Search Results (4,068)

Fine-grained oriented ship detection remains challenging because visually similar vessel categories may exhibit substantial variations in scale, aspect ratio, and orientation. To address these challenges, this study proposes YOLO26-OBB-HMS (Hierarchical Multi-Label Supervision), a hierarchy-aware extension of YOLO26-OBB that integrates a pre-pyramid Axis-wise Context Block, local-window Feature Guidance, assignment-aligned parent-level supervision, and training-time Poincaré path learning while preserving the detector’s native oriented-box formulation and leaf-level inference scoring. Under the common class-wise AP50 evaluation protocol, the proposed n- and s-scale variants achieved 77.5% and 82.7% on the filtered HRSC2016 test partition and 75.4% and 80.6% on the prepared ShipRSImageNet final-evaluation partition, respectively. Full article

Nanotechnology offers approaches to improve crop productivity through nutrient delivery. This study investigated the concentration-dependent effects of foliar-applied zinc oxide nanoparticles (ZnO-NPs) on growth, photosynthesis, antioxidant defense, redox homeostasis, and yield of mustard (Brassica juncea L.) ZnO-NPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy, confirming a crystalline hexagonal wurtzite structure with a crystallite size of 29.3 nm and an aggregated morphology. Plants were treated with 25, 50, 75, or 100 mg/L ZnO-NPs and evaluated at 30 and 45 days after sowing, with yield assessed at harvest. Responses were concentration-dependent, with 50 mg/L producing the greatest benefits. This treatment enhanced growth, biomass, SPAD index, leaf area, gas exchange, PSII efficiency, carbohydrate and protein accumulation, antioxidant enzyme activities, leaf elemental composition, and yield traits. It also reduced reactive oxygen species, malondialdehyde, and electrolyte leakage while increasing proline and glutathione, indicating improved redox balance and membrane stability. Among the concentrations tested, 50 mg/L ZnO-NPs produced the most consistent beneficial response under the present experimental conditions, whereas the magnitude of these effects declined at 75 and 100 mg/L. These findings highlight the significance of concentration optimization while considering the use of ZnO-NPs as foliar treatment in B. juncea for Zn fertilization. Nevertheless, further comparative studies using conventional Zn fertilizers are necessary to determine whether the observed responses are specifically associated with the nanoscale properties of ZnO-NPs or are primarily attributable to Zn nutrition. Full article

Variation in illumination and canopy geometry can affect the comparability of RGB measurements acquired at different times of day. This study proposes a wheat canopy reflectance correction method guided by leaf-colour and shadow-structure features. UAV RGB images were acquired under different nitrogen rates, sampling dates and acquisition times. SP, HSV, Lab and BDI features were extracted to build four input schemes, which were fed into multiple neural networks for correction. The Fullgrade_noflat input, which retains the BDI grade order, combined with 1D-CNN gave the most accurate predictions of the plot-level daily mean RGB reference among the tested configurations (R² = 0.8773, RMSE = 0.0213 and MAE = 0.0161). The within-day CV decreased for all three RGB channels. The model also yielded lower errors than three RGB shadow-compensation implementations evaluated on the same dataset. These results indicate improved within-day consistency under the conditions studied; performance in other environments and effects on agronomic trait analysis require further evaluation. Full article

How retrieval performance varies with simulation settings, neural architecture, and measured-data adaptation remains unclear for hyperspectral crop trait retrieval. Here, we evaluated winter wheat leaf area index (LAI) and canopy chlorophyll content (CCC) retrieval using two simulated datasets and four dual-branch neural architectures. Models were pretrained on two PROSAIL-D datasets with default and previously optimized leaf-angle settings and then adapted separately to ground and unmanned aerial vehicle (UAV) observations. Evaluation used five repetitions with physical-plot grouping, with approximately 30% of plot groups allocated to measured-data adaptation. Simulation-trained random forest (RF) and partial least squares regression served as baselines without measured-data adaptation. Adaptation reduced mean test root mean square error (RMSE) in all 32 neural model–dataset–target–platform combinations relative to direct simulation-based prediction. Dataset II, which used the previously optimized leaf-angle setting, reduced mean RMSE in 13 of 16 neural configurations before adaptation and 11 of 16 afterwards. No neural architecture was uniformly best. RF achieved the highest mean R² in seven of eight simulation-only tasks and outperformed the adapted Dataset II CNN–Transformer on both UAV targets. Despite adaptation gains, all adapted neural configurations retained negative mean R² for UAV CCC. These findings support measured-data adaptation within the tested protocol, while