ACS agricultural science & technology最新文献

Push-pull technology refers to a promising mixed cropping practice for sustainable agricultural intensification, which uses properties of intercrop and border crop species to defend a focal crop against pests. Currently, the most widely practiced system uses Desmodium spp. as intercrop and Brachiaria or Napier grass as border crops to protect maize (Zea mays) against both insect pests and parasitic weeds. Several previous studies have demonstrated the efficacy of the push-pull system, but research on the underlying chemical mechanisms has mostly been limited to laboratory and glasshouse experiments that may not fully reproduce the complexity of the system under natural conditions. To address this limitation, we performed a large-scale study in farmer-operated push-pull maize fields in three east African countries. We compared maize leaf extracts from plants grown on push-pull fields with maize from fields employing conventional agricultural practices to assess the influence of push-pull cultivation on the maize metabolome. We identified two benzoxazinoid glycosides, which are known to have antiherbivore properties and were present in greater relative abundance in push-pull-cultivated maize leaves across three countries. Our data thus suggest that maize cultivated under push-pull has an increased resistance to herbivore attack compared to maize grown under conventional local agricultural practices.

Rice varieties with low arsenic content (As) could address some aspects of human health risks linked to As-tainted rice consumption. This study evaluated 46 rice cultivars from Bangladesh for their total and speciated As (inorganic and organic) in grains. The rice varieties were cultivated under a continuously flooded irrigation system with As-tainted groundwater. The study revealed notable varietal effects on total and speciated As concentrations. The levels of total As in unpolished rice ranged from 219 to 562 μg kg^–1 among different rice cultivars, with BRRI dhan47 exhibiting the lowest and BR7 showing the highest concentrations. In brown rice, inorganic As was the dominant form, contributing 54–91% of total As. Nevertheless, a 10% polishing process can significantly diminish the levels of total As (14–39%), inorganic As (12–46%), and DMA (12–36%) found in brown rice. Grain As revealed a negative relationship between the rice grain yield and some beneficial micronutrients. Based on grain As levels, a couple of low As accumulating rice varieties have been identified, which could be promoted to grow in As-prone areas as a low-cost mitigation strategy. Consequently, screening low-accumulation rice cultivars could minimize the As load in humans, which occurs through rice consumption in As-endemic areas.

Paenibacillus larvae, a Gram-positive bacterium, is the pathogen responsible for American foulbrood (AFB), a prevalent disease that afflicts honeybees in numerous countries. P. larvae exclusively infect the honeybee larva, with no known environment supporting its germination or growth. In recent years, various methods, including fungicides, antibiotics, indoles, and bacteriophages, have been used to mitigate the harmful impact of P. larvae on honeybees. While these approaches offer therapeutic benefits, they also have drawbacks, such as antibiotic resistance and the adverse effects of these chemical compounds on hives, honey, and human health. This study presents a comprehensive method for identifying potential drug targets in P. larvae using a reverse vaccinology protocol. By using this approach, 11 putative drug targets in 9 different P. larvae subspecies were identified. Furthermore, this study provides a list of 7 potential inhibitors resulting from a thorough computational simulation of the interactions between these drug targets and bioactive compounds. In summary, this study suggests that the newly identified drug targets and their corresponding bioactive compounds may be invaluable in the development of therapeutic drugs for controlling P. larvae, the causative agent of AFB in honeybees.

To address the low phosphorus (P) use efficiency of soluble phosphate fertilizers, there is a need to develop P sources that better align with crop cycles in highly weathered tropical soils. This work’s hypothesis was that mixing or coating soluble fertilizers with biochar would reduce fertilizer solubility, allowing for a slow and steady release of P, thereby enhancing soil availability. The research aimed to evaluate the solubility and availability of P in soils treated with organophosphate fertilizers composed of biochar and triple superphosphate (TSP) under laboratory conditions. Thus, fertilizers were prepared by either mixing or coating TSP with coffee straw biochar, poultry litter biochar, or eucalyptus bark biochar in ratios of 20 and 40% biochar to 80 and 60% TSP, respectively. After these fertilizers were incubated in a red-yellow latosol for 30 days, it was found that biochar-based fertilizers had lower water solubility and a more gradual P release. PLB-based fertilizers demonstrated up to 50% lower water solubility than TSP, providing a slower and more consistent P release. The coating method resulted in a lower initial P release but a higher final release compared with the mixture. Increasing the biochar content decreased fertilizer water solubility. The results suggest that biochar addition can enhance the efficiency of soluble phosphate fertilizers by moderating P release.

In this work, hydroethanolic plant extracts (acorn husk, laurel, eucalyptus, and rockrose leaves) were screened for their content in condensed tannins (HPLC-DAD/MS), polyphenol content, antioxidant, antimicrobial, and antiviral activities, and lack of toxicity. The results showed the highest values of condensed tannins found for laurel and eucalyptus extracts, while the total phenolic content ranged within 204.54 ± 2.0/326 ± 7.0 (mg GAE/g extract), with the acorn husk extract presenting the highest content (p < 0.05). The extracts showed good antioxidant activity, which varied with the type of assay. ABTS (1013 ± 5.0/1859 ± 6.0) with the rockrose Porto extract presented the highest content, DPPH (854 ± 6.0/1565 ± 4.0) with the acorn husk extract presented the highest content, and ORAC (2855 ± 10/3703 ± 87) with the laurel extract presented the highest content; all results were expressed in μmol Trolox/g extract. The most antimicrobial extracts were the rockrose and acorn husk. In terms of virus inhibition, all extracts showed an inhibition over 90%, although eucalyptus and the acorn husk reached an inhibition close to 99%. No mutagenicity by AMES assays and no cytotoxicity were detected for the extracts. This work highlights the potential of these plant extracts representing the source of bioactive components with antioxidant capacity to be applied in foods, food packaging, development of new natural cleaning agents, and/or other applications.

Broad-spectrum antimicrobial agents are often useful for the management of phytopathogenic fungi, bacteria, and cyanobacteria species. Twenty novel 4,6-dihydroxypyrimidine hydrazones (aka IV-C) were designed based on lead scaffold 5, synthesized, chemically characterized, and evaluated for inhibitory activity against 15 fungi, 5 bacteria, and 2 cyanobacteria. The in vitro tests indicated that these IV-C exhibited a much broader spectrum than 5, especially for the IV-C9. At 50 μg/mL, IV-C9 exhibited >80% control on 11 fungi, >85% control for 5 bacteria, and 2 cyanobacteria. In the in vivo test at 200 μg/mL, the protective activity of compound IV-C9 against Monilinia fructigena and Xanthomonas oryzae pv oryzae was 94 and 58%, respectively, which was much better than that of chlorothalonil (79%) and thiodiazole copper (31%). IV-C9 also inhibited cyanobacteria Microcystis aeruginosa FACHB905 and Synechocystis sp. PCC6803 with corresponding EC₅₀ values of 0.30 and 0.82 μg/mL, being 5.8- and 3.6-fold more potent than the algicide prometryne (EC₅₀ = 1.74 and 2.97 μg/mL, respectively) and matched the efficacy of the copper sulfate (EC₅₀ = 0.29 and 0.37 μg/mL, respectively). Compared to IV-C9, IV-D1 with the hydroxyl group free shows almost 40-fold, 10-fold, and 160-fold less activity against fungi, bacteria, and cyanobacteria, respectively, confirming the importance of hydroxyl groups. Mechanistic studies showed that IV-C9 induced oxidative damage in pathogenic bacteria, affecting the morphology of bacteria and causing massive leakage of intracellular electrolytes and proteins. The results suggest that 4,6-dihydroxypyrimidine hydrazone IV-C9 has the potential to be a broad-spectrum microbial inhibitor.

This study examines the effects of replacing Camellia sinensis tea with passion fruit juice (PF_KLB) and apple juice (A_KLB) on the resulting beverages’ physicochemical profile, bioactive composition, and sensory characteristics. PF_KLB exhibited higher total acidity and alcohol content and lower total soluble solids, total sugars, reducing sugars, and nonreducing sugar contents than conventional kombucha and A_KLB. Kombucha and A_KLB contained higher levels of total phenolics and flavonoids, and antioxidant activity than PF_KLB. The sensory evaluation indicated that PF_KLB was well-regarded for its aroma but received criticism for its taste, which was perceived as sour and bitter in contrast to the sweeter taste of kombucha and A_KLB. Acidity significantly affected alcohol production and influenced product acceptance in conjunction with sugar content. A_KLB is a promising probiotic alternative to kombucha due to its favorable sensory acceptance and the presence of bioactive substances.

Preplant soil disinfestation often relies on harmful soil fumigants; however, the efficacy of sustainable alternatives using biomass amendment fermentation is limited to tillage depths (0-15 cm). This soil column study evaluated whether increasing the irrigation frequency could promote anaerobic pest-suppressive conditions in deeper soils by leaching biocidal fermentation products (organic acids) from surface-applied amendments. Columns received either singular (standard) or weekly irrigation. Almond hulls, an agricultural byproduct, were either incorporated 0-15 cm into soil or applied as a surface mulch. Oxygen and organic acids were measured at 4-50 cm over 21 days, and the experiment was conducted in triplicate. Anaerobic conditions (3% O₂) were achieved after 5 days, corresponding to acetic acid accumulation below amended layers: maximum concentrations ranged from 42 to 93 mM at 19-50 cm depths. Additional irrigation further increased concentrations in the deepest layer (50 cm) by almost 50%, demonstrating that water management can enable strategies for depth-dependent soil pest control. This may be particularly valuable for soil disinfestation ahead of the establishment of deep-rooted crops.

Preplant soil disinfestation often relies on harmful soil fumigants; however, the efficacy of sustainable alternatives using biomass amendment fermentation is limited to tillage depths (0–15 cm). This soil column study evaluated whether increasing the irrigation frequency could promote anaerobic pest-suppressive conditions in deeper soils by leaching biocidal fermentation products (organic acids) from surface-applied amendments. Columns received either singular (standard) or weekly irrigation. Almond hulls, an agricultural byproduct, were either incorporated 0–15 cm into soil or applied as a surface mulch. Oxygen and organic acids were measured at 4–50 cm over 21 days, and the experiment was conducted in triplicate. Anaerobic conditions (3% O₂) were achieved after 5 days, corresponding to acetic acid accumulation below amended layers: maximum concentrations ranged from 42 to 93 mM at 19–50 cm depths. Additional irrigation further increased concentrations in the deepest layer (50 cm) by almost 50%, demonstrating that water management can enable strategies for depth-dependent soil pest control. This may be particularly valuable for soil disinfestation ahead of the establishment of deep-rooted crops.

Electrospun multilayer nanofiber matrices developed using β-cyclodextrin, poly(vinyl alcohol), and poly(lactic-co-glycolic) acid effectively encapsulated the hexanal biomolecule and facilitated its controlled release. The multilayer nanofiber matrices loaded with hexanal (overlay method) are characterized through scanning electron microscopy (171 nm), transmission electron microscopy (73 nm), Fourier transform infrared spectroscopy (peak at 1716 cm^–1 corresponds to hexanal), X-ray diffraction (12.13 and 18.69°), and thermogravimetric analysis (340 °C). Fruits treated with hexanal-loaded multilayer nanofiber matrices by the overlay method recorded a lower loss in physiological weight, pH, total soluble solids, and total sugar content (17.61%, 5.15, 20.05° Brix, 17.32%, whereas in control 26.99%, 5.75, 23.08° Brix, and 21.34%, respectively, on 21st day of observation), and furthermore, the firmness, titratable acidity, and vitamin C (11.86 N/m, 0.54, and 8.53%) were higher than those of control (6.12 N/m, 0.38, and 5.09%, respectively). The shelf life of mango fruits (var. Alphonso) treated with multilayer nanofiber matrices was extended up to 23 days compared to that of the control fruits (12 days). Thus, the overall results suggested that multilayer nanofiber matrices effectively encapsulate hexanal and regulate its release slowly, which could be effectively used to enhance the physical and biochemical components and shelf life of fruits.