Agrochemicals doi: 10.3390/agrochemicals5020029

Authors: Stephen Arthur Grace Bolfrey-Arku David L. Jordan Joseph Sarkodie-Addo Richard Akromah Moses Brandford Mochiah Afua G. Gyimah Frank Bondinuba Victoria Klutse Maxwell Yorke

Protecting peanut (Arachis hypogaea L.) from weed interference is important for optimizing yield in Ghana and other West African countries. Hand removal is the main approach for controlling weeds in this region of the world. Herbicides are an alternative to hand weeding. Information on the balance between herbicides and hand labor required to control weeds is limited. To address this, research was conducted to determine weed biomass, peanut yield, time required to remove weeds by hand and apply herbicides, and financial return when metolachlor was applied immediately after seeding (preemergence), imazethapyr was applied 4 weeks after seeding (postemergence), and both herbicides were applied either with or without hand weeding. Controls without weed management and hand removal of weeds without herbicides were included. Weed biomass was the lowest and peanut yield the highest when herbicides and hand weeding were included and when hand weeding was performed twice without herbicides. Herbicides were only less effective than combinations of herbicides and hand weeding. For weed management approaches that resulted in the greatest financial return, the time required for weeding was reduced from 44.5 workdays/ha for hand weeding twice to 14.1, 17.5, and 16.0 workdays/ha for preemergence herbicide plus hand weeding, postemergence herbicide plus hand weeding, and both herbicide timings plus hand weeding, respectively. These results indicate that the combination of preemergence and postemergence herbicides and the combination of herbicide and hand weeding protect peanut yield as well as hand weeding twice. Although herbicides resulted in less labor allocated for weed management, proper stewardship of herbicide use is needed to protect farm workers and decrease potential negative impact on the environment and reduce risk from herbicide residues in peanut-based foods to consumers.

Agrochemicals doi: 10.3390/agrochemicals5020028

Authors: Silas Wintuma Avicor Godfred Kweku Awudzi Kwabena Owusu Baffoe Akua Konadu Antwi-Agyakwa Thomas Buxton Ebenezer Oduro Owusu

Although information on insecticide toxicity on pests abounds, this is limited on non-target organisms like ants in cocoa production systems. This study determined the toxicity of insecticides (containing acetamiprid 40 g L−1 EW, acetamiprid 64 g L−1 + emamectin benzoate 48 g L−1 EC, acetamiprid 20 g L−1 + lambda-cyhalothrin 15 g L−1 SC, emamectin benzoate 5% WDG and pyrethrins 50 g L−1 EW) used against cocoa pests on non-target predatory ants (Crematogaster africana, Oecophylla longinoda and Pheidole megacephala) under laboratory (using filter-paper method) and field conditions to identify less harmful products for use in the cropping system. Ant knockdown and mortality varied significantly among insecticides at their recommended rates, with emamectin benzoate being the least toxic and acetamiprid + lambda-cyhalothrin the most toxic. LC95s varied significantly, with emamectin benzoate having the highest predator safety index, while pyrethrins had the lowest. Generally, selectivity towards O. longinoda was higher than that towards the other ants. In the field, emamectin benzoate had the least acute adverse effect on ant abundance. Ant population generally rebounded to pre-treatment levels at 1 month after the last insecticide application. The study indicates differential toxicity and identifies ant-compatible insecticide options contingent on the autochthonous ant composition.

Agrochemicals doi: 10.3390/agrochemicals5020027

Authors: Maipato Margaret Mota Elmarie Van Der Watt Zenzile Peter Khetsha

Mesotrione is a herbicide used in field crops to control grass and broadleaf weeds worldwide. For grain crops such as maize, mesotrione is recommended for a waiting period of up to 24 months before planting. This research builds on earlier investigations that explored the influence of brassinosteroids on soybean and other legume species. Hence, the study aimed to determine the effects of mesotrione residues on morpho-physiological and yield parameters of a brassinosteroid-treated soya bean. The experiment was a pot trial, laid out in a completely randomized block design, arranged in a 4 × 2 factorial design. Mesotrione was applied at concentrations of 1.6 µg.ai kg−1 soil, equivalent to 45 days after application (DAA), 0.05 µg.ai kg−1 soil (90 DAA), and 0.0016 µg.ai kg−1 soil (135 DAA), with untreated plants as the control. With increasing concentration, symptoms ranged from bleaching and necrosis to higher concentrations. Furthermore, findings in this study suggest that the combination of mesotrione (at 0.0016 µg.ai kg−1) and recommended application rate of brassinosteroid plays an important role in improving nutrient uptake, resulting in increased plant growth, physiology, and yield. It could be concluded from the measured and visually observed parameters that mesotrione beyond 0.0016 µg.ai kg−1 concentration resulted in negative effects on the plant growth, physiology, and yield; thus, a mitigating strategy using eco-organic production systems with different levels of brassinosteroids to improve soya bean treated with mesotrione should be prioritized as a future study.

Agrochemicals doi: 10.3390/agrochemicals5020026

Authors: Juan E. Fierro-Cruz Willy Cely-Veloza Ericsson Coy-Barrera

Phytopathogenic fungi cause major agricultural losses worldwide. Their control relies largely on synthetic fungicides, which raise concerns related to environmental impact, resistance development, and human health. Botanical extracts represent a promising, sustainable alternative, and members of the Brassicaceae family are recognized as rich sources of antifungal metabolites. In this study, the antifungal activity of ethanol extracts from Brassica napus and Capsella bursa-pastoris was evaluated against Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum, which are major phytopathogens widely recognized for causing significant diseases in diverse commercial crops worldwide. Antifungal effects on mycelial radial growth and conidial production were assessed in vitro using the amended culture medium assay. Extracts were chemically characterized by LC-DAD-ESI-MS, and a single-Y orthogonal partial least squares (OPLS) analysis was applied to integrate chemical and bioactivity data to identify metabolites associated with antifungal activity. Test botanical extracts showed organ- and pathogen-dependent antifungal activity. B. napus was more active, as seeds reduced B. cinerea growth, and roots strongly suppressed conidiation and inhibited F. oxysporum. In contrast, C. bursa-pastoris was less effective, with only the flower and fruit extracts causing modest reductions in F. oxysporum, while the other extracts were largely inactive. Fourteen metabolites were tentatively identified based on UV-Vis and mass spectral data. Among them, one flavanol and two indole-containing compounds were statistically correlated with antifungal activity, were subsequently isolated, and were structurally confirmed by NMR spectroscopy. These compounds (1–3) exhibited reasonable antifungal activity (IC50 < 40 µM). The integrative covariate-based metabolic profiling approach proved operative for identifying bioactive constituents in the test botanical extracts, supporting the potential of Brassicaceae-derived extracts and their metabolites as natural antifungal agents.

Agrochemicals doi: 10.3390/agrochemicals5020025

Authors: João Paulo Arantes Rodrigues da Cunha Erdal Ozkan Hongyoung Jeon

Although a pulse-width modulation (PWM) technique controls nozzle flow rate with minimal pressure variation, its effects on droplet size distribution and flow regulation when combined with low-drift nozzle designs are still not well documented. Therefore, the objective of this research was to investigate the effects of PWM on droplet size distribution and flow rate of low-drift nozzles used in pesticide application systems. Experiments were conducted under controlled laboratory conditions to evaluate eight flat-fan nozzles with different designs to increase spray droplet sizes. Each nozzle was coupled with a PWM valve, and tested at duty cycles (DUC) from 20% to 100% in 20% increments, and operating pressures of 276 and 414 kPa. Droplet size distribution was determined using a laser diffraction technique, and nozzle flow rate was evaluated to assess the effects of DUC on spray characteristics. PWM operation showed a strong linear relationship between DUC and flow rate (R2 ≥ 0.99). In addition, measured flow rates showed good agreement with theoretical values at DUCs ≥ 60%, whereas substantial deviations were observed at lower DUCs. The effects of DUC on droplet size characteristics varied by nozzle design, pressure, and the parameter evaluated. Low DUCs tended to increase droplet size heterogeneity and the proportion of drift-prone droplets (<150 µm), although these effects were dependent on nozzle type and operating pressure and were not observed consistently across all nozzles. Overall, excessively low DUCs may compromise flow accuracy and spray quality in PWM systems.

Agrochemicals doi: 10.3390/agrochemicals5020024

Authors: Nicolas Buck Elizeth Cinto Mejia Nicole Louise Nicola Frank G. Zalom

Spotted-wing Drosophila (Drosophila suzukii), an economically important invasive but widely distributed pest, has developed resistance to multiple insecticide classes, threatening its management in commercial soft fruit production. This study evaluated the synergism of piperonyl butoxide (PBO) with zeta-cypermethrin in two field-collected resistant California populations and a susceptible population with bioassays. Female flies from the two resistant populations exhibited 55-fold and 25-fold resistance, respectively, compared to the susceptible population. PBO co-application significantly enhanced insecticide efficacy in both resistant populations, with synergism ratios of 6.51 and 4.06. However, complete susceptibility at label rates of the insecticide was not restored, indicating that other resistance mechanisms may also be present in these populations. PBO–pyrethroid combinations show promise for improving field efficacy against resistant populations, though they should be integrated with insecticide rotation and other integrated pest management tactics for sustainable resistance management.

Agrochemicals doi: 10.3390/agrochemicals5020023

Authors: Adeney de F. Bueno William W. Hoback Ivair Valmorbida Yelitza C. Colmenarez Weidson P. Sutil Lian-Sheng Zang

Global population growth has increased the demand for food production and, therefore, for higher crop yields, especially for soybean, which is one of the most cost-effective and affordable sources of high-quality protein for animal and human nutrition. This frequently leads to an overuse of traditional chemical insecticides to maximize yields, thereby triggering negative side effects. However, both consumers and governments around the world demand a reduction in chemical insecticides in agriculture. To address this challenge, pest control must be guided by proper adoption of economic thresholds (ETs), which indicate the most appropriate time to initiate control in the crop. Despite the well-documented science behind ETs, farmers have questioned the adoption and reliability in a search for higher production, highlighting the importance of reviewing this topic. Thus, based on the available literature, the role of ETs in optimizing insecticide application in soybean production around the world is herein discussed, highlighting the importance of their adoption to mitigate the overuse of chemicals by emphasizing examples from the major world soybean producers (Brazil, the United States of America, Argentina, and China). In conclusion, this review highlights the importance of changing farmers’ perception that using more insecticide is necessary to guarantee higher yields. On the contrary, only by the adoption of ETs within Integrated Pest Management is it possible to obtain better pest management and, consequently, reduce yield loss. Despite some limitations related to their simplicity and risks of adoption, the use of ETs improves soybean sustainability and farmers’ profits while benefiting the agroecosystem. For future directions, their complexity should increase to more realistically represent agroecosystems; in addition, tools should be developed (computer programs and smartphone apps using, for instance, artificial intelligence) to translate this complexity into easy-to-adopt ETs.

Agrochemicals doi: 10.3390/agrochemicals5020022

Authors: Everaldo Attard Jules Siedenburg

Alkaloids are structurally diverse, nitrogen-containing plant secondary metabolites with well-documented insecticidal activity. This review examines alkaloid-based insecticides, focusing on their chemical diversity, biosynthetic origins, plant distribution, and physicochemical properties relevant to pest control on farms. The principal molecular targets and modes of action are discussed, including interactions with nicotinic acetylcholine receptors, acetylcholinesterase, ryanodine receptors, and GABAergic signaling. Another focus is key metabolic enzymes, together with their activity spectra against major agricultural pests. Recent advances in rational structural modification, supported by crystallographic data, computational modeling, and structure–activity relationship studies, are highlighted as strategies to enhance the potency, selectivity, and stability of these compounds. Toxicological profiles, food residue behavior, analytical challenges, and regulatory considerations are critically assessed, emphasizing that natural origin does not equate to inherent safety. The review further evaluates the role of alkaloid-based insecticides within integrated pest management systems and identifies key research gaps related to environmental safety, non-target effects, and regulatory development and harmonization. It concludes that alkaloids are positioned as potentially valuable tools for sustainable agriculture when deployed within science-based regulatory frameworks and integrated control strategies.

Agrochemicals doi: 10.3390/agrochemicals5020021

Authors: Renu Munjal Yashika Bhatia Vineeta Rana

The growing demand for food production has increased the pressure on soil and fertilizer use, often leading to nutrient losses, soil degradation, and environmental pollution. Green chemistry offers practical solutions to these challenges by encouraging cleaner, safer, and more efficient ways of producing and using fertilizers. This review summarizes recent advances in multi-nutrient sustainable fertilizers developed through green chemistry principles, including renewable raw materials, low-toxicity synthesis methods, and environmentally friendly delivery systems. Different approaches, such as controlled-release carriers, nano-enabled formulations, chelated nutrients, and bio-based coatings, are discussed with a focus on how they reduce nutrient losses and improve soil and plant health. The review also highlights the benefits and limitations of these technologies, gaps in current research, and the need for long-term field studies to assess their safety and effectiveness. Overall, green chemistry-guided fertilizer development shows strong potential to support sustainable agriculture by improving nutrient efficiency while reducing environmental impacts.

Agrochemicals doi: 10.3390/agrochemicals5020020

Authors: Hyeong-Wook Jo Joon-Seok Lee Il Jang Young-Il Cho Joon-Kwan Moon

This study investigates the decomposition kinetics and microplastic residue formation of the polymer-coated controlled-release fertilizers (CRFs) LN40 and Eco-LN40 under simulated photodegradation conditions. Eco-LN40, containing TiO2 as a photocatalyst, achieved complete decomposition (100 ± 2%) after 60 days of xenon-arc irradiation (p < 0.05), whereas LN40 achieved only 14–31% decomposition. Analytical characterization using TED-GC/MS, FTIR, and Raman spectroscopy confirmed that polyethylene (PE) signals completely disappeared in Eco-LN40 but persisted in LN40, indicating that microplastics did not form and that there was total oxidation into CO2 and H2O. SEM–EDS revealed Ti enrichment and surface fragmentation consistent with photoinduced radical oxidation. This study provides qualitative and mechanistic evidence that TiO-catalyzed photodegradation can eliminate polymer residues, mitigate the risk of microplastic contamination in agricultural soils, and support carbon-neutral fertilizer technologies.

Agrochemicals doi: 10.3390/agrochemicals5020019

Authors: Rafael Manuel de Jesús Mex-Álvarez María Magali Guillen-Morales David Yanez-Nava Patricia Margarita Garma-Quen Fernando Gaspar Ortiz-Ballina Roger Enrique Chan Martínez

Pharmaceuticals are increasingly recognized as emerging contaminants with potential impacts on agroecosystems. Among these, antibiotics such as ciprofloxacin (CPX) persist in wastewater and may enter agricultural soils through irrigation or fertilization practices, yet their effects on crop plants remain poorly understood. This study evaluated the phytotoxic effects of ciprofloxacin on early growth and photosynthetic pigment content in purple maize (Zea mays L.), a variety of nutritional and cultural importance. Seeds were germinated in an agar-based medium (0.5%) and exposed to three concentrations of ciprofloxacin (3, 10, and 30 mg·L−1) for seven days under controlled conditions. Germination percentage, seedling fresh weight, organ length (root, stem, and leaf), and photosynthetic pigment concentrations (chlorophylls a and b, and carotenoids) were determined. Ciprofloxacin exposure resulted in dose-dependent reductions in germination (from 83% at 3 mg·L−1 to 50% at 30 mg·L−1) and root elongation, while stem length remained unaffected. Chlorophyll content decreased with increasing ciprofloxacin concentration, with the lowest values observed at 30 mg·L−1, while carotenoid levels remained stable, with no statistically significant differences observed. Although ciprofloxacin is typically detected in environmental matrices at ng–µg L−1 levels, higher concentrations may occur in localized contamination hotspots; ciprofloxacin affected early developmental and physiological processes in maize under these elevated exposure conditions. These findings highlight the importance of integrating phytotoxicity assessments into agricultural ecopharmacovigilance strategies and contribute to understanding the risks associated with pharmaceutical contamination in crop production systems.

Agrochemicals doi: 10.3390/agrochemicals5020018

Authors: Emilee Storfie Sheau-Fang Hwang Stephen Strelkov

Salicylic acid (SA) is a key regulator of plant immunity and contributes to defence against Plasmodiophora brassicae, the causal agent of clubroot disease in canola (Brassica napus) and other crucifers. Exogenous SA applications have reduced clubroot severity in some Brassica pathosystems, yet the effectiveness of foliar SA treatment against the predominant resistance-breaking pathotype 3A in western Canada remains unclear. This study evaluated the effects of weekly foliar applications of 0, 1, 5, or 10 mM SA on clubroot development in two B. napus var. napobrassica cultivars under greenhouse and growth chamber conditions. Plants inoculated with pathotype 3A were assessed for disease severity, pathogen resting spore load, plant height, and transcript accumulation of SA-responsive genes. Overall, SA treatments resulted in modest reductions in disease severity and resting spore concentrations; however, treatment effects did not reach statistical significance in most cases. Collectively, foliar SA applications provided limited suppression of clubroot caused by pathotype 3A. Further optimization of SA concentration, timing, and delivery, particularly when targeting the root zone, may be required before SA can be considered a complementary tool in integrated clubroot management.

