Agrochemicals

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article