery and repurposing. Molecular docking and dynamic simulations are being used to find the best match between a ligand and a molecule, an approach that could help predict the biomolecular interactions between the drug and the target host. Beauvericin (BEA) is an emerging mycotoxin produced by the entomopathogenic fungus Beauveria bassiana, being originally studied for its potential use as a pesticide. BEA is now considered a molecule of interest for its possible use in diverse biotechnological applications in the pharmaceutical industry and medicine. In this manuscript, we provide an overview of the repurposing of BEA as a potential therapeutic agent for multiple diseases. Furthermore, considerable emphasis is given to the fundamental role of in silico techniques to (i) further investigate the activity spectrum of BEA, a secondary metabolite, and (ii) elucidate its mode of action. Full article

Synthetic herbicides, with their varying modes of action, are well known for their efficiency in the suppression and control of weed species in U.S. agriculture. However, the consequences of using synthetic herbicides without attention to the surrounding environment produce chemical run-off, changes in soil health and soil health conditions, and create herbicide-resistant weeds. These outcomes have encouraged growers to seek alternative methods for their weed management programs or farming operations. Organic production systems and organic pesticides have helped address these challenges related to sustainability and environmental health. However, the use of organic herbicides in a conventional cropping system is not usually evaluated, as the effectiveness of these organic herbicides on weed populations in such a setting is thought to be inferior when compared to their synthetic counterparts. In this study, organic and synthetic herbicides were assessed on their performance in weed suppression surveys. The experimental design included nine treatments with four replications on two different soil types. The results showed organic herbicides were not comparable to synthetic herbicides in weed suppression. In weed management programs, using recommended herbicide application rates outlined on the herbicide label and conducting applications with environmental stewardship in mind could decrease possible herbicide effects within the environment. Full article

Pesticide overuse in agricultural systems has resulted in the development of pest resistance, the impoverishment of soil microbiota, water pollution, and several human health issues. Nonetheless, farmers still depend heavily on these agrochemicals for economically viable production, given the high frequency at which crops are affected by pests. Phytopathogenic insects are considered the most destructive pests on crops. Botanical pesticides have gained attention as potential biopesticides and complements to traditional pesticides, owing to their biodegradability and low toxicity. Plant-based extracts are abundant in a wide variety of bioactive compounds, such as flavonoids, a class of polyphenols that have been extensively studied for this purpose because of their involvement in plant defense responses. The present review offers a comprehensive review of current research on the potential of flavonoids as insecticides for crop protection, addressing the modes and possible mechanisms of action underlying their bioactivity. The structure–activity relationship is also discussed. It also addresses challenges associated with their application in pest and disease management and suggests alternatives to overcome these issues. Full article

The comment titled “Factors related to Bacillus thuringiensis and gut physiology” disputes some of the inferences in the paper “An Alkaline Foregut Protects Herbivores from Latex in Forage, but Increases Their Susceptibility to Bt Endotoxin” published in this journal. The key points in the dissent are the following: 1. Bt is generally safe to non-target species. 2. Transgenic Bt crops provide additional ecological benefits due to reductions in conventional pesticide use. 3. Susceptibility to Bt does not indicate alkalinity, nor vice versa. My response is summarized as follows: 1. Bt can form non-specific pores at concentrations of 100 ng/mL in culture, and so is potentially unsafe for animals with gut environments in which Bt persists at or above this level. 2. Initial reductions in insecticide applications have not been sustained and are even increasing in areas planted with transgenic Bt cotton. 3. Acidic guts degrade Bt more efficiently, but I concede that gut alkalinity does not imply susceptibility to Bt due to many factors including resistance in target species, toxin heterogeneity and variable modes of action. However, the susceptibility of foregut-fermenting herbivores with alkaline guts to Bt intoxication cannot be invalidated without further study. Full article