Agrochemicals doi: 10.3390/agrochemicals5020017

Authors: Yair Palma-Rosas Nubia Guadalupe Torres-Beltran Ramona Pérez-Leal Laura Raquel Orozco-Melendez Omar Castor Ponce-García Juan Manuel Soto-Parra

In Mexico, pecan (Caria illinoienensis Wangenh K. Koch) cultivation is considered a primary agricultural activity of great importance, particularly in the state of Chihuahua. Due to the region’s climatic conditions, the soils used for this crop present several limitations that may restrict their agricultural use, as they often exhibit low or null fertility, classifying them as marginal soils. However, these soils can be rehabilitated through appropriate management practices. Among the main recovery strategies are the application of mineral and organic amendments and the use of plant-growth-promoting microorganisms, all of which are considered environmentally friendly alternatives. Therefore, the objective of this study was to identify the types of mineral and organic amendments suitable for the recovery of marginal soils in the agronomic management of pecan cultivation. This study was conducted in the San Cristóbal pecan orchard, located in the municipality of Jiménez, Chihuahua, using a 56 factorial design, reduced to 25 treatments through the Taguchi L25 method. Statistical analysis was performed using response surface methodology, and the evaluated parameters included basic, physical, fertility, and cation-exchange properties of the soil. The results showed that zeolite (19.30 t ha−1) and calcium carbonate (12.70 t ha−1) were amendments that produced the greatest effect on the evaluated parameters. The use of these amendments can significantly complement annual fertilization programs, contributing to meeting the crop’s nutritional demands under a sustainable management approach for pecan production.

Agrochemicals doi: 10.3390/agrochemicals5020016

Authors: Mariana Cristina Barbosa Bhim Bahadur Ghaley Bruno Horschut Lima Thiago Assis Rodrigues Nogueira William Cesar Nishimoto Ito Loiane Fernanda Romão de Souza Guilherme Carlos Fernandes Karina da Silva Souza Edson Cabral da Silva Carlos Eduardo da Silva Oliveira Marcelo Carvalho Minhoto Teixeira Filho

Silicate rocks represent alternative K sources when finely ground, reducing production costs and dependence on imported fertilizers. Therefore, this study aimed to evaluate the effects of potassium (K) dose, application timing, and fertilizer sources on the concentrations and accumulation of K, silicon (Si), and sodium (Na) in maize diagnostic leaves, straw, and grains under a no-tillage system in Savanna. The soil was classified as Typic Haplustox (Oxisol). The experiment followed a randomized block design in a 2 × 4 × 3 factorial scheme, with two application times (30 days before sowing soybean and at sowing soybean), four K2O rates (0, 40, 80, and 120 kg ha−1), and three sources (KCl, Potasil, and Ekosil). K fertilization was applied by broadcasting without incorporation, before the preceding crop. Potasil provided a higher foliar Si concentration, and Si accumulation in grain and straw increased with the increment of K fertilization using the Potasil. Early fertilization promoted greater K accumulation in maize straw. For grain K accumulation, moderate K2O doses favor greater accumulation, with Ekosil and Potasil showing superior results compared to KCl. There was less sodium accumulation in the grains with Ekosil compared to KCl. Agronomic efficiency is maximized at 40 kg ha−1 of K2O, with Ekosil showing the best performance for maize crop. These findings indicate that alternative K sources, applied at optimized rates, improve crop nutrition and promote sustainability in soybean–maize crop rotation.

Agrochemicals doi: 10.3390/agrochemicals5020015

Authors: Ikponmwosa Egbon Andrei Alyokhin

Vernonia amygdalina Delile (Asteraceae), commonly known as bitter leaf, is a tropical shrub that may potentially serve as a biopesticide against the Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), a key pest of potatoes. The beetle’s behavioral response to the methanolic leaf extract of V. amygdalina was evaluated in this study. Using no-choice, dual-choice, and wind-tunnel assays under laboratory conditions, we evaluated responses of larvae and adults to potato leaf discs treated with V. amygdalina extract in a randomized complete block design, measuring feeding behavior, leaf damage levels, and remaining leaf area. The results showed that V. amygdalina had no biocidal effects against the beetle, as no mortality was incurred. However, dose-linked antifeedant effects were evident in both no-choice and dual-choice arenas. Vernonia amygdalina minimized leaf-area loss most effectively at the highest concentration, especially against the larvae. The extract showed no olfactory repellency but acted as an antifeedant, possibly through contact or taste (gustatory) receptors. The consistent behavioral avoidance at higher concentrations suggests that V. amygdalina acts as a form of deterrent against the Colorado potato beetle.

Agrochemicals doi: 10.3390/agrochemicals5010014

Authors: Domenico Prisa Aristidis Matsoukis Aftab Jamal Damiano Spagnuolo

Plant growth regulators (PGRs) are extensively used in modern agriculture to modify plant developmental processes, enhance productivity, and improve crop quality under increasingly variable environmental conditions. While their agronomic benefits are well established, growing attention has been directed toward understanding their broader environmental implications. In this current review, we analyze recent research published over the last five years to evaluate the environmental behavior and ecological impacts of widely used natural and synthetic plant growth regulators. Particular emphasis is placed on their persistence and mobility in soil and water, their interactions with soil microbial communities, and their effects on non-target terrestrial and aquatic organisms. Recent advances in analytical detection and ecotoxicological assessment have revealed that several PGRs, despite being applied at low doses, may exhibit prolonged environmental residence and subtle biological effects, particularly following repeated applications. Alterations in soil enzyme activity, shifts in microbial community structure, and growth disturbances in non-target plants and aquatic primary producers have been increasingly reported. The review also discusses emerging strategies aimed at reducing environmental risks, including precision application technologies, the development of biodegradable regulators, and improved regulatory frameworks. Overall, these findings highlight the need for integrated risk assessment approaches and long-term field studies to support the sustainable use of plant growth regulators in agroecosystems.

Agrochemicals doi: 10.3390/agrochemicals5010013

Authors: Gabriel da Silva Medina Fernando Augusto da Silveira Elis Marina de Freitas Vitor Hugo Souza Resende Éder de Souza Martins

Farmers worldwide use agrochemicals and biological inputs to fertilize fields, manage pests and diseases, and promote plant growth. However, there is still limited field-based evidence on the extent to which biological inputs function as substitutes, incremental complements, or alternatives to agrochemicals in key farming practices. This study presents preliminary results on the use of synthetic and biological inputs for the most common practices employed by large soybean farmers in central Brazil. We combined literature review, regulatory data on registered biological products, and in-person interviews with farmers and market experts. Our results show that, in most practices, biological products are adopted alongside the continued use of synthetic inputs, in some cases reducing the frequency or dosage of chemical applications. Inoculants based on nitrogen-fixing bacteria already substitute mineral nitrogen fertilization in soybean, while biosolubilizers and plant activators are used incrementally to enhance the efficiency of chemical fertilizers. Bioinsecticides and biofungicides are predominantly employed as alternatives within spray programs, especially in preventive or early interventions, thereby reducing the number of conventional pesticide sprays. Bionematicides emerge as the main biological tools used as substitutes for synthetic nematicides in preventive treatments, whereas biological herbicides are not yet available on the market. Field evidence presented in this study showed that farmers adopt biological products in diverse ways, including as substitutes, incremental, or alternatives to chemical products, depending on the technologies available. These findings provide a more nuanced understanding than the common views that, on one hand, biological inputs simply complement rather than substitute chemical products, and on the other, that biological solutions can fully substitute synthetic products. As environmental and economic implications, we conclude that biological inputs can underpin trajectories towards more regenerative management in large-scale soybean systems, even when synthetic inputs remain part of the production matrix.

Agrochemicals doi: 10.3390/agrochemicals5010012

Authors: Adriana Morfín-Gutiérrez Josué I. García-López Patricia A. de León-Martínez Norma A. Ruiz-Torres Agustín Hernández-Juárez Perpetuo Álvarez-Vázquez Antonio Flores-Naveda

Zinc (Zn) is a mineral that plays a vital role in the growth and development processes of different plants. Although it is required in small quantities, its presence is essential in a crop. In recent years, zinc oxide nanoparticles (ZnO NPs) have garnered significant interest in agriculture due to their unique physical and chemical properties. As a result, they can be used as alternative fertilizers to help crops experiencing mineral deficiency, stress, or fungal problems. These nanomaterials can be obtained through various synthesis methods, including sol–gel, chemical precipitation, microemulsion, and green synthesis, among others. This enables managing their size, shape, and internal arrangement, establishing their ultimate characteristics and feasible uses. In this review, we will present some of the most commonly used synthesis methods for obtaining ZnO NPs, the frequently used characterization techniques, as well as some of the positive and toxic effects caused by their application in crops.

Agrochemicals doi: 10.3390/agrochemicals5010011

Authors: Deniz Inci Kassim Al-Khatib

Florpyrauxifen-benzyl (FPB) is an auxin-mimic herbicide that controls selected grasses, sedges, and broadleaves in rice cropping systems. Field experiments were conducted in 2023 and 2024 to characterize the effects of FPB on crop safety and weed control when applied alone or in combination with other herbicides, and to assess whether FPB can provide season-long, effective weed management. Base treatments of benzobicyclon (BBC)/halosulfuron-methyl (HSM), clomazone (CLM), or thiobencarb (TBC) were applied on the day of seeding (DOS) or within the 2-leaf stage (LS) rice and followed by foliar treatments of FPB alone or in a mixture with bispyribac-sodium (BPS), penoxsulam (PNX)/cyhalofop-butyl (CHB), or propanil (PPL). Additionally, FPB was applied alone with no prior base treatment, in combination with a mixture partner, and as a sequential treatment, 14 days apart, with the first application made to 4- to 5-LS rice; in contrast, the second application was made to mid-tillering rice. The FPB applied alone or in sequential application showed results for more than 98% of watergrasses and 100% of ricefield bulrush, smallflower umbrella sedge, ducksalad, redstems, and all other broadleaves control at 56 days after treatment (DAT). When applied after the base treatments, the weed control increased to 100% for all weed species at 14 DAT. The sequential application of FPB achieved the highest yields of 7683 kg ha−1 in 2023 and 11,249 kg ha−1 in 2024, resulting in 3.6- and 6.4-fold increases in rice yield over the nontreated control. Owing to its excellent sedge and broadleaf weed control and good activity on troublesome grasses, such as barnyardgrass, FPB could be an essential part of the weed management programs in rice production systems.

Agrochemicals doi: 10.3390/agrochemicals5010010

Authors: Ioannis Vagelas

The foliar pathogens of wheat, particularly Zymoseptoria tritici and Pyrenophora tritici-repentis, represent a significant threat to yield. We used a SEIR (Susceptible–Exposed–Infected–Removed) model to quantify epidemic dynamics based on different fungicide application strategies, focusing on the daily dynamic growth rate r(t) (net infection increase) and the removal rate γ(t) (loss infectious tissue) after BBCH 37. In Scenario A (treatment of seed with Systiva®), the r(t) of Z. tritici was positive only during the early phase of the epidemic, followed by progressive suppression over time, while the r(t) for P. tritici-repentis remained negative throughout. Scenario B (seed treatment combined with foliar propiconazole) resulted in uniformly negative r(t) values for both pathogens, indicating stronger and sustained suppression. These findings highlight the practical utility of epidemic growth rate modeling for evaluating fungicide strategies and support integrated seed + foliar applications as a robust approach to disease management in wheat.

Agrochemicals doi: 10.3390/agrochemicals5010009

Authors: Yuzhe Du Shane Scheibener Nathan S. Little Blake H. Elkins Yu-Cheng Zhu

Field-evolved resistance of Helicoverpa zea to crops expressing Cry insecticidal proteins from Bacillus thuringiensis (Bt) is widespread across the United States. To comparatively evaluate physiological factors associated with Bt susceptibility, we analyzed two laboratory strains (Benzon and SIMRU) and one field colony obtained from a commercial corn field near Pickens, Arkansas. Biochemical assays of larval midgut extracts showed that Pickens exhibited significantly altered activities of chymotrypsin-like proteases, aminopeptidase N (APN), and alkaline phosphatase (ALP) compared with the SIMRU or Benzon colonies, with differences varying by larval instar. In contrast, trypsin-like protease activities did not differ significantly among the three colonies. Gene expression analyses of ten serine protease genes and seven candidate Cry receptor genes (including cadherin, ATP-binding cassette family C2, ALP, and four APN genes) revealed significant transcriptional differences in the Pickens relative to the lab colonies. Collectively, these results suggest that chymotrypsin-like proteases may play an important role in the activation of Cry toxins in H. zea. Altered chymotrypsin and APN activities, together with differential gene expressions in the Pickens population, likely contribute to reduced Bt susceptibility. The biochemical and molecular differences provide insight into potential physiological factors underlying reduced Bt susceptibility and may inform future Bt resistance monitoring and management strategies.

Agrochemicals doi: 10.3390/agrochemicals5010008

Authors: Gabriel N. Araújo Luis O. Viteri Jumbo Pedro B. Silva Leonardo B. Souza Anielle C. A. Silva Lucas Anhezini Gil. R. Santos Raimundo W. S. Aguiar Eugênio E. Oliveira Jerusa M. Oliveira

Drosophila suzukii (Diptera) is a polyphagous fly responsible for a huge loss in production of thin-skinned berries, usually controlled with low-selective synthetic pesticides, which can be toxic for biodiversity and human health. Biorational control of D. suzukii is challenging, despite many known lethal compounds, since most experiments happen in laboratory conditions, and agroecosystems include complex biotic and abiotic variables. Nanoencapsulation rises as an efficient alternative for optimizing pesticide development by protecting active ingredients and increasing selectivity. This review aimed to gather recent (over the last 5 years) research about plant-derived insecticides with the potential to control D. suzukii, examining their toxicity mechanisms and exposure methods, and to identify research gaps and perspectives, especially for nanoproducts. These efforts resulted in the selection of 31 articles, evaluating lethality and behavioral modulation caused by plant-based compounds, which exerted mainly attraction, repellency, and oviposition deterrence. Most studies were carried out under laboratory conditions, mostly testing plants from the Lamiaceae and Asteraceae botanical families, indicating essential oils as potential short-life pesticides against every life stage of D. suzukii, although their physicochemical instability limits field application. There are few studies addressing nano-pesticides for controlling D. suzukii, and these data contribute to botanical prospection for pesticide compounds and point to the development of plant-based nano-pesticides for controlling D. suzukii as a research gap with potential to enable field trials.

Agrochemicals doi: 10.3390/agrochemicals5010007

Authors: Luis A. Valdivia-Chávez Aranzy J. Flores-Leos Carlos H. López-Lariz Juan Ibarra-Hernández Bruno A. Marichal-Cancino Jesús Chávez-Reyes

The fungicide Imazalil (IMZ) is widely used to maintain the freshness of fruits and vegetables after harvest. Despite its widespread use, the neurotoxic effects of IMZ remain poorly studied. Thus, in this work, we aimed to investigate the effects of subacute IMZ exposure on memory and learning, as well as on cholinesterase (ChE) activity, in orally exposed rats. To do so, Wistar rats were exposed to doses corresponding to 1/8, 1/4, and 1/2 of the LD50 of IMZ. Each dose was divided into four equal parts and administered once daily for four consecutive days, while behavioral performance was assessed using the Barnes Maze. On day 5, we measured ChE activity in the hippocampus and serum. The enzymatic activity assays demonstrated a dose-dependent decrease in both cholinesterase activities at 1/4 LD50 of IMZ. In addition, rats in the control group exhibited a typical learning curve in the Barnes maze, characterized by reduced latency and fewer attempts to locate the escape box from the first session (S1) to the final session (S4). The typical learning curve was prevented by a 1/4 LD50 treatment. Additionally, this dose prevented an increase in spatial navigation strategy use, observed in the control group (S1 vs. S4). To our knowledge, these results proved that IMZ inhibits in vivo the activity of both brain and serum ChEs, and exhibits evidence of learning and memory impairments, suggesting that IMZ has neurotoxic effects in rats, probably mediated by alterations in the cholinergic system.

Agrochemicals doi: 10.3390/agrochemicals5010006

Authors: Mulinganya Noel Nabahungu Nsharwasi Léon Faki Oyédekpo Chabi Ahanchede Adam Kouélo-Alladassi Felix Adeniyi Gideon Masimane Jules Cirhuza Jackson Mirali Bashagaluke Janvier Dagbenonbakin Gustave Aliou Saïdou

Maize is vital for food systems and rural livelihoods in the Democratic Republic of Congo (DRC). Continuous cultivation depletes soil nutrients, reducing maize production. Inorganic (or mineral) fertilizers provide nutrients rapidly, but their cost and sustainability concerns have prompted interest in alternatives. Biological amendments improve nutrient uptake and soil structure and boost crop resistance, potentially cutting mineral fertilizer use. The present study aims to investigate the direct and residual effects of biological amendments (BAs) on maize productivity in the Eastern DRC, both when applied alone or combined with inorganic fertilizer, with trials conducted in the Kabare, Kalehe, and Ruzizi Plain regions from October 2022 to June 2024. Two trials across four seasons gathered data using a randomized complete block design (RCBD) with nine treatments and three replicates: Control, without fertilizer application; farmer practice; inorganic fertilizer (NPK 17-17-17 and urea); BA_1: Lactobacillus; BA_2: fish serum; BA_3: black soldier fly (BSF) compost; BA_1 + inorganic fertilizer; BA_2 + inorganic fertilizer; and BA_3 + inorganic fertilizer. The results identified three categories: integrated organic and inorganic fertilizers, single applications, and inconsistent uses. The best outcomes emerged from treatments combining Lactobacillus, fish serum, and BSF compost with inorganic fertilizer, positively impacting maize yield parameters. The study confirms that combining biological amendments and mineral fertilizers significantly (p < 0.001) enhances maize productivity in the Eastern DRC. Performance differences across locations emphasize the influence of local soil characteristics and targeted nutrient strategies.

Agrochemicals doi: 10.3390/agrochemicals5010005

Authors: Yan Lucas Leite Elizângela Aparecida dos Santos

This study provides a comprehensive long-term assessment of dithiocarbamate (DTC) fungicide residues in foods consumed in Brazil, analyzing nearly two decades of official monitoring data from the Pesticide Residue Analysis Program (PARA/ANVISA) from 2001 to 2023. By integrating fragmented annual reports into a single temporal framework, this study offers a novel evaluation of detection frequencies, residue levels, and regulatory compliance over time. Of the 21,274 samples analyzed, 23.90% contained residues of these fungicides. Papaya showed the highest detection frequency (92.59%) in 2005, while apple showed the highest average percentage of detections (51.68%). Lettuce showed the highest residual levels (10.05 mg kg−1) in samples from the 2017–2018 cycle, despite the lack of authorization for the use of these products in this crop. Strawberries and carrots showed concentrations above the maximum residue limit (MRL), with excesses. Residues of unauthorized pesticides were also detected in crops such as guava, pineapple, and sweet potato. Temporal correlations between detections and residues indicated significant variations among the foods evaluated, with potatoes, strawberries, and lettuce showing the highest residual levels. An overall declining trend in detections and residue concentrations was observed throughout the analyzed period, potentially reflecting improvements in regulatory oversight, agricultural practices, and analytical sensitivity over time. From a public health perspective, the persistence of elevated residues and unauthorized uses highlights the need for continuous surveillance, strengthened enforcement, and risk communication strategies to ensure food safety and consumer protection.

Agrochemicals doi: 10.3390/agrochemicals5010004

Authors: Mohamed Ou-Zine Said El Kinany Said Ezrari Rachid Bouamri

The one health approach recognizes the interconnection between human, animal, and environmental health, emphasizing that human health should never be threatened in the pursuit of agricultural productivity. Indeed, within agricultural systems, this approach is particularly relevant, as the overuse of chemical inputs and the mismanagement of organic wastes can directly threaten human health. Overuse of chemical inputs can result in various health disturbances and contribute to the development of acute or chronic human diseases. Likewise, organic wastes constitute potential human health risks due to the presence of pathogens in these wastes such as bacteria, viruses, fungi, and parasites. Despite increasing research, many studies often lack integrated risk assessments of agrochemicals and organic waste within a “One Health” framework, leaving gaps in practical guidance for safe agricultural management. This review was conducted to address these gaps and answer the following questions: What are the human health risks associated with agrochemicals and mismanaged organic wastes? How can composting/compost mitigate these risks and support sustainable agricultural production? It examines the role of composting in managing organic wastes, producing high-quality compost, and reducing exposure to hazardous chemicals and pathogens. Furthermore, it outlines key characteristics of compost required to ensure safety for humans, plants, soil, and ecosystems. By integrating evidence on human health and crop productivity, this review provides insights for safe, sustainable agricultural practices within a unified One Health framework.

Agrochemicals doi: 10.3390/agrochemicals5010003

Authors: Isabela de Carvalho Contesoto Ana Paula Boromelo Ana Paula da Silva Mendonça Cinthia Martins Corbetta Amanda Castro Comar Marco Aurélio Schüler de Oliveira Larissa Fonseca Tomazini João Henrique Vieira de Almeida Junior Marcelo Augusto Batista Paulo Sérgio Alves Bueno Caroline Barbeiro Ana Paula Ferro Wanderley Dantas dos Santos Rodrigo Polimeni Constantin Osvaldo Ferrarese-Filho Rogério Marchiosi

Enzymes of the sulfur assimilation pathway represent promising candidates for selective herbicide development. This study investigated the effects of O-benzyl-serine (OBS), a newly identified inhibitor of O-acetylserine(thiol)-lyase (OAS-TL), on two C3 weed species, Ipomoea grandifolia and Euphorbia heterophylla. Plants were cultivated hydroponically for 12 days in the presence of OBS (0–500 µM). OBS inhibited root growth in both species in a dose-dependent manner, with I. grandifolia being more sensitive. OAS-TL activity decreased in the roots of I. grandifolia but increased in the leaves of E. heterophylla. Nutrient profiling revealed significant alterations in sulfur, magnesium, and calcium contents, associated with chlorosis and reduced root and leaf development. While photosynthetic performance appeared unaffected at the lowest OBS concentration tested (62.5 µM), higher doses drastically reduced leaf expansion, preventing further measurements. Given this marked decline in foliar development, it is reasonable to infer that the overall photosynthetic capacity of the plants was also negatively affected under severe OBS exposure. OBS also disrupted apical dominance, promoting lateral shoot formation. These findings demonstrate that OBS differentially affects sulfur metabolism and growth in a species- and organ-specific manner, supporting its potential as a prototype molecule for herbicides targeting novel biochemical pathways.

Agrochemicals doi: 10.3390/agrochemicals5010002

Authors: Amanda do Carmo Alves Ana Carolina Silva Adriane Toledo da Silva Nivia Kelly Lima Sales Ruth Celestina Condori Mamani Lisseth Bibiana Puentes Figueroa Elias Honorato Gomes Debora Castro Toledo de Souza Rosangela Cristina Marucci Filippe Elias de Freitas Soares

The use of proteolytic enzymes in association with entomopathogenic fungi offers a promising alternative for improving the biological control of insect pests. This study evaluated the compatibility between Beauveria bassiana and papain and the effectiveness of their combined application in controlling Tenebrio molitor. Conidial viability in the presence of papain was monitored for 48 h and showed a reduction in germination from 100% to approximately 70%, without detrimental effects on fungal performance. Papain activity remained stable up to 12 h, declining afterward, indicating biochemical compatibility. Bioassays revealed significant differences among treatments (p < 0.01). In larvae, mortality ranged from 5.18 ± 0.19% in the control to 49.62 ± 2.00% with papain, 62.24 ± 0.58% with conidia, and 89.71 ± 1.06% in the combined treatment; papain and conidia alone did not differ statistically. In pupae, mortality reached 2.20 ± 0.00% in the control, 47.38 ± 0.69% with papain, 63.69 ± 0.69% with conidia, and 85.91 ± 0.84% with the combination, with all treatments differing significantly. Fungal reisolation confirmed typical B. bassiana development. Overall, the results show that papain does not compromise fungal viability and that its combination with B. bassiana enhances entomopathogenic activity, supporting its potential for integrated pest management.

Agrochemicals doi: 10.3390/agrochemicals5010001

Authors: Fares Howari

Uniform application of fertilizers and pesticides continues to dominate global agriculture despite significant spatial variability in soil and crop conditions. This mismatch results in avoidable yield gaps, excessive chemical waste, and environmental pressures, including nutrient leaching and greenhouse gas emissions. The integration of Artificial Intelligence (AI) and Remote Sensing (RS) has emerged as a transformative framework for diagnosing this variability and enabling site-specific, climate-responsive management. This systematic synthesis reviews evidence from 2000–2025 to assess how AI–RS technologies optimize agrochemical efficiency. A comprehensive search across Scopus, Web of Science, IEEE Xplore, ScienceDirect, and Google Scholar were used. Following rigorous screening and quality assessment, 142 studies were selected for detailed analysis. Data extraction focused on sensor platforms (Landsat-8/9, Sentinel-1/2, UAVs), AI approaches (Random Forests, CNNs, Physics-Informed Neural Networks), and operational outcomes. The synthesized data demonstrate that AI–RS systems can predict critical soil attributes, specifically salinity, moisture, and nutrient levels, with 80–97% accuracy in some cases, depending on spectral resolution and algorithm choice. Operational implementations of Variable-Rate Application (VRA) guided by these predictive maps resulted in fertilizer reductions of 15–30%, pesticide use reductions of 20–40%, and improvements in water-use efficiency of 25–40%. In fields with high soil heterogeneity, these precision strategies delivered yield gains of 8–15%. AI–RS technologies have matured from experimental methods into robust tools capable of shifting agrochemical science from reactive, uniform practices to predictive, precise strategies. However, widespread adoption is currently limited by challenges in data standardization, model transferability, and regulatory alignment. Future progress requires the development of interoperable data infrastructures, digital soil twins, and multi-sensor fusion pipelines to position these technologies as central pillars of sustainable agricultural intensification.

Agrochemicals doi: 10.3390/agrochemicals4040023

Authors: Bruna Pereira Almeida Luiz Felipe Silveira Pavão Marcelo Silveira de Farias Nidgia Maria Nicolodi Mirta Teresinha Petry Marisa Menezes Leal Paulo Carteri Coradi Victória Lumertz de Souza Mayara de Souza Queirós Guilherme de Figueiredo Furtado Marcus Vinicíus Tres Giovani Leone Zabot

This systematic review aimed to examine recent advances (2021–2025) in the conversion of agricultural biomass into biomaterials, biofertilizers, and bioproducts. Studies were included when addressing biomass types, pretreatment methods, conversion technologies, or resulting applications. Non-agricultural biomass, non-original research, and works outside the defined timeframe were excluded. Literature was identified in Scopus and Web of Science, complemented by Espacenet, Google Scholar, and institutional databases (USDA, FAO, IRRI, ABARES, UNICA, and CONAB, among others), totaling 108 documents referenced in this work. Risk of bias was minimized through predefined eligibility criteria and full-text assessment. Results were narratively synthesized, supported by figures and tables highlighting technological trends. Studies involving a wide range of agricultural biomasses (e.g., rice straw, corn stover, wheat straw, and sugarcane bagasse) were evaluated. Main outcomes included the development of bioplastics, biofoams, composites, hydrogels, bioceramics, biochar-based fertilizers, organic acids, enzymes, and green solvents. Evidence consistently indicated that pretreatment strongly influences conversion efficiency and that enzymatic and thermochemical routes show the highest potential for integrated biorefineries. Limitations included heterogeneity in biomass composition, variability in methodological quality, and scarcity of large-scale studies. Overall, findings underscore agricultural biomass as a strategic feedstock for circular bioeconomy models, with implications for sustainable materials, renewable energy, and low-carbon agriculture. Continued innovation, supportive policies, and improved logistics are essential for scaling biomass-based technologies.

Agrochemicals doi: 10.3390/agrochemicals4040022

Authors: Jishnu K. S. Krishnan John R. Moffett Aryan M. Namboodiri

Organophosphate (OP) insecticide poisoning remains a significant world health issue. Despite attempts to reduce OP insecticide use in some countries, they continue to be used extensively in many regions, putting agricultural workers at risk of excess exposure. Furthermore, the high toxicity and ready availability of OP insecticides in agricultural settings have created an additional public health issue due to their use in attempted suicides. Tens of thousands of people are admitted to hospitals every year after intentional ingestion of OP insecticides. The standard treatment regimen for OP poisoning can prevent mortality, even in some severe cases, but these treatments do not protect the central nervous system (CNS) from excitotoxic damage, and therefore, additional neuroprotective treatments are needed. One promising treatment is the use of halogenated ether anesthetics, including isoflurane, a common anesthetic available in hospitals throughout the world. Isoflurane can be administered by inhalation using vaporizer equipment, or it can be injected intravenously as a lipid–water emulsion. In both cases, excellent neuroprotection has been observed in preclinical models, even when administered up to 1 h after the onset of OP insecticide poisoning. Prolonged administration was not necessary for neuroprotective efficacy, with administration times of only 5 min being sufficient. Including inhalational anesthetics as an adjunct to the standard treatment for OP poisoning could significantly reduce chronic morbidities, especially long-term CNS damage. Research is ongoing to bring this promising treatment to human trials.

Agrochemicals doi: 10.3390/agrochemicals4040021

Authors: Peter Martin Chilipweli Elias C. Nyanza Aiwerasia Vera Ngowi

Background: The use of pesticides among smallholder farmers, agrochemical sellers, and agricultural officers involves a complex interplay of knowledge, economic factors, and regulatory frameworks. Therefore, this study explores the patterns, practices, and socio-environmental dynamics of pesticide use among smallholder farmers and agro-input sellers in Iringa and Njombe. Method: This study employed a qualitative, phenomenological design, guided by the socio-ecological model (SEM), to explore the lived experience of farmers, agro-dealers, and extension officers. It involved a total of 23 interviews performed in the Njombe and Iringa regions. Data were collected between October 2024 and March 2025, using a combination of in-depth phenomenological interviews, key informant interviews, and field observations, and were categorized into themes and subthemes analyzed using InVivo. Results: The study involved a total of 23 participants drawn from the Iringa and Njombe regions. The gender distribution was nearly balanced, with 52.1% male and 47.8% female respondents. The mean age of participants was 33 years (95% CI: 29.3–37.3). In terms of education, over half (52.17%) had completed primary school. The findings show that smallholders in Iringa and Njombe widely use mixed pesticides and fertilizers, rely on trusted brands, and adapt to climate impacts, but face challenges with regard to unsafe mixing, poor storage, fake products, and weak regulation, highlighting the need for better education, market oversight, and safer practices. Conclusion: Using the socio-ecological model, the findings indicate that pesticide use among smallholder horticultural farmers in Iringa and Njombe is influenced by a complex interaction of socio-economic constraints, market forces, climate variability, and institutional shortcomings. Although farmers have some awareness of safe practices, systemic barriers continue to limit the adoption of sustainable pesticide management.

Agrochemicals doi: 10.3390/agrochemicals4040020

Authors: Christian Silva-Sanzana Plinio Innocenzi Luca Malfatti Federico Fiori Francisca Blanco-Herrera Juan Hormazabal María Victoria Gangas Oscar Diaz Iván Balic

Carbon dots (CDs) are promising for agro-environmental applications; however, clear connections between synthesis, photophysical properties, size, and biosafety are often not well established. In this study, we map these relationships for glucose–arginine CDs (GA-CDs). By using microwave and hydrothermal routes at precursor ratios of 1:3, 1:9, and 1:15, we produced sub-10 nm nanoparticles (analyzed by dynamic light scattering and atomic force microscopy) that exhibit tunable absorption and emission properties, as well as surface properties (demonstrated through UV–Vis spectroscopy, 3D photoluminescence, and FTIR analysis). The hydrothermal 1:9 condition yielded the narrowest size distribution and red-shifted photoluminescence. Across biological models spanning plants, insects, plant-growth-promoting bacteria (PGPR), and human cells, GA-CDs were well tolerated, with no adverse changes detected in plant stress markers, aphid feeding behavior or fecundity, or PGPR growth. In A549 cells, viability remained stable up to a concentration of 0.125 mg mL−1, while exposure to 0.5 mg mL−1 reduced viability, establishing a practical operating range. These results provide a clearer picture of how the structure and properties of carbon dots derived from arginine and glucose are correlated to their safety. The GA-CDs are, therefore, useful, and traceable tools for agro-environmental research. The findings support their use as biocompatible nanomaterials for studying interactions among plants, insects, and microbes in agriculture.

Agrochemicals doi: 10.3390/agrochemicals4040019

Authors: Tiziana Oppedisano Silvia I. Rondon Daniel I. Thompson

Hemp (Cannabis sativa L.) cultivation in the United States has expanded rapidly over the past decade. Due to federal and state regulations, only a limited number of studies have examined the chemical options available for controlling pests on C. sativa. In the U.S., two of the most important species of arthropod pests affecting C. sativa are the beet leafhopper Circulifer tenellus Baker (Hemiptera: Cicadellidae) and the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). This study evaluated the effects of four biopesticides, Chromobacterium subtsugae, Burkholderia spp., Chenopodium ambrosioides, and azadirachtin, under greenhouse conditions against C. tenellus adults and nymphs and T. urticae adults. Biopesticides were applied to foliage using a calibrated hand sprayer. To evaluate the biopesticides’ potency, C. tenellus adults, nymphs, and mites were released 1 h after treatment; to evaluate the residual efficacy, they were released 7 days after treatment (DAT). In both experiments, C. tenellus adults, nymphs, and mites were counted 1, 3, and 7 days after release. Our results indicate that Burkholderia spp. exhibited the highest efficacy against C. tenellus adults at 7 DAT, whereas C. ambrosioides and azadirachtin caused the greatest nymphal mortality at 1 and 3 DAT, respectively. Our results show that Burkholderia spp. had the greatest potency against C. tenellus adults 7 DAT, while C. ambrosioides and azadirachtin highly affect the mortality of nymphs at 1 and 3 DAT, respectively. Treatments with C. subtsugae and C. ambrosioides showed high potency against T. urticae. Finally, C. subtsugae showed the lowest residual effect against the mite pest. The data presented in this article will add to the arsenal of information to improve the current management strategies used against these two hemp pests.

Agrochemicals doi: 10.3390/agrochemicals4040018

Authors: Víctor Coca-Ruiz

Modern agriculture faces a critical challenge from escalating fungicide resistance and the ecological impact of conventional agrochemicals. A paradigm shift is required, moving beyond simple product substitution toward an integrated technological platform. This review outlines such a platform, built on the synergy of three technologies: genome mining for rational discovery of novel antifungal compounds, synthetic biology for their scalable and cost-effective production, and RNA interference (RNAi) for highly specific pathogen control and resistance management. We argue that the integration of this trifecta—discovery, production, and targeted application—creates an adaptable pipeline for developing next-generation biofungicides. This approach transforms crop protection from a static defense to a dynamic, sustainable system capable of co-evolving with pathogens, ensuring future food security while minimizing environmental impact.

Agrochemicals doi: 10.3390/agrochemicals4030017

Authors: Leticia Nominato-Oliveira Juliana Ferreira da Silva Shayane da Silva Milhorini Larissa Lechinovski Ana Carolina de Deus Bueno Krawczyk Izonete Cristina Guiloski

Weeds have acquired resistance to commonly used herbicides, and to replace them, new products, including those of natural origin, have been produced. This study evaluated the neurotoxicity, cytotoxicity, and changes in the antioxidant system caused by Natural Herbicide (NH) in SH-SY5Y neuroblastoma cells and HaCaT dermal cells. SH-SY5Y and HaCaT cells were exposed to three concentrations of NH (NH1: 0.6; NH2: 1.56; and NH3: 3.12 µL/mL) for 24 and 72 h. In the SH-SY5Y cell line, the highest concentration of NH (NH3) caused cytotoxicity at both 24 and 72 h. At 24 h, the NH3 group increased the SOD. In the NH2 and NH3 groups, there was also an increase in AChE activity after 24 h of exposure. The NH1 group led to an increase in GSH after 72 h of exposure. As for the HaCaT strain, there was cytotoxicity and an increase in SOD and GSH at all NH concentrations and for both periods analyzed (24 h and 72 h). GST was reduced after exposure to NH2 and NH3. Thus, NH showed cytotoxicity in neural and dermal cells (SH-SY5Y and HaCaT, respectively). These results show that NH altered cellular homeostasis, and the evaluation of other toxicity mechanisms is important to clarify its safety.

Agrochemicals doi: 10.3390/agrochemicals4030016

Authors: Christos N. Kerezoudis Maria Zervou Manolis Matzapetakis Dimitrios Bilalis Konstantinos A. Aliferis

Hemp (Cannabis sativa L.) is a polymorphic species that synthesizes an array of bioactive metabolites, with cannabinoids and terpenoids constituting the major chemical classes. Until recently, the lack of legislative framework led to limited research on hemp’s plant protection and nutrition. Biostimulants have recently attracted scientific attention as sustainable alternatives to plant protection products (PPPs). Herein, we investigated the effects of biostimulant harpin (αβ) proteins and the PPP polysaccharide laminarin on hemp (cv. Futura 75), employing GC/EI/MS and 1H NMR metabolomics. Analyses demonstrated that treatments induced distinct shifts in the metabolism of the plants, thus, enabling the discovery of metabolite-biomarkers of physiological adaptation, defense mechanisms (α-linolenic acid), and bioactivity (cannabinoids). Harpin and laminarin altered the concentration of bioactive compounds such as cannabidiol, essential amino acids including L-phenylalanine and GABA, salicylate, and caffeate. Pathway analysis revealed treatment-specific modulation of key metabolic networks, with harpin triggering early, yet transient activation of phenylpropanoid- and amino acid-related pathways before broad repression, whereas laminarin maintained a more balanced regulation, sustaining defense-related biosynthesis while preserving core primary metabolism. Results advance the understanding of molecular mechanisms underlying biostimulants’ action in hemp and support their potential for improving plant health and attributes of cannabis-derived products, providing insights for its sustainable cultivation.

Agrochemicals doi: 10.3390/agrochemicals4030015

Authors: Katia Gazzetti Massimiliano Menghini Irene Maja Nanni Alessandro Ciriani Mirco Fabbri Pietro Venturi Marina Collina

Since the late 1970s, brown spot of pear (BSP), a fungal disease caused by Stemphylium vesicarium (Wallr.) Simmons, has been one of the most important pear fungal diseases in Italy. To protect orchards from BSP, frequent fungicide application is essential throughout the period spanning petal fall to the onset of fruit maturation. In Italy, boscalid was the first succinate dehydrogenase inhibitor (SDHIs) fungicide authorised against BSP; subsequently, penthiopyrad and fluxapyroxad were authorised against the disease. In 2016 and 2017, SDHI compounds were applied against BSP as solo products at the University of Bologna’s experimental farm, showing a reduction in efficacy. Stemphylium vesicarium strains were isolated from leaves and fruit, and sensitivity assays and molecular analyses were performed. In vitro tests confirmed resistance to SDHIs, and two specific single-nucleotide polymorphisms were discovered, SDHB P230L and SDHC H134R, both leading to amino acid substitutions in succinate dehydrogenase subunits and confirming the resistant phenotype.

Agrochemicals doi: 10.3390/agrochemicals4030014

Authors: Matheus Severo de Souza Kulmann Marcos Gervasio Pereira Rudi Witschoreck Mauro Valdir Schumacher

Pinus taeda plantations have been facing declining productivity in South America, especially due to competition for natural resources such as light, water, and nutrients. Competition with spontaneous vegetation in the early years is one of the main constraints on growth and biomass allocation in trees. However, the best method and timing for weed control and its impact on the productivity of Pinus taeda plantations are unknown. This study aims to evaluate whether weed control increases the growth and above-ground biomass production of Pinus taeda plantations in southern Brazil. This study was conducted at two sites with five-year-old Pinus taeda plantations in southern Brazil, with each being submitted to different weed control methods. This study was conducted in randomized blocks, with nine treatments: (i) NC—no weed control, i.e., weeds always present; (ii) PC—physical weed control; (iii) CC–T—chemical weed control in the total area; (iv) CC–R—chemical weed control in rows (1.2 m wide); (v) C6m, (vi) C12m, (vii) C18m, and (viii) C24m—weed control up to 6, 12, 18, and 24 months after planting; and (ix) COC—company operational weed control. The following parameters were evaluated: the floristic composition and weed biomass, height, diameter, stem volume, needle biomass, branches, bark, and stemwood of Pinus taeda. Control of the weed competition, especially by physical means (PC), and chemical control over the entire area (CC–T) promoted significant gains in the growth and above–ground biomass production of Pinus taeda at five years of age, particularly at the Caçador site. The results reinforce the importance of using appropriate strategies for managing weed control to maximize productivity, especially before canopy closure. In addition, the strong correlation between growth variables and the total biomass and stemwood indicates the possibility of obtaining indirect estimates through dendrometric measurements. The results contribute to the improvement of silvicultural management in subtropical regions of southern Brazil.

Agrochemicals doi: 10.3390/agrochemicals4030013

Authors: Md. Zakir Hossen S. M. Mashiur Rahman Nayeem Quazi Forhad Quadir Shaila Sharmin Phalguni Das Tasnuva Jahan Moury Laila Arafat Sathi Ronzon Chandra Das Md. Harun Or Rashid

Chitosan is an eco-friendly polysaccharide, enhancing growth and managing disease infections in fruits and vegetables. This study examines the effects of preharvest application of chitosan and calcium (Ca) on yield and postharvest chitosan coating on tomato storage. There were nine preharvest treatments, viz., T0 = control, T1 = 50 ppm chitosan, T2 = 80 ppm chitosan, T3 = 0.50% Ca, T4 = 1.0% Ca, T5 = T1 and T3 (combined), T6 = T2 and T3 (combined), T7 = T1 and T4 (combined), and T8 = T2 and T4 (combined), and three postharvest treatments, viz., C0 = control, C1 = 0.10% chitosan, and C2 = 0.20% chitosan, to examine the yield parameters and major physical and biochemical qualities of tomatoes on different days after postharvest storage (DAPS). The results revealed that chitosan and Ca treatments had a significant influence on yield while showing an insignificant impact on the biochemical qualities of fresh-harvested tomatoes. Postharvest application of chitosan coatings effectively reduced weight loss and shrinkage (34–37%) compared to the control. At 20 DAPS, only the 0.20% solution met the marketable threshold of ≥5.0, while the control failed in 100% of the samples. As storage duration increased, titratable acid and vitamin C decreased, while lycopene and sugar content rose in tomatoes. This research indicates that foliar spraying with 80 ppm chitosan during fruit initiation significantly boosts tomato yield, and a 0.20% chitosan coating on postharvest tomatoes enhances longevity and preserves biochemical quality.

Agrochemicals doi: 10.3390/agrochemicals4030012

Authors: Anthony Cartwright Mohammad Zargaran Anagha Wankhade Astrid Jacobson Joan E. McLean Anne J. Anderson David W. Britt

Surfactants are widely utilized in agriculture as emulsifying, dispersing, anti-foaming, and wetting agents. In these adjuvant roles, the inherent biological activity of the surfactant is secondary to the active ingredients. Here, the hydrophilic non-ionic surface-active tri-block copolymer Pluronic® F68 is investigated for direct biological activity in wheat. F68 binds to and inserts into lipid membranes, which may benefit crops under abiotic stress. F68’s interactions with Triticum aestivum (var Juniper) seedlings and a seed-borne Bacillus spp. endophyte are presented. At concentrations below 10 g/L, F68-primed wheat seeds exhibited unchanged emergence. Root-applied fluorescein-F68 (fF68) was internalized in root epidermal cells and concentrated in highly mobile endosomes. The potential benefit of F68 in droughted wheat was examined and contrasted with wheat treated with the osmolyte, glycine betaine (GB). Photosystem II activity of droughted plants dropped significantly below non-droughted controls, and no clear benefit of F68 (or GB) during drought or rehydration was observed. However, F68-treated wheat exhibited increased transpiration values (for watered plants only) and enhanced shoot dry mass (for watered and droughted plants), not observed for GB-treated or untreated plants. The release of seed-borne bacterial endophytes into the spermosphere of germinating seeds was not affected by F68 (for F68-primed seeds as well as F68 applied to roots), and the planktonic growth of a purified Bacillus spp. seed endophyte was not reduced by F68 applied below the critical micelle concentration. These studies demonstrated that F68 entered wheat root cells, concentrated in endosomes involved in transport, significantly promoted shoot growth, and showed no adverse effects to plant-associated bacteria.

Agrochemicals doi: 10.3390/agrochemicals4030011

Authors: Tyler M. Wilson Alma Laney Zabrina Ruggles Richard E. Carlson

The conventional agricultural industry largely relies on pesticides to maintain healthy and viable crops. Application of fungicides, both pre- and post-harvest of crops, is the go-to method for avoiding and eliminating Botrytis cinerea, the fungal pathogen responsible for gray mold. However, conventional fungicides and their residues have purported negative environmental and health impacts. Natural products, such as essential oils, are viewed as a promising alternative to conventional fungicides. The current research is an in vitro study on the antifungal activity of a natural water-based fungicide (N.F.), which uses a blend of essential oils (ajowan, cassia, clove, eucalyptus, lemongrass, oregano) as the active ingredients against B. cinerea. Compared to conventional fungicides tested at the same concentration (50 μL/mL), those with active ingredients of myclobutanil or propiconazole; the N.F. demonstrated significant (F(3,16) = 54, p = <0.001) and complete fungal growth inhibition. While previous research has largely focused on the antifungal properties of single essential oils and/or isolated compounds from essential oils, this research focuses on the efficacy of using a blend of essential oils in a proprietary delivery system. This research is of importance to the fields of agronomy, ecology, and health sciences.

Agrochemicals doi: 10.3390/agrochemicals4030010

Authors: Jong-Hyeong Lee Hyun-Hwoi Ku

This study aimed to evaluate the agronomic performance and environmental impact of controlled-release coated fertilizers (CRCFs) in upland maize systems. Specifically, we sought to determine the optimal nitrogen (N) application rate that maximizes nitrogen use efficiency (NUE) and minimizes nutrient runoff, while maintaining yield comparable to conventional fertilization practices. A two-year field experiment (2017–2018) was conducted to assess CRCF formulations composed of urea, MAP, and potassium sulfate encapsulated in LDPE/EVA coatings with talc, humic acid, and starch additives. Treatments included various nitrogen application rates (33–90 kg N ha−1) using CRCF and a conventional NPK fertilizer (150 kg N ha−1). Measurements included fresh ear yield, aboveground biomass, NUE, and concentrations of total N (TN), nitrate N (NO3−–N), and total P (TP) in surface runoff. Statistical analyses were performed using linear and quadratic regression models to determine yield responses and agronomic optimal N rate. CRCF treatments produced yields comparable to or exceeding those of conventional fertilization while using less than half the recommended N input. The modeled agronomic optimum N rate was 88.4 kg N ha−1, which closely matched the maximum observed yield. CRCF application significantly reduced TN, NO3−–N, and TP runoff in 2017 and improved NUE up to 71.2%. Subsurface placement and sigmoidal nutrient release contributed to reduced nutrient losses. CRCFs can maintain maize yield while reducing N input by approximately 40%, aligning with climate-smart agriculture principles. This strategy enhances NUE, reduces environmental risks, and offers economic benefits by enabling single basal application. Further multi-site studies are recommended to validate these findings under diverse agroecological conditions.

Agrochemicals doi: 10.3390/agrochemicals4020009

Authors: Anna B. O. Moura Gustavo B. A. Silva Anna C. C. Paimel Eildson S. O. Silva Lucas G. Mota Camila F. D. Duarte Carla H. A. Cabral Carlos E. A. Cabral

Foliar fertilizers are low-cost agrochemicals used in pastures, and further research is needed regarding their impact on tropical grasses. Therefore, the objective of this research was to evaluate the effects of foliar fertilization on the development of tropical grasses. Two experiments, consisting of five treatments and four replicates, were carried out. Each experiment was carried out using the following grasses: Zuri grass (Megathyrsus maximus Jacq. cv. Zuri) and ipypora grass (hybrid of Urochloa brizantha × Urochloa zizizensis). In each experiment, ten treatments were evaluated using a 2 × 5 factorial design with four replications. Treatments combined two soil fertilization strategies (with and without nitrogen) and five foliar fertilization strategies, which consisted of a control treatment without foliar fertilization and four application times: immediately after defoliation (0 leaves) and with 1, 2, and 3 expanded leaves. The grass height, tiller population density (TPD), leaf number (LN), forage dry mass (FDM), individual leaf mass (ILM) were evaluated. In the absence of soil fertilization, foliar fertilizer application had no effect on the development of the grasses (p > 0.05). Foliar fertilization did not affect the FDM of Ipyporã and Zuri grass under any of the conditions evaluated (p > 0.05). When applied in the soil fertilize with nitrogen, foliar fertilizer increased LN by 24% for two grasses (p < 0.05). For Zuri grass, foliar fertilization reduced individual leaf mass by 19% (p < 0.05). Thus, foliar fertilizer does not increase the productivity of tropical grasses, with small effects on the leaf’s appearance in Ipyporã and Zuri grass, without altering the forage mass, which necessitates new studies with agrochemicals, new doses, and concentrations of nitrogen.

Agrochemicals doi: 10.3390/agrochemicals4020008

Authors: Maria Y. Chavez Armando Villa Ignacio Joshua K. Craver Jennifer Bousselot

Insect frass is the left-over side stream from mass rearing insects as food and feed. Research indicates that black soldier fly, Hermetia illucens, larvae (BSFL) frass can improve the yield of leafy greens while also increasing nutrient uptake. Two studies evaluated the impact of BSFL frass on two Brassicaceae crops: kale (Brassica oleracea) and mustard (Sinapis alba). In Study 1, greenhouse potting mixes comprised of 10% BSFL frass produced kale and mustard fresh and dry weights, relative chlorophyll concentrations, and nitrogen concentration in plant tissues that were comparable to a 100% peat mix control. In mustard tissue, phosphorus and potassium concentrations were higher in the BSFL 10% treatment compared to the control. This provides further motive for incorporating frass into peat-based substrates to reduce peat consumption and extraction. In Study 2, Liquid BSFL frass tea was applied to kale in an outdoor container study. The frass tea only treatment produced the worst outcomes for yield. However, a mixture of frass tea and traditional fertilizer resulted in comparable yield to a control provided the same volume in solely fertilizer. With further research, frass tea could be supplemented to reduce conventional fertilizers.

Agrochemicals doi: 10.3390/agrochemicals4020007

Authors: Navjot Singh Brar Parminder Singh Sandhu Anil Kumar Prabjeet Singh Simerjeet Kaur

Large weed infestation is a major problem in dry direct-seeded rice (DSR). Chemical weed control serves as a crucial component for integrated weed management in DSR. Over the last decade, herbicide use has increased from 42 to 55%, and the worldwide contamination of water resources and food by herbicides is a major health issue. In the present study, the use of herbicides in three different establishment methods of rice was examined with the objective to present and discuss the herbicide use pattern and cost of weed control. For this, a field-wide survey was conducted over an area of 165.4 ha in eight villages of the Tarn Taran District of Punjab, India. For two DSR methods, during the initial stage of crop growth, the weed infestation was reported to be less in moist fields sown with direct seeding (soil moisture in the field capacity stage) after pre-sowing irrigation (DSR-PSI). The herbicide use and cost of weed control under DSR-PSI conditions were similar to that of puddled transplanted rice, but were significantly lower than that of direct seeding in dry fields (rice seeds are sown in dry fields, and irrigation is applied immediately after sowing), i.e., DSR-IAS. Therefore, the DSR-PSI method of rice establishment can ensure minimum dependence on herbicides, as well as other benefits of direct seeding. Thus, there is a need to promote the DSR-PSI method over the DSR-IAS method among farmers in order to reduce herbicide use in DSR and ensure environmental safety.

Agrochemicals doi: 10.3390/agrochemicals4020006

Authors: Emilee Calero-Rios Miryam Borbor-Ponce Sphyros Lastra Richard Solórzano

Sustainable fertilization using local resources such as manure is crucial for soil health. This study evaluated the potential of guinea pig manure to replace mineral fertilizers in hard yellow maize (hybrid INIA 619) under Peruvian coastal conditions. A split-plot design tested four doses of guinea pig manure (0, 2, 5, 10 t⋅ha−1) and four levels of mineral fertilization (0%, 50%, 75%, 100%). The study assessed plant height, ear characteristics, yield, and nutritional quality parameters. The results indicated that 100% mineral fertilization led to the highest plant height (229.67 cm) and grain weight (141.8 g). Yields of 9.19 and 9.08 t⋅ha−1 were achieved with 5 and 10 t⋅ha−1 of manure, while 50% mineral fertilization gave 8.8 t⋅ha−1, similar to the full dose (8.7 t⋅ha−1). The protein content was highest with 10 t⋅ha−1 of manure combined with mineral fertilization. However, no significant differences were found between the 50%, 75%, and 100% mineral fertilizer doses. In conclusion, applying guinea pig manure improved nutrient use efficiency, yield, and grain protein quality in maize, reducing the need for mineral fertilizers by up to 50%. This provides a sustainable fertilization strategy for agricultural systems.

Agrochemicals doi: 10.3390/agrochemicals4020005

Authors: Jian Huang Xiuying Piao Yanming Zhou Simeng Li

Jian Huang, Xiuying Piao, and Yanming Zhou were not included as authors in the original publication [...]

Agrochemicals doi: 10.3390/agrochemicals4010004

Authors: Ioannis Vagelas

Wheat pathogens pose a significant risk to global wheat production, with climate change further complicating disease dynamics. Effective management requires a combination of genetic resistance, cultural practices, and careful use of chemical controls. Ongoing research and adaptation to changing environmental conditions are crucial for sustaining wheat yields and food security. Based on selective academic literature retrieved from the Scopus database and analyzed by a bibliographic software such as the VOSviewer we discussed and focused on various aspects of current and future strategies for managing major wheat pathogens and diseases such as Tan spot, Septoria tritici blotch, Fusarium head blight, etc. Chemical management methods, such as the use of fungicides, can be effective but are not always preferred. Instead, agronomic practices like crop rotation and tillage play a significant role in managing wheat diseases by reducing both the incidence and severity of these diseases. Moreover, adopting resistance strategies is essential for effective disease management.

Agrochemicals doi: 10.3390/agrochemicals4010003

Authors: Konstantinos B. Simoglou Paraskevi El. Skarpa Emmanouil Roditakis

This study explores consumer perceptions of the Greek food system, focusing on safety concerns related to pesticide residues. Utilizing a qualitative research design, thematic analysis was conducted on data collected from 1024 participants through an online survey platform between May and November 2024. Participants, representing diverse demographics across Greece, provided insights into their experiences and concerns regarding food safety. The analysis revealed significant themes, including a crisis of confidence in governance, demands for transparency, and skepticism towards food system actors. Participants expressed disillusionment with the state’s role in ensuring food safety and highlighted the need for a governance framework that aligns with community values. The findings underscore the importance of empowering consumers with accurate information to foster informed decision-making and rebuild trust in the food system. Ultimately, this study emphasizes the necessity for a transformative approach to food governance that incorporates diverse voices and perspectives, aiming to create a more equitable and sustainable food system in Greece. These insights contribute to the broader discourse on food citizenship and the collective responsibilities of all stakeholders in ensuring food safety and integrity.

Agrochemicals doi: 10.3390/agrochemicals4010002

Authors: Brant W. Touchette Daniel S. Cox Rebecca L. Carranza Harriette Palms

Seed enhancements involve post-harvest modifications that improve germination and plant performance. One form of enhancement involves coatings, which encompasses encrusting, pelleting, and film coats. These coatings may contain agrichemicals, such as fungicides and insecticides, and can foster conformational changes that improve the plantability of small or irregularly shaped seeds. Seed encapsulation using pharmaceutical capsules can be viewed as an extension of seed coatings where seeds and other beneficial agrichemicals can be combined into a single plantable unit. For many crops, direct contact with high levels of conventional fertilizers may induce some level of phytotoxicity, and early studies involving fertilizer-enriched seed coatings resulted in decreased seedling emergence and diminished plant performance. Encapsulation, however, provides greater delivery volumes compared to other coatings and may offer some degree of separation between seeds and potentially phytotoxic agrochemicals. This study considered tomato seed encapsulation with controlled-release fertilizers. In general, seed exposure to gelatin-based capsules delayed germination by 2- to 3- days. Nevertheless, seed encapsulation improved plant performance including increased plant height and dry mass production by as much as 75 and 460%, respectively. These growth responses mitigated any effects attributed to germination delays. Moreover, higher levels of controlled-release fertilizers (≥800 mg) fostered earlier flower induction by up to 3 weeks. Collectively, the results suggest that seed encapsulation can be an effective way to deliver fertilizers to plants in a manner that could reduce overall fertilizer application rates and possibly lessen the quantity of plant nutrient input necessary for tomato cultivation.

Agrochemicals doi: 10.3390/agrochemicals4010001

Authors: Christos G. Athanassiou Christos I. Rumbos

Over the past decade, insect farming has garnered significant scientific and commercial attention due to its potential as a sustainable and efficient alternative nutrient source for both animal feed [...]

Agrochemicals doi: 10.3390/agrochemicals3040016

Authors: Lena Goritschnig Thomas Durstberger Helmut Burtscher-Schaden Johann G. Zaller

It is debated whether the ecotoxicity of active substances (ASs) contained in synthetic pesticides applied in conventional agriculture (conASs) differs from nature-based ASs used in organic agriculture (orgASs). Using the official pesticide use statistics, we evaluated the ecotoxicity of ASs used in apple and grapevine production in Austria. In 2022, 49 conASs and 21 orgASs were authorized for apple production and 60 conASs and 23 orgASs were authorized for grapevine production in Austria. Based on the latest publicly available data on the actual use of pesticides in apple and grapevine production (from the year 2017), we evaluated their ecotoxicity based on information in the freely accessible Pesticide Properties and Bio-Pesticides Databases. The results showed that although the amount of ASs applied per hectare of field was higher in organic farming, the intrinsic toxicities of ASs used in conventional farming were much higher. The number of lethal toxic doses (LD50) of ASs applied in conventional apple orchards was 645%, 15%, and 6011% higher for honeybees, birds, and earthworms, respectively, than in organic apple production. In conventional vineyards, lethal doses for honeybees, birds, and earthworms were 300%, 129%, and 299% higher than in organic vineyards. We conclude that promoting organic farming would therefore contribute to the better protection of biodiversity on agricultural land and beyond.

Agrochemicals doi: 10.3390/agrochemicals3030015

Authors: Hannah E. Wright-Smith Timothy W. Coolong A. Stanley Culpepper Taylor M. Randell-Singleton Jenna C. Vance

Industrial hemp (Cannabis sativa) production is complex, with strict regulatory constraints and challenges associated with a lack of labeled pesticides due to its status as a novel crop in the US. Four experiments were conducted in 2020 and 2021 to establish herbicide tolerances for hemp production in the coastal plain of Georgia, USA. Objectives included evaluating hemp response to pretransplant or posttransplant herbicides, determining if planting method influenced herbicide injury from residual preplant applied herbicides, and understanding how plastic mulch may influence hemp flower yields. When applied one day prior to transplanting, maximum hemp crop visual injury was less than 12% compared to the untreated control, with acetochlor, flumioxazin, fomesafen, pendimethalin, and norflurazon while dithiopyr, halosulfuron, isoxaben, and isoxaflutole resulted in greater than 50% injury. Posttransplant applications of S-metolachlor, acetochlor, pendimethalin, and clethodim resulted in less than 15% injury while halosulfuron, metribuzin, trifloxysulfuron, imazethapyr, and prometryn applications resulted in greater than 50% injury to plants. Preplant and posttransplant applied herbicides were found to have little effect on total tetrahydrocannabinol (THC), cannabidiol (CBD), or total cannabinoids in the dry flower after harvest. In a separate experiment, injury from halosulfuron and metribuzin was 52% to 56% less when planted with a mechanical transplanter as compared to the practice of using a transplant wheel to depress a hole in the soil followed by hand transplanting. In the final experiment, hemp dry flower yield in a non-plastic mulched (bareground) system was similar to that in a plastic mulched system. However, early season plant above-ground biomass was less in the plastic mulched system, which may have been due to elevated soil temperatures inhibiting early season growth.

Agrochemicals doi: 10.3390/agrochemicals3030014

Authors: Upendra M. Sainju

Using predicted potential N mineralization (PNM) from its relationship with CO2 flush at 1 d incubation (CF) of soil samples in recommended N rates can reduce N fertilization rates for crops. This study used predicted PNM at the 0–15 cm depth to reduce N fertilization rates and examined spring wheat (Triticum aestivum L.) yields at two sites (Froid and Sidney) in Montana, USA. Cropping sequences at Froid were fall and spring till continuous spring wheat (FSTCW), no-till continuous spring wheat (NTCW1), no-till spring wheat–pea (Pisum sativum L.) (NTWP1), and spring till spring wheat–fallow (STWF). At Sidney, cropping sequences were conventional till spring wheat–fallow (CTWF), no-till spring wheat–fallow (NTWF), no-till continuous spring wheat (NTCW2), and no-till spring wheat–pea (NTWP2). Soil samples collected to a depth of 15 cm in September 2021 at both sites were analyzed for CF, PNM, and NO3-N contents, from which the reduction in N fertilization rate (RNFA) and the amount of N fertilizer applied (ANFA) to 2022 spring wheat were determined. In April 2022, spring wheat was grown with or without predicted PNM and annualized crop yields were compared. The CF and PNM were 114–137% greater for NTWP1 than STWF at Froid and 26–80% greater for NTCW2 than CTWF and NTWF at Sidney. The reduction in N fertilization rate was 26–102% greater for NTWP1 at Froid and 8–10% greater for NTCW2 and NTWF than other cropping sequences at Sidney. Annualized crop yield was 26–60% lower for crop–fallow than continuous cropping, but was not significantly different between with or without PNM at both sites. Using PNM can significantly reduce N fertilization rates for crops while sustaining dryland yields.

Agrochemicals doi: 10.3390/agrochemicals3030013

Authors: Perla N. Chávez-Dulanto Oliver Vögler Salomón Helfgott-Lerner Fernando P. Carvalho

The food security of Lima—Peru’s capital city, which shelters over 30% of the total country’s population—depends on the food production of its nearest agricultural areas, the Chancay-Huaral and Chillón valleys, wherein agrochemicals are widely used. This study primarily aimed to determine the characteristics of pesticide use in these two valleys, located 83 and 30 km north of Lima City, respectively. A second aim was to assess whether proximity to Lima provides access to technical assistance regarding agricultural activities. A questionnaire-based survey assessing socioeconomic aspects, occupational exposure, and agrochemical-related knowledge was conducted on a sample of 102 participants (farmers and fieldworkers). The results revealed that the average age for starting to handle pesticides was 15 years, while life-long occupational-exposure averaged 30 years. Most pesticides used were organophosphates and carbamates. Personal protective equipment was not used and, therefore, dermal exposure and inhalation were major routes of intoxication. Despite their proximity to Lima, both valleys lack an official agronomic advisory agency, and this void has been occupied by agrochemical manufacturing companies and trading houses focused on increasing their sales. Based on the results, it is urgent to implement an official technical advisory service and a capacity-building program on pesticide use in Peru, as well as the implementation of measures for improved control, trade, and storage of pesticides. Simultaneously, a permanent epidemiological surveillance at the country level is needed to improve public health and to contribute to achieving the Sustainable Development Goals of the United Nations’ 2030 Agenda in Peru.

Agrochemicals doi: 10.3390/agrochemicals3020012

Authors: Jian Huang Xiuying Piao Yanming Zhou Simeng Li

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.

Agrochemicals doi: 10.3390/agrochemicals3020011

Authors: Luis F. Aristizábal

In this case study, the current situation faced by coffee growers attempting to control coffee leaf rust (Hemileia vastatrix) in Hawaii is reported. CLR is considered the most devastating disease affecting coffee crops worldwide and was detected in Hawaii in 2020. Three small coffee farms from the South Kona district of Hawaii Island were selected. The goals of this case study were to: (1) assist coffee growers in the early detection of CLR incidence, and consequently support farmers with recommendations for control, (2) record agronomic information and management practices, and (3) estimate the cost to control CLR during 2021 and 2022 seasons. Low CLR incidence (<4%) was initially observed at all farms (January–June 2021), but increased as the harvest began, ending the season (December 2021) at 77%, 21% and 6% incidence at farms 1, 2 and 3, respectively. At the end of 2022 season (December), CLR incidence reached 43%, 20% and 3% at farms 1, 2 and 3, respectively. The number of sprays per season (5–10), the type of fungicides applied (preventive, curative), the timing of sprays, the efficacy of applications and weather conditions all played a role in determining the infection rates at each farm. Effective control of CLR is possible in Hawaii if the sprays of fungicides are carried out with the right products, appropriate timing and good coverage.

Agrochemicals doi: 10.3390/agrochemicals3020010

Authors: Chisom Augusta Okoro Abbas El-Hasan Ralf T. Voegele

Apple scab incited by the ascomycete Venturia inaequalis poses a significant threat to apple cultivation, necessitating a reassessment of existing disease management strategies. Attempts to manage apple scab include diverse approaches like developing disease forecasting models and the extensive application of synthetic chemical fungicides. However, the efficacy of these methods is compromised by inconsistencies, environmental concerns, and the pathogen’s resistance, necessitating the exploration of alternative sustainable strategies. Addressing the challenges associated with apple scab management, this review strongly supports a shift towards the integration of biological control agents (BCAs). Emphasising the transformative synergy between BCAs and their bioactive secondary metabolites, we highlight their efficacy in advancing precision disease control through innovative and sustainable solutions. The review effectively presents a strong justification for the integration of BCAs and their by-products into apple scab management, offering insights into associated benefits, risks, and challenges while outlining promising prospects. Ultimately, it is expected to drive the adoption of environmentally conscious practices for effective apple scab management.

Agrochemicals doi: 10.3390/agrochemicals3020009

Authors: Mariana Rodrigues Bueno Guilherme Sousa Alves Sérgio Macedo Silva Tiago Seiji S. Hachiya Hasle Thiago S. Guimarães Gustavo Araújo Costa Felipe Soares Gonçalves Mateus A. V. G. Oliveira

This study aimed to evaluate the efficiency of air assistance associated with electrostatic spraying in terms of spray deposition and yield (Experiment 1), and the coverage and droplet density on soybean crops at different working speeds (Experiment 2). The treatments in Experiment 1 corresponded to combinations of electrostatic systems associated with air assistance at three airspeeds (21, 25, and 30 m·s−1) plus a conventional treatment without electrostatic or air assistance. The treatments in Experiment 2 corresponded to three working speeds (3.3, 4.2, and 5.0 m·s−1) with or without the use of an electrostatic system. All applications were performed with a self-propelled sprayer, delivering 75 L·ha−1 with ATR 2.0 nozzles. A blue tracer, detectable as absorbance with a spectrophotometer, was added to the spray solution to evaluate deposition. The results indicate that an air assistance at 21 m·s−1 plus electrostatic system increased the amount of spray deposited on the middle and top leaves of the plants in relation to the conventional system, with yield increments of up to 621 kg·ha−1. The slowest working speed (3.3 m·s−1) combined with air assistance and an electrostatic system provided the greatest spray deposition, droplet coverage, and density on the bottom leaves of soybean crops.

Agrochemicals doi: 10.3390/agrochemicals3010008

Authors: Qudus O. Uthman Miguel Vasconez Davie M. Kadyampakeni Yu Wang Demetris Athienitis Jawwad A. Qureshi

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts.

Agrochemicals doi: 10.3390/agrochemicals3010007

Authors: Joshua Chavana Neelendra K. Joshi

Pollinators play important roles in providing pollination services, maintaining biodiversity, and boosting crop production. Even though pollinators are essential to the environment and agriculture, their decline has been noted across multiple studies in the recent past. Both natural and anthropogenic factors have contributed to their decline. Much of the focus has been placed on climate change, habitat loss, pests and pathogens, and synthetic pesticides, but relatively little is known about the effects of biopesticides. Biopesticides are biological control agents derived from living organisms and are classified into three groups: microbial, biochemical, and plant-incorporated protectant-based products. Biopesticides are formulated similarly to their synthetic counterparts and are readily available and used within urban and agricultural settings by pest management experts and household residents. The general public and much scientific literature support the prevailing idea that biopesticides are environmentally safe and pollinator friendly in comparison with synthetic versions. However, such generalizations are based on studies with a few key pollinator species and may not be relevant to several other species that provide crop pollination services. Studies focused on native pollinators have shown that some biopesticides have lethal and sublethal effects. Because each biopesticide exhibits varying effects across pollinator species, it could be dangerous to generalize their non-toxicity across taxa and environmental settings. In this article, recent research in this direction is discussed.

Agrochemicals doi: 10.3390/agrochemicals3010006

Authors: Yasasvi Jayakodi Punniamoorthy Thiviya Ashoka Gamage Philippe Evon Terrence Madhujith Othmane Merah

The importance of antioxidants has gained much attention due to the increase in the prevalence of various non-communicable diseases such as cancer, diabetes mellitus, and cardiovascular diseases, which occur due to excess reactive species. The widespread use of synthetic antioxidants in the food industry has raised concerns about their potential harmful effects on health. As a result, the utilization of natural antioxidants to preserve food and as a source of dietary antioxidants has gained attention. Essential oils extracted from Apiaceae family plants are an excellent source of antioxidants. In this review, research findings regarding the antioxidant activity of selected Apiaceae family members and their applications are discussed.

Agrochemicals doi: 10.3390/agrochemicals3010005

Authors: Joanne K. Daggy David M. Haas Yunpeng Yu Patrick O. Monahan David Guise Éric Gaudreau Jessica Larose Charles M. Benbrook

Currently, there are no known human biomonitoring studies that concurrently examine biomarkers of dicamba and 2,4-D. We sought to compare biomarkers of exposure to herbicides in pregnant women residing in the US Midwest before and after the adoption of dicamba-tolerant soybean technology using urine specimens obtained in 2010–2012 from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (N = 61) and in 2020–2022 from the Heartland Study (N = 91). Specific gravity-standardized concentration levels for each analyte were compared between the cohorts, assuming data are lognormal and specifying values below the LOD as left-censored. The proportion of pregnant individuals with dicamba detected above the LOD significantly increased from 28% (95% CI: 16%, 40%) in 2010–2012 to 70% (95% CI: 60%, 79%) in 2020–2022, and dicamba concentrations also significantly increased from 0.066 μg/L (95% CI: 0.042, 0.104) to 0.271 μg/L (95% CI: 0.205, 0.358). All pregnant individuals from both cohorts had 2,4-D detected. Though 2,4-D concentration levels increased, the difference was not significant (p-value = 0.226). Reliance on herbicides has drastically increased in the last ten years in the United States, and the results obtained in this study highlight the need to track exposure and impacts on adverse maternal and neonatal outcomes.

Agrochemicals doi: 10.3390/agrochemicals3010004

Authors: Yuechun Zeng Shaolin Sun Pengfei Li Xian Zhou Jian Wang

Recent advances in the microbial degradation of persistent organic pollutants have the potential to mitigate the damage caused by anthropogenic activities that are harmfully impacting agriculture soil ecosystems and human health. In this paper, we summarize the pollution characteristics of neonicotinoid insecticides (NNIs) in agricultural fields in China and other countries and then discuss the existing research on screening for NNI-degrading functional bacterial strains, their degradation processes, the construction of microbial consortia, and strategies for their application. We explore the current needs and solutions for improving the microbial remediation rate of NNI-contaminated soil and how these solutions are being developed and applied. We highlight several scientific and technological advances in soil microbiome engineering, including the construction of microbial consortia with a broad spectrum of NNI degradation and microbial immobilization to improve competition with indigenous microorganisms through the provision of a microenvironment and niche suitable for NNI-degrading bacteria. This paper highlights the need for an interdisciplinary approach to improving the degradation capacity and in situ survival of NNI-degrading strains/microbial consortia to facilitate the remediation of NNI-contaminated soil using strains with a broad spectrum and high efficiency in NNI degradation.

Agrochemicals doi: 10.3390/agrochemicals3010003

Authors: Eleftheria Travlou Nikolaos Antonopoulos Ioannis Gazoulis Panagiotis Kanatas

Herbicide volatility and drift are serious problems for chemical weed control. The extended use of dicamba, especially due to the commercial release of dicamba-resistant crops, revealed many off-target dicamba injury issues for sensitive crops. The objective of the present study is to give information on the chemical properties and volatility of dicamba and highlight some key issues, while a systematic review of the recently reported cases is attempted. Unfortunately, the problem is increasing, with a huge majority of the injuries reported in the USA, but it is also present in many other countries. Several arable, horticultural, and perennial crops suffer from such damage. Specific measures and approaches are suggested in order to quantify, reduce, and prevent such problems, while the training of farmers and stakeholders and further research are certainly required for the optimization of the several alternative options.

Agrochemicals doi: 10.3390/agrochemicals3010002

Authors: Anastasia Tsekoura Ioannis Gazoulis Nikolaos Antonopoulos Angeliki Kousta Panagiotis Kanatas Ilias Travlos

Sustainable crop and weed management is among the crucial challenges in the era of the EU Green Deal. The main objective of the present study was to apply an innovative approach for the rapid assessment of herbicide efficacy in maize (Zea mays) crop in four different trials during two years. Weed NDVI values were recorded at two weeks after treatment, while weed biomass and crop yield were also measured. The results revealed significant differences between the several treatments. In many cases, significant effects of herbicide application on the normalized difference vegetation index (NDVI) values and weed biomass were noticed at two weeks after treatment. Moreover, the mixture nicosulfuron + rimsulfuron + mesotrione resulted in high efficacy on the crop yield of all fields. Consequently, our approach can allow for an early prediction of the real field efficacy of several herbicides and thus act as an alert for the farmers in order to choose the most efficient herbicide, avoid applications of low efficacy and reduce the herbicide inputs.

Agrochemicals doi: 10.3390/agrochemicals3010001

Authors: Amanda R. Streeter Anthony Cartwright Mohammad Zargaran Anagha Wankhade Anne J. Anderson David W. Britt

Plant probiotic bacteria are being increasingly used to maximize both the productivity and quality of field crops. Pseudomonas chlororaphis O6 (PcO6) is a plant root colonizer with probiotic activities. This bacterium produces an array of metabolites, including a group of phenazines that are functional in plant protection. The paper reports responses of PcO6 to a nonionic triblock copolymer surfactant, Pluronic F68. This Pluronic exhibits membrane “healing” activity and improves cryopreservation recovery in eukaryotic cells. The product is FDA-approved and is applied as an adjuvant in formulations used in agriculture, medicine, and biotechnology. Growth of PcO6 on lysogeny broth at 25 °C was unhindered by 0.1 and 1.0 g/L F68, reduced at 10 g/L, and with significant inhibition at 100 g/L F68; micelle formation could account for inhibited growth at higher doses. Phenazine production was not changed by F68, whereas the surfactant activity of F68 induced the spread of bacterial colonization on 0.5% agar. Exposure of cells to fluorescein-labeled F68 resulted in intense fluorescence, stable to washing, showing a direct association of the Pluronic with the bacterium. However, neither protection nor harm was found for PcO6 cells suspended in either 0.1% or 1% F68 after three freeze (−20 °C)/thaw cycles. These findings suggest that F68 could be compatible for use in agricultural formulations with little effect on probiotics such as PcO6.

Agrochemicals doi: 10.3390/agrochemicals2040034

Authors: Sushant Raj Sharma Md Munir Mostafiz Kyeong-Yeoll Lee

Trichome is a hair-like structure involved in mechanical and chemical defenses of plants against herbivorous insects. Nicotiana benthamiana, a wild tobacco plant, has well-developed glandular trichomes that secrete sugar esters with potent repellent and insecticidal properties. However, there is a lack of information about the effectiveness of trichome extract in the control of plant-sapping insects. The objective of this study was to investigate the effects of N. benthamiana trichome exudates on Bemisia tabaci MED (Gennadius) (Hemiptera: Aleyrodidae), a highly destructive insect pest that poses significant threats to both vegetable and ornamental plants globally. First, we determined the host preference and mortality of B. tabaci adults using the choice test and feeding assay towards tomato and N. benthamiana plants. B. tabaci preferred tomato over N. benthamiana plants. Second, we extracted N. benthamiana trichome exudates by washing the leaves with either water or ethanol and evaluated their oral toxicities against B. tabaci adults using a parafilm feeding chamber containing 20% sucrose solution. Oral ingestion of both extracts significantly increased mortality in a concentration-dependent manner. Oral ingestion of ethanol-washed 10% trichome extract caused >60% mortality in B. tabaci adults after 36 h. Third, trichome exudates were concentrated by drying to obtain a powder form, which was more potent in killing whiteflies than the liquid form. Oral ingestion of 1% trichome powder was completely lethal to B. tabaci within 36 h. N. benthamiana trichome exudates are highly toxic to B. tabaci through oral ingestion, suggesting that N. benthamiana can be used as a potential natural pesticide for whitefly management.

Agrochemicals doi: 10.3390/agrochemicals2040033

Authors: Vassya Bankova Milena Popova

Recently, the search for sustainable and environmentally friendly agrochemicals from natural origin is steadily growing. Propolis, a resinous substance collected by honeybees, well known for its diverse biological activities, has attracted the attention of scientists and farmers with its agrochemical potential in the last years. This review article aims to delve into the fascinating world of propolis and its utilization in agriculture. Here, we provide a brief overview of propolis: its chemical composition and the bioactive substances responsible for its biological properties. The effectiveness of propolis in controlling common pests and diseases that affect crops, suppressing postharvest illnesses of fruits and vegetables, stimulating plant defenses and increasing stress resistance, is reviewed. Discussion of the challenges and future perspectives related to the integration of propolis in agriculture is also one of our objectives, including chemical variability, standardization and regulatory considerations. We also focused on the latest research trends and technological advances that promise to unlock the full potential of propolis as a sustainable agricultural tool.

Agrochemicals doi: 10.3390/agrochemicals2040032

Authors: Dmitry S. Volkov Olga B. Rogova Svetlana T. Ovseenko Aleksandr Odelskii Mikhail A. Proskurnin

Membrane fractionation with track-etched membranes was used to size-profile the microelement composition of water-extractable soil colloids (WESCs). The aim of the study is the element composition of narrow WESC fractions of typical chernozems in the range of 0.01–10 µm. Micro-/ultrafiltration through a cascade of track-etched polycarbonate membrane filters with pore sizes of 5, 2, 1, 0.8, 0.4, 0.2, 0.1, 0.05, 0.03, and 0.01 µm at room temperature was used. ICP–AES using direct spraying of obtained fractions without decomposition was used; Al, Ba, Cd, Cr, Cu, Fe, Mn, Si, Sr, Ti, Zn, Ca, K, Mg, Na, P, and S were found. Narrow WESC fractions differ significantly. For macro- and microelements, maximum amounts of Si, Al, Fe, and Ti and their maximum percentages are observed in fractions with sizes above 1 µm, while Ca, Mg, Mn, Cu, Zn, K, and S are accumulated more in fractions with sizes below 1 µm. The developed approach provides preparative isolation of a detailed set of narrow WESC fractions in the micrometer–nanometer range. This provides element soil profiles that reveal distinct differences and the individual character of each fraction as well as trends in changes in the mineral matrix and microelement composition with fraction size.

Agrochemicals doi: 10.3390/agrochemicals2040031

Authors: Eric Tossou Ghislain Tepa-Yotto Genevieve M. Tchigossou Murielle F. Soglo Serge Foukmeniok Mbokou Honorine Hortense Bougna Tchoumi Aimé H. Bokonon-Ganta Manuele Tamò Rousseau Djouaka

In Benin, synthetic insecticides are the main pest control option used by farmers to protect and enhance their production. However, failures to control the target pests are often observed after application and may be related to agricultural practices or insecticide quality. The present work was designed to assess a rapid, simple, and reliable analytical method for detecting and quantifying the most commonly used insecticides (λ-cyhalothrin and acetamiprid) in Benin. The analytical standard technical grade separation was performed by gradient reversed-phase high-performance liquid chromatography on a C18 stationary-phase column. The mobile phase consisted of a mixture of acetonitrile/water using a gradient flow. The flow rates were 1 and 1.4 mL·min−1 for λ-cyhalothrin and acetamiprid, respectively. The analysis times were 15 and 20 min, with retention times of 2.35 and 7.94 min for λ-cyhalothrin and acetamiprid, respectively. Results reveal that most of the surveyed farmers were not educated (70% < Primary School Certificate) and were men (95%). Of the main insecticides applied by farmers, λ-cyhalothrin and acetamiprid were found to be the most technical-grade ones. Furthermore, the analysis of insecticides showed that the concentrations obtained in our study often differed from the ones mentioned on insecticide labels. The proposed method is useful for quantifying insecticides in various technical and commercial formulations with little interference from additives.

Agrochemicals doi: 10.3390/agrochemicals2040030

Authors: Patrice A. Marchand

Biocontrol agent (BCA) plant protection active substances composed from microorganisms, semiochemicals and substances from natural origins are increasing in Europe, since their entry into force of Regulation (EC) 1107/2009, in number and as a percentage of total active substances. As they are included in the scope of plant protection products (PPPs), this raises the question as to whether they are only substitute active substances, more socially acceptable, sustainable and environmentally preferable, or really another way of managing bioaggressors, pests and diseases. As we have conducted a survey of all active substances listed in all Parts of Regulation EU 540/2011 and compared chemical to BCA active substances, described their evolution and characteristics since 2011 and predicted the global perspective in the future years for both chemical, which are in decline, and BCA AS separately, these works raised the question of whether these BCA AS are a substitution, as is often the case for users, for the previous chemical AS, or whether they are fundamentally different new substances, which clearly obey a new vision of crop protection. This study therefore encompasses all active substances approved at any time in Europe since 2011 for both categories, whether still approved or not. At the end of this assessment, the following conclusion can be drawn: BCA AS are mainly fundamentally different substances from chemical AS, in all the compartments studied. A comparison between BCAs and chemical active substances allowed under (EC) 1107/2009 PPP Regulation is described together with a characterisation of BCA AS listed in EC 540/2011 PPP Regulation. Finally, the specific distinction of BCA vs. chemical active substance profile is analysed. This work allows us to conclude on the evolution of crop protection and the means that must be implemented to face current and new threats.

Agrochemicals doi: 10.3390/agrochemicals2040029

Authors: Alberto Camas-Reyes Andrés A. Estrada-Luna José de Jesús Ponce-Ramírez María Karina Manzo-Valencia Francisco Galván-Pantoja Martha Edith Moreno-Valencia Ana Lilia Hernández-Orihuela José Arbel Santiago-Díaz Silvia Valdés-Rodríguez Agustino Martínez-Antonio

The global demand for sustainable agricultural practices is increasing, necessitating the preference for fertilizers and organic stimulants with minimal chemical transformation. This study investigates the potential use of Mucuna (Mucuna pruriens sp.) and avocado (Persea americana Mills) seed residues in the cultivation of cherry-tomato crops (Lycopersicon esculentum Mill.) var. cerasiforme. After extracting L-dopa, the Mucuna ground residual seeds were incorporated into the soil substrate as an edaphic fertilizer. In contrast, the hydrolyzed avocado seed was mixed with water or the nutrient Long Ashton and applied as a foliar biostimulant to cherry plants grown in a greenhouse. We report the nutrients and amino acid content in hydrolysates of the avocado and Mucuna’s residue seeds and experiment with their effect in plants employing a completely blocked random design of eight treatments with four replicates. Data inspection involved analysis of variance, and mean differences were determined using Fisher’s least significant difference test. Significant differences (p < 0.05) were observed among the treatments regarding the number of flowers (70%), fruits (23%), and dry weight fruits (25%) in favor of those using these seed residues. A second experiment revealed that treatments containing both seed residues slightly increased the °Brix in fruits. This study supports with evidence that residual seeds benefit tomatoes and probably other important plants, contributing to the path to sustainable agriculture.

Agrochemicals doi: 10.3390/agrochemicals2040028

Authors: Rachel A. Fenn Davie M. Kadyampakeni Ramdas G. Kanissery Jonathan Judy Mahesh Bashyal

The unintended loss of glyphosate and P from cropland may pose an environmental risk to downstream water quality and marine ecosystems. Glyphosate and P compete for exchange sites, and since glyphosate is an organophosphate, it reacts similarly to phosphates in soil. The competition for exchange sites between glyphosate and P could lead to an increased risk of loss due to leaching, leading to water quality degradation and harm to aquatic wildlife. The focus of this study was to (i) determine the sorption tendencies of P and orthophosphate in Florida Entisols and (ii) determine the sorption tendencies of glyphosate in Florida Entisols. Adsorption and desorption experiments were performed for both P and glyphosate. The data from the sorption experiments were fitted to linear, Freundlich, and Langmuir models. Orthophosphate-P (ortho-P) was best represented by the linear isotherm. Glyphosate adsorption was best represented by the linear isotherm, and desorption was best represented by both the linear and Freundlich models. Phosphorus and glyphosate sorption and desorption increased with soil depth, likely due to the higher concentrations of Fe and Al with greater depth. These results could improve P and glyphosate application rates when applied in tandem to citrus trees, increasing overall tree health and improving soil quality.

Agrochemicals doi: 10.3390/agrochemicals2040027

Authors: Konstantinos B. Simoglou Paraskevi El. Skarpa Emmanouil Roditakis

Greek consumers perceive an increased risk of pesticide residues in food. This study examined Greek consumers’ perceptions of the safety of Greek plant-based food compared to those from other EU countries. One-half of Greek consumers believe Greek food is as safe as other European foods, while the other half disagree. According to a principal component analysis and a bivariate logistic regression, several factors, such as the perceived safety of plant foods, education, age, gender, traceability, perceived benefits and risks of pesticides, actual pesticide use, and authoritative information sources, influence this attitude. Authoritative knowledge in this field can reduce risk perception and improve Greek consumers’ attitudes towards food safety. The latent class analysis identified two categories of consumers. The first class receives limited information about pesticides, leading to lower perceived pesticide benefits, higher mistrust of traceability, and concerns about pesticide residues. In contrast, the second class actively searches for information from credible sources, endorses the Greek plant foods safety, acknowledges the pesticide benefits, and trusts traceability. Official information is associated with reduced risk perception. Regulators should consider the impact of sociodemographic and other intrinsic characteristics on individuals’ risk perceptions and prioritise transparency in risk communication strategies.

Agrochemicals doi: 10.3390/agrochemicals2030026

Authors: Árpád Ambrus Júlia Szenczi-Cseh Lajos Bíró Adrienn Vásárhelyi Henriett Szemánné Dobrik

The short-term intake (ESTI) of pesticide residues in Hungarian consumers was assessed based on 2331 test results obtained during the 2017–2021 monitoring program on frequently analyzed apples, sour cherries, table grapes, peaches, nectarines, peppers, and strawberries (23.5% of all samples taken from 119 crops). The age-specific consumption data were obtained from national food consumption surveys (2009 and 2018–2020). The exposure was characterized by Hazard Quotient and Hazard Index considering the acute reference doses of pesticide residues detected in the samples. When ESTI was calculated with all detected “single” residues and a variability factor of 3.6, recommended for evaluation of monitoring results, the HI only exceeded 1 for children <3 years old eating grapes (1.50–1.81). HI was <1 when any of the six foods were eaten together within one day. Between forty and fifty percent of samples contained 2–23 residues. Though the individual residue concentrations were below the corresponding MRLs, multiple residues being present in one sample resulted in maximum HI values in apples (1.14); grapes (6.57); peaches and nectarines (2.57); strawberries (2.74); and peppers (10.44). Residues with low ARfD values contributed the most. Applying HI is simple, but provides only point estimates; therefore, it should only be used in first-tier risk assessment.

Agrochemicals doi: 10.3390/agrochemicals2030025

Authors: Patrice A. Marchand

Neonicotinoid (NN) insecticides derived from natural insecticide nicotine are EU chemical crop protection systemic active substances that are controversial regarding their toxicity and ecotoxicity, especially versus pollinators and birds. Clearly, the last European evaluation by the European Food Safety Authority exhibited a danger to wild and managed bees. Concomitantly, the decline in birds was partially attributed to this class of substances, which constitutes a family in itself, both in Europe and the USA. At the regulatory level, following the initial approval waves in 2011 and 2019, and mainly taking into account these ecotoxicological considerations, the commission banned the use of three NN insecticides in 2013 (imidacloprid, clothianidin, and thiamethoxam), and later, only one NN (acetamiprid) was renewed. Four NN approvals were removed by the end of approval or non-renewal in 2019 and 2020, and two are currently concerns for renewals in 2025, even if extensions of the approval durations of these NNs are to be expected due to the current slowness of the renewal procedure. Therefore, from the total number (17) of NN insecticide molecules known all over the world, up to seven NN were approved by the EU plant protection Regulation EC 1107/2009 between 2011 and now. All of these active substances are listed in Parts A and B of Regulation EU 540/2011 managing active substances. The regulatory evolution of these agrochemicals is analysed in this work, from the corresponding global modifications in terms of the number of active substances, employment, functions, uses covered, protected crops, and maximum residue limits. We also analysed their ability to persist as an agrochemical family and the potential of the inclusion of new NN members together with their current restrictions during their active substance life in Europe.

Agrochemicals doi: 10.3390/agrochemicals2030024

Authors: Panagiotis Kanatas Vasilis Ntaoulis Ioannis Gazoulis Athanasios Andreou Marios Danaskos Dimitrios Mpounanos Eleni-Anna Karanika Panayiota Papastylianou Ilias Travlos

Horseweed (C. canadensis) and fleabane (C. sumatrensis) are two annual or perennial herbaceous weeds present with high frequency and density in many parts of the world. Their response to water deficit was studied by means of seed germination tests and pot experiments. Seed germination was tested in solutions with different concentrations of polyethylene glycol (PEG). Two biotypes of each species were examined, one glyphosate resistant and the other susceptible. Growth responses were similar in the two species, both being more affected by lower (−1 MPa) than higher water potential (−0.2 MPa). The results revealed a significant effect of the biotype and the weed species on the drought stress response and adaptation. When high PEG concentrations were applied (−0.6 MPa), both C. sumatrensis biotypes had higher germination percentages (up to 88%) than the C. canadensis biotypes, while in most cases the seeds of the resistant biotypes germinated more (up to 72%) compared to the susceptible ones. These findings were confirmed by means of NDVI values, indicating that remote sensing can be used for a quick evaluation of the drought stress response of these weeds. The results obtained highlight the significant effect of species, biotypes and drought stress level on the germination, survival and growth of the weeds.

Agrochemicals doi: 10.3390/agrochemicals2030023

Authors: Árpád Ambrus Adrienn Vásárhelyi Géza Ripka Henriett Szemánné-Dobrik Júlia Szenczi-Cseh

As mandated by the EU and the national risk management duties, pesticide residues were determined by four specialized laboratories in 9924 samples taken from 119 crops of economic importance in Hungary and imported foodstuffs during 2017–2021. The screening method applied covered 622 pesticide residues as defined for enforcement purposes. The limit of detection ranged between 0.002 and 0.008 mg/kg. The 1.0% violation rate concerning all commodities was lower than in the European Union. No residue was detectable in 45.9% of the samples. For detailed analyses, six commodities (apple, cherry, grape, nectarine/peach, sweet peppers, and strawberry) were selected as they were analyzed in over 195 samples and most frequently contained residues. Besides testing their conformity with national MRLs, applying 0.3 MRL action limits for pre-export control, we found that 73% of the sampled lots would be compliant with ≥90% probability based on a second independent sampling. Multiple residues (2–23) in one sample were detected in 36–50% of the tested lots. Considering the provisions of integrated pest management, and the major pests and diseases of selected crops, normally three to four and exceptionally, seven to nine active ingredients with different modes of action should suffice for their effective and economic protection within four weeks before harvest.

Agrochemicals doi: 10.3390/agrochemicals2030022

Authors: Becky Talyn Kelly Muller Cindy Mercado Bryan Gonzalez Katherine Bartels

Use of glyphosate and glyphosate-based herbicides is ubiquitous in US agriculture and widespread around the world. Despite marketing efforts to the contrary, numerous studies demonstrate glyphosate toxicity to non-target organisms including animals, primarily focusing on mortality, carcinogenicity, renal toxicity, reproductive, and neurological toxicity, and the biochemical mechanisms underlying these physiological outcomes. Glyphosate toxicity also impacts animal behavior, both in model systems and in agricultural and environmentally relevant contexts. In this review, we examine the effects of glyphosate and glyphosate-based herbicides on animal behaviors, particularly activity, foraging and feeding, anti-predator behavior, reproductive behaviors, learning and memory, and social behaviors. Glyphosate can be detected both in food and in the environment, and avoided through activity and feeding strategies. However, exposure also reduces activity, depresses foraging and feeding, increases susceptibility to predation, interferes with courtship, mating, fertility and maternal behaviors, decreases learning and memory capabilities, and disrupts social behaviors. Changes in animal behavior as a result of glyphosate toxicity are important because of their sometimes severe effects on individual fitness, as well as ecosystem health. Implications for human behavior are also considered.

Agrochemicals doi: 10.3390/agrochemicals2030021

Authors: Ivan A. Yaremenko Peter S. Radulov Yulia Yu. Belyakova Dmitrii I. Fomenkov Vera A. Vil’ Maria A. Kuznetsova Valentina N. Demidova Alexei P. Glinushkin Alexander O. Terent’ev

The search for new classes of fungicides has long been important in plant protection due to the development of fungal resistance to currently used agrochemicals. Organic peroxides have long been regarded as exotic and unstable compounds. The discovery of the antimalarial activity of the peroxide natural product Artemisinin, an achievement that was recently recognized with the Nobel Prize, has brought organic peroxides into the medicinal and agrochemistry. In this paper, fungicidal activity of synthesized organic peroxides—geminal bishydroperoxide, bridged 1,2,4,5-tetraoxanes, and tricyclic monoperoxides—were tested in vitro against an important species of phytopathogenic fungi (F. culmorum, R. solani, A. solani, P. infestans, C. coccodes). We discovered that substituted bridged 1,2,4,5-tetraoxanes exhibit fungicidal activity comparable or superior to azoxystrobin and superior to geminal bishydroperoxide and tricyclic monoperoxides. The contact mode of action was demonstrated for the bridged 1,2,4,5-tetraoxane.

Agrochemicals doi: 10.3390/agrochemicals2020020

Authors: Marcela C. Pagano Matthew Kyriakides Thom W. Kuyper

Substantial amounts of pesticides, used in agricultural production to control pests, diseases, and weeds, and thereby attain high product quantities and quality, can severely affect the ecosystem and human health. The amounts of pesticides used depend on the specifics of the current production system but also exhibit large effects of past practices. Pesticides do not act only on the target organisms but also on organisms for which the chemicals were not specifically formulated, constituting hazardous molecules for humans and the environment. Pesticides, therefore, also influence soil microbial communities including organisms that engage in mutualistic plant symbioses that play a crucial role in its mineral nutrition, such as arbuscular mycorrhizal fungi. In this review, we summarize the current knowledge on the effects of synthetic and natural (‘green’) pesticides (fungicides, herbicides, and insecticides) on arbuscular mycorrhizal symbiosis. We deal with both the direct effects (spore germination and extraradical and intraradical growth of the mycelium) and indirect effects on the agroecosystem level. Such indirect effects include effects through the spread of herbicide-resistant crops and weeds to neighboring ecosystems, thereby modifying the mycorrhizal inoculum potential and altering the plant–plant interactions. We also briefly discuss the possibility that mycorrhizal plants can be used to enhance the phytoremediation of organic pesticides.

Agrochemicals doi: 10.3390/agrochemicals2020019

Authors: Anurag Yadav Kusum Yadav Kamel Abd-Elsalam

In an alarming tale of agricultural excess, the relentless overuse of chemical fertilizers in modern farming methods have wreaked havoc on the once-fertile soil, mercilessly depleting its vital nutrients while inflicting irreparable harm on the delicate balance of the surrounding ecosystem. The excessive use of such fertilizers leaves residue on agricultural products, pollutes the environment, upsets agrarian ecosystems, and lowers soil quality. Furthermore, a significant proportion of the nutrient content, including nitrogen, phosphorus, and potassium, is lost from the soil (50–70%) before being utilized. Nanofertilizers, on the other hand, use nanoparticles to control the release of nutrients, making them more efficient and cost-effective than traditional fertilizers. Nanofertilizers comprise one or more plant nutrients within nanoparticles where at least 50% of the particles are smaller than 100 nanometers. Carbon nanotubes, graphene, and quantum dots are some examples of the types of nanomaterials used in the production of nanofertilizers. Nanofertilizers are a new generation of fertilizers that utilize advanced nanotechnology to provide an efficient and sustainable method of fertilizing crops. They are designed to deliver plant nutrients in a controlled manner, ensuring that the nutrients are gradually released over an extended period, thus providing a steady supply of essential elements to the plants. The controlled-release system is more efficient than traditional fertilizers, as it reduces the need for frequent application and the amount of fertilizer. These nanomaterials have a high surface area-to-volume ratio, making them ideal for holding and releasing nutrients. Naturally occurring nanoparticles are found in various sources, including volcanic ash, ocean, and biological matter such as viruses and dust. However, regarding large-scale production, relying solely on naturally occurring nanoparticles may not be sufficient or practical. In agriculture, nanotechnology has been primarily used to increase crop production while minimizing losses and activating plant defense mechanisms against pests, insects, and other environmental challenges. Furthermore, nanofertilizers can reduce runoff and nutrient leaching into the environment, improving environmental sustainability. They can also improve fertilizer use efficiency, leading to higher crop yields and reducing the overall cost of fertilizer application. Nanofertilizers are especially beneficial in areas where traditional fertilizers are inefficient or ineffective. Nanofertilizers can provide a more efficient and cost-effective way to fertilize crops while reducing the environmental impact of fertilizer application. They are the product of promising new technology that can help to meet the increasing demand for food and improve agricultural sustainability. Currently, nanofertilizers face limitations, including higher costs of production and potential environmental and safety concerns due to the use of nanomaterials, while further research is needed to fully understand their long-term effects on soil health, crop growth, and the environment.

Agrochemicals doi: 10.3390/agrochemicals2020018

Authors: Laura T. Ward Michelle L. Hladik Aidee Guzman Ariana Bautista Nicholas J. Mills

Neonicotinoid seed treatments are commonly used in agricultural production even though their benefit to crop yield and their impact on pollinators, particularly wild bees, remains unclear. Using an on-farm matched pair design in which half of each field was sown with thiamethoxam treated seed and half without, we assessed honey bee and wild bee exposure to pesticides in sunflower fields by analyzing pesticide residues in field soil, sunflower pollen and nectar, pollen-foraging and nectar-foraging honey bees, and a sunflower specialist wild bee (Melissodes agilis). We also quantified the effects of thiamethoxam-treated seed on wild bee biodiversity and crop yield. M. agilis abundance was significantly lower with thiamethoxam treatment and overall wild bee abundance trending lower but was not significantly different. Furthermore, crop yield was significantly lower in plots with thiamethoxam treatment, even though thiamethoxam was only detected at low concentrations in one soil sample (and its primary metabolite, clothianidin, was never detected). Conversely, wild bee richness was significantly higher and diversity was marginally higher with thiamethoxam treatment. Nectar volumes harvested from the nectar-foraging honey bees were also significantly higher with thiamethoxam treatment. Several pesticides that were not used in the sunflower fields were detected in our samples, some of which are known to be deleterious to bee health, highlighting the importance of the landscape scale in the assessment of pesticide exposure for bees. Overall, our results suggest that thiamethoxam seed treatments may negatively impact wild bee pollination services in sunflower. Importantly, this study highlights the advantages of the inclusion of other metrics, such as biodiversity or behavior, in pesticide risk analysis, as pesticide residue analysis, as an independent metric, may erroneously miss the impacts of field realistic pesticide exposure on bees.

Agrochemicals doi: 10.3390/agrochemicals2020017

Authors: Aniket Gade Pramod Ingle Utkarsha Nimbalkar Mahendra Rai Rajesh Raut Mahesh Vedpathak Pratik Jagtap Kamel A. Abd-Elsalam

The microflora of the soil is adversely affected by chemical fertilizers. Excessive use of chemical fertilizers has increased crop yield dramatically at the cost of soil vigor. The pH of the soil is temporarily changed by chemical fertilizers, which kill the beneficial soil microflora and can cause absorption stress on crop plants. This leads to higher dosages during the application, causing groundwater leaching and environmental toxicity. Nanofertilizers (NFs) reduce the quantity of fertilizer needed in agriculture, enhance nutrient uptake efficiency, and decrease fertilizer loss due to runoff and leaching. Moreover, NFs can be used for soil or foliar applications and have shown promising results in a variety of plant species. The main constituents of nanomaterials are micro- and macronutrient precursors and their properties at the nanoscale. Innovative approaches to their application as a growth promoter for crops, their modes of application, and the mechanism of absorption in plant tissues are reviewed in this article. In addition, the review analyzes potential shortcomings and future considerations for the commercial agricultural application of NFs.

Agrochemicals doi: 10.3390/agrochemicals2020016

Authors: Anurag Yadav Kusum Yadav Rumana Ahmad Kamel Abd-Elsalam

This review article provides an extensive overview of the emerging frontiers of nanotechnology in precision agriculture, highlighting recent advancements, hurdles, and prospects. The benefits of nanotechnology in this field include the development of advanced nanomaterials for enhanced seed germination and micronutrient supply, along with the alleviation of biotic and abiotic stress. Further, nanotechnology-based fertilizers and pesticides can be delivered in lower dosages, which reduces environmental impacts and human health hazards. Another significant advantage lies in introducing cutting-edge nanodiagnostic systems and nanobiosensors that monitor soil quality parameters, plant diseases, and stress, all of which are critical for precision agriculture. Additionally, this technology has demonstrated potential in reducing agro-waste, synthesizing high-value products, and using methods and devices for tagging, monitoring, and tracking agroproducts. Alongside these developments, cloud computing and smartphone-based biosensors have emerged as crucial data collection and analysis tools. Finally, this review delves into the economic, legal, social, and risk implications of nanotechnology in agriculture, which must be thoroughly examined for the technology’s widespread adoption.

Agrochemicals doi: 10.3390/agrochemicals2020015

Authors: Alexander S. Lukatkin Anastasia S. Sokolova Andrey A. Lukatkin Ilya A. Cherepanov Natalia V. Kalganova Sergey K. Moiseev

An increase in the yield of the main cereal crops in the context of global climate changes requires additional impacts on plants. Natural and synthetic plant growth regulators (PGRs) are used to increase plant productivity and reduce the injury level caused by abiotic stressors. There is a growing need for novel highly effective plant growth stimulants to exhibit their effects at low doses and to not pose an environmental threat or injury to the crop quality. The derivatives of sydnone imine (SI), a mesoionic heterocycle possessing a 1,2,3-oxadiazole core, have been used as medicines until now but have not been used for agricultural applications. Some SI derivatives have recently been found to exhibit PGR properties. Herein, we report on the study of the PGR potential of nine SI derivatives bearing variable substituents at N(3), C(4), and N6 positions of the heterocycle designed to disclose the “molecular structure-PGR activity” relationship in this family. The SI derivatives were used in a wide concentration range (10−9–10−4 mol/L) for a pre-sowing treatment of winter wheat (Triticum aestivum L., two cultivars) and maize (Zea mays L., two hybrids) seeds in germinating experiments. All compounds were found to affect the growth of the axial organs of germinants, with the growth-stimulating or -inhibitory effect as well as its rate being considerably different for wheat and maize and, in many cases, also for roots and shoots. In addition, a pronounced concentration dependence of the effect was disclosed for many cases. The features of the molecular structure of SIs affecting their growth-regulating properties were elucidated. Compounds 4, 6, 7, and 8, which had exhibited a growth-promoting effect in germinating experiments, were used at appropriate concentrations for pot experiments on the same crops. For all compounds, the experiments showed a stimulating effect on the growth of roots (up to 80%), shoots (up to 112%), leaf area (up to 113%), fresh weights of roots (up to 83%), and aerial parts of the plants (up to 87%) or only on some of these parameters. The obtained results show a healthy outlook for the use of SI derivatives as promoting agents for improving the growth of cereal crop plants.

Agrochemicals doi: 10.3390/agrochemicals2020014

Authors: Elielton Germano dos Santos Miriam Hiroko Inoue Ana Carolina Dias Guimarães Jennifer Stefany Queiroz Bastos Ricardo Alcántara-de la Cruz Kassio Ferreira Mendes

The presence of weeds in the sunflower crop is one of the main factors linked to the low increase in productivity of this crop, and to determine the most appropriate management of weeds, it is essential to carry out a diagnosis through the phytosociological survey. The objective of this study was to assess the influence of chemical control on the phytosociological community of weeds in three areas cultivated with sunflower in the Parecis region (Brazil). The areas were treated with 2,4-D + glyphosate for desiccation; S-metolachlor was used for pre-emergence control in the three areas; meanwhile, sulfentrazone and flumioxazin were applied only in one area; and, finally, clethodim was applied for post-emergence weed management. Sampling was carried out at two different times, in the initial and pre-harvest stages (at 35 and 100 days after the emergence of the crop, respectively), using a quadrate, in which weeds were identified and quantified to determine the frequency, relative frequency, density, relative density, abundance, relative abundance, importance index, and similarity index between areas and times. Seventeen weed species were found in the sunflower crop (70.6% dicot and 29.4% monocotyledonous) in the two seasons, grouped into nine botanical families, with Poaceae being the most diverse family. The dicots Tridax procumbens and Acanthospermum hispidium were present in low frequency only in the initial stages of development of the sunflower crop. The weeds with the highest importance index values in the initial and pre-harvest stages were Euphorbia hirta (104 and 91%) and Bidens pilosa (45 and 66%, respectively), both belonging to the dicots group. These two species were present in the two evaluated periods and in the three experimental areas, demonstrating that there was a similarity index between them with values above 93%. These results of the phytosociological study may contribute to determining more efficient management strategies for weed chemical control in the sunflower crop.

Agrochemicals doi: 10.3390/agrochemicals2020013

Authors: Nour Yousry Paige Henderson Jordanna Sprayberry

Bumblebees are valuable generalist pollinators. However, micro- and macro-stressors on bumblebees negatively impact both foraging efficiency and pollination efficacy. Given that colonies have a resource threshold for successful reproduction, factors that decrease foraging efficiency could negatively impact conservation efforts. Recently, agrochemical odor pollution has been shown to hinder floral odor learning and recognition in Bombus impatiens via an associative odor learning assay (FMPER). These results may have implications for the field foraging behavior of bumblebees. Building on this prior work, our study aimed to determine if negative effects of fungicides on associative odor learning and recognition scale up to negative impacts on actively foraging bumblebees. These experiments investigated whether the presence of a background fungicide odor (Reliant® Systemic Fungicide) impacts the location of a learned floral resource (lily of the valley-scented blue flowers) in a wind tunnel. Experiments were run with and without early access to visual cues to determine if fungicide odor pollution is more impactful on bees that are engaged in olfactory versus visual navigation. Fungicide odor pollution reduced landing frequency in both paradigms.

Agrochemicals doi: 10.3390/agrochemicals2020012

Authors: Muhammad M. Mukhtar Muhammad A. Mustapha Mubarak Aliyu Sulaiman S. Ibrahim

There is a severe lack of information about molecular mechanisms of pesticide resistance in the rust-red flour beetle, a major pest destroying grains and flour across Nigeria, hindering evidence-based control. Here, we identified to the species level three populations of the red flour beetle from Kano, Nigeria, as Tribolium castaneum (Herbst 1797) and investigated the mechanism driving their insecticide resistance. The IRAC susceptibility bioassays established cypermethrin resistance, with LC50s of 4.35–5.46 mg/mL in the three populations, NNFM, R/Zaki and Yankaba. DDT and malathion resistance were observed in NNFM, with LC50s of 15.32 mg/mL and 3.71 mg/mL, respectively. High susceptibility was observed towards dichlorvos in all three populations with LC50s of 0.17–0.35 mg/mL. The synergist bioassay with piperonylbutoxide significantly restored cypermethrin susceptibility, with mortality increasing almost threefold, from 24.8% obtained with 1.5 mg/mL of cypermethrin to 63.3% in the synergised group (p = 0.013), suggesting a preeminent role of P450s. The two major knockdown resistance (kdr) mutations, T929I and L1014F, in the IIS4 and IIS6 fragments of the voltage-gated sodium channel were not detected in both cypermethrin-alive and cypermethrin-dead beetles, suggesting a lesser role of target-site insensitivity mechanisms. These findings highlight the need to explore alternative control tools for this pest and/or utilise synergists, such as piperonyl butoxide, as additional chemistries in pesticide formulations to improve their efficacy.

Agrochemicals doi: 10.3390/agrochemicals2010011

Authors: Bruna Aparecida de Paula Medeiros Maura Gabriela da Silva Brochado Guilherme Augusto de Paiva Ferreira Alessandro da Costa Lima Kamila Cabral Mielke Kassio Ferreira Mendes

Tomatoes are often grown in proximity to other crops such as grain, which can increase their susceptibility to herbicide drift and subsequent crop. Therefore, the objective of this study was to evaluate the effect of simulated herbicide drift on tomato plants. Treatments were established in a 10 × 3 + 1 factorial scheme using a completely randomized design with four replications. The first factor consisted of ten herbicides, while the second was composed by three subdoses (1/4, 1/16, and 1/32) along with an additional treatment without herbicide application. The herbicides 2,4-D, dicamba, glyphosate, saflufenacil, oxyfluorfen, and isoxaflutole caused injury levels greater than 20% or reductions in plant biomass greater than 30% at the lowest subdose. Increasing the subdose resulted in a corresponding increase in injury level and a reduction in biomass. Tomato exposed to hexazinone, diuron, nicosulfuron, and diquat at a subdose of 1/64 exhibited low injury levels and biomass reductions. However, at other subdoses, these herbicides caused significant plant damage. Among the herbicides tested, the auxinic herbicides, particularly dicamba, presented a higher risk for the tomato crop. The documentation and description of the visual symptoms caused by each herbicide applied to tomatoes will aid producers to identify drift problems in the field.

Agrochemicals doi: 10.3390/agrochemicals2010010

Authors: Yusuf Andriana Nabila Ayunisa Fajriani Ade Chandra Iwansyah Tran Dang Xuan

Adlay (Coix lacryma-jobi L.) is a cereal crop that has traditionally been used for medicinal purposes. It is processed into nutritious food in China and Southeast Asian countries. This study assesses the phytochemical constituents of this plant and their potential as antioxidants and crop protection agents. The methanolic extracts from seeds of Indonesian adlay (C. lacryma-jobi) varieties including Agrotis, Ma-yuen, and Aquatic, were tested against 2,2-diphnyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) to determine their free radical scavenging activity. The relationship between extraction solvents, phytochemical composition, and antioxidant activity was analyzed statistically using principal component analysis (PCA) to classify them based on the similarities among the components. The potential use of the phytochemicals as crop protection agents was also explored through a review of the literature. The Agrotis variety demonstrated the highest antioxidant activities (IC50 DPPH = 741.49 and ABTS =152.69 µg/mL). The ethyl acetate fraction of this variety showed the greatest antioxidant activity (IC50 DPPH and ABTS = 106.34 and 17.62 µg/mL, respectively), total phenolic content (275.16 mg GAE/g extract), and flavonoid content (37.41 mg QE/g extract). Fatty acids (FAs) and fatty acid methyl esters (FAMEs) accounted for 47.71 ± 0.02 and 41.73 ± 0.04%, respectively, and they were the major components of the extracts. The principal component analysis (PCA) revealed three different groups of phytochemical components in the seeds of Agrotis variety, including fatty acid methyl esters (FAMEs), such as methyl linoleate, methyl stearate, methyl vaccinates, and methyl palmitate, and fatty acids (FAs), including 7-hexadecanoid acid, bovinic acid, and 15-hydroxipentadecanoic acid. The final phytochemical group consisted of minor components, including uncategorized compounds such as decamethyl-tetrasiloxane and cycloalkenes. This study highlights the fact that C. lacrima-jobi is a promising source of natural antioxidants and agrochemicals.

Agrochemicals doi: 10.3390/agrochemicals2010009

Authors: Preeti Bairwa Nimish Kumar Vijay Devra Kamel Abd-Elsalam

Green chemistry and nanobiotechnology have great potential for generating new and significant products that are favorable to the environment, industry, and consumers. The nanoforms of metals and nanocomposites are more effective and efficient agents than their bulkier counterparts because of their distinctive physical, chemical, and optical properties. Green technology is a rapidly growing scientific field that has recently received attention due to its many applications. Different nanoparticle dimensions, sizes, and bioactivities will develop as a consequence of changes in the biomaterials employed for synthesis. The existing understanding of several green synthesis methods, that depend on different plant components and microorganisms for the production of nanoparticles, is summarized in the current review. Employing these materials minimizes synthesis costs while minimizing the use of hazardous chemicals and promoting “biosynthesis.” To produce metal nanoparticles efficiently, bio-reduction is influenced by the abundance of essential enzymes, proteins, and biomolecules. Rapid biosynthetic regeneration makes this characteristic sufficient for their employment in a range of situations. In this review, we explore the biosynthesis of nanomaterials and their potential in sustainable agriculture. Biosynthesized nanofertilizers, or bionanofertilizers, are a revolutionary new class of fertilizer that has been developed with the help of nanotechnology. These fertilizers offer many advantages over traditional fertilization methods and can be used to increase crop yields while reducing the environmental impact of fertilizers. Bionanofertilizer are an inexpensive way to increase plant growth and production, and to improve the use of nutrients by plants and the health of the soil. According to our survey, nanotechnology presents a wide range of prospects by offering a cutting-edge and environmentally friendly alternative in the agricultural sector.

Agrochemicals doi: 10.3390/agrochemicals2010008

Authors: Patrice A. Marchand

Agrochemicals are synthetic or hemi-synthetic crop protection substances which are supervised by the EU Regulation EC 1107/2009, which give rise to plant protection products (PPP) with market authorizations. Most of these active substances of chemical origin were transferred from the previous Annex I of Directive 91/414/EEC to Part A of Regulation EU 540/2011, with newly approved active substances mainly being listed in Part B or E, while renewed substances were moved from Part A to Part B or E. In this study, approved agrochemicals from the early part of 2023 are organized into categories, families, functions, usages, treated crop categories, regulatory characteristics, and maximum residue limits (MRLs). Perspectives regarding their evolution are also described together with pending approvals.

Agrochemicals doi: 10.3390/agrochemicals2010007

Authors: Kifayatullah Kakar Tran Dang Xuan Tran Dang Khanh

This study determined the influence of cattle manure compost, chemical fertilizers, and mulch on the growth of weeds, sugar content, and growth of sweet sorghum (Sorghum bicolor (L.) Moench). The inhibitory potential of root exudates from two sweet sorghum cultivars (A; K1151 and B; K3351) was also evaluated. Chemical fertilizers increased the plant height, stem weight, biomass production, and sugar content of sweet sorghum. The total phenolic contents in the root exudates were 22.93 mg gallic acid equivalent per g dry weight (GAE/g DW) for cultivar A and 15.66 mg GAE/g DW for cultivar B. The total flavonoid contents in the root exudates were 14.77 mg rutin equivalent per g dry weight (RE/g DW) for cultivar A and 12.44 mg RE/g DW for cultivar B. The leaf extracts contained a higher amount of total phenolics and flavonoids than that of the stem and root. The inhibitory level of the root exudates from cultivar A on the seed germination and shoot growth of lettuce was greater than for cultivar B. Six phenolic acids, including protocatechuic, p-hydroxybenzoic, syringic, sinapic, p-coumaric, and benzoic acids, were detected from root exudates, root, stem, and leaf of both cultivars. The amount of p-coumaric acid in root exudates was greater than the other plant parts; however, protocatechuic acid was only found in the root exudates. p-Coumaric and protocatechuic acids may play an important role in the allelopathy of sweet sorghum to help reduce the dependence on synthetic herbicides in agricultural practice. This study indicates that cultivation methods and fertilization are important to increase both agronomic and economic values of sweet sorghum in agricultural production.

Agrochemicals doi: 10.3390/agrochemicals2010006

Authors: Árpád Ambrus Júlia Szenczi-Cseh Vy Vy N. Doan Adrienn Vásárhelyi

Pesticide residue monitoring data reflect the actual residues in foods as traded and are suitable for estimating consumers’ exposure, evaluating compliance with maximum residue limits, MRLs, and refining future risk-based sampling programmes. The long-term exposure (daily intake) is calculated from the national or regional food consumption data and average residues in the edible portions of food. The non-detected residues may be counted as LOQ, 0.5 LOQ, or 0. The short-term intake is calculated from the large portion consumption of individual foods multiplied by the highest residue concentration found in them and the relevant variability factor. Dietary exposure to a pesticide residue may be characterised by the hazard quotient (HQ) and the hazard index (HI). Cumulative exposure should only be assessed for those compounds having the common mechanism of toxicity (cumulative assessment group, CAG). The number of residue data required for these assessments should be calculated with distribution-free statistics at the targeted confidence level. The proper evaluation of the numerous results can only be completed if they are electronically recorded and can be retrieved in specific formats. Our objectives are to present methods for consumer risk assessment, testing compliance with MRLs, and ranking commodities for risk-based sampling and to give examples of electronic processing of residue data.

Agrochemicals doi: 10.3390/agrochemicals2010005

Authors: Charles Benbrook Robin Mesnage William Sawyer

Controversy over the oncogenicity of glyphosate-based herbicides (GBHs) persists seven years after a 2015 IARC Monograph classified glyphosate/GBHs as “probably carcinogenic” to humans. Most regulatory authorities have concluded that technical glyphosate poses little or no oncogenic risk via dietary exposure. The US EPA classified glyphosate as “not likely” to pose cancer risk in 1991, a decision reaffirmed in reports issued in 2017 and 2020. A Federal Circuit Court of Appeals in the US vacated EPA’s assessment of glyphosate human-health risks in 2022 and required EPA to revisit old and take into account new data in its forthcoming, possibly final glyphosate/GBH reregistration decision. Divergent assessments of GBH genotoxicity are the primary reason for differing conclusions regarding GBH oncogenic potential. We assessed whether assays published since completion of the EPA and IARC reviews shed new light on glyphosate/GBH genotoxicity. We found 94 such assays, 33 testing technical glyphosate (73% positive) and 61 on GBHs (95% positive). Seven of 7 in vivo human studies report positive results. In light of genotoxicity results published since 2015, the conclusion that GBHs pose no risk of cancer via a genotoxic mechanism is untenable.

Agrochemicals doi: 10.3390/agrochemicals2010004

Authors: Elena R. Lopat’eva Alexander S. Budnikov Igor B. Krylov Anna L. Alekseenko Alexey I. Ilovaisky Alexey P. Glinushkin Alexander O. Terent’ev

The search for fungicides of novel classes is the long-standing priority in crop protection due to the continuous development of fungal resistance against currently used types of active compounds. Recently, 4-nitropyrazolin-3-ones were discovered as highly potent fungicides, of which activity was believed to be strongly associated with the presence of a nitro group in the pyrazolone ring. In this paper, a series of 4-substituted pyrazolin-3-ones were synthesized and their fungicidal activity against an important species of phytopathogenic fungi (Venturia inaequalis, Rhizoctonia solani, Fusarium oxysporum, Fusarium moniliforme, Bipolaris sorokiniana, and Sclerotinia sclerotiorum) was tested in vitro. We discovered that 4-mono and 4,4-dihalogenated pyrazolin-3-ones demonstrate fungicidal activity comparable to that of 4-nitropyrazolin-3-ones and other modern fungicides (such as kresoxim methyl). This discovery indicates that NO2 moiety can be replaced by other groups of comparable size and electronic properties without the loss of fungicidal activity and significantly expands the scope of potent new fungicides based on a pyrazolin-3-one fragment.

Agrochemicals doi: 10.3390/agrochemicals2010003

Authors: Dilma F. de Paula Guilherme A. de P. Ferreira Tiago Guimarães Maura G. da S. Brochado Leandro Hahn Kassio F. Mendes

Knowledge about the residual effect of herbicides is important in order to increase agronomic efficacy and reduce environmental problems. Therefore, the objective of this study was to evaluate the residual effect of oxyfluorfen and linuron in three soils. Pots of 0.35 dm3 were filled with three Brazilian soils: Ultisol, Oxisol, and Inceptisol. Then, the herbicides were applied at different times at 0, 15, 30, 45, 60, 90, 120, 150, 180, and 200 days and the bioindicator species of linuron and oxyfluorfen were sown. Then, the injury was evaluated at 7, 14, and 21 days after emergence (DAE) to find the half-life of the herbicide residue level (RL50) and the dose of herbicide that provides a 50% reduction in dry matter (GR50). In the soil with oxyfluorfen application, the RL50 at 21 DAE was 59, 57, and 51 days and GR50 was 49, 47, and 31 days for Ultisol, Oxisol, and Inceptisol, respectively. Soils with linuron application had RL50 of 75, 92, and 149 days and GR50 of 52, 48, and 120 days for Ultisol, Oxisol, and Inceptisol, respectively. The higher organic matter and clay content of Ultisol compared to Oxisol and Inceptisol resulted in a lower residual effect of linuron. There was little difference between soil type and the residual effect of oxyfluorfen, which may be related to the physicochemical characteristics of the molecule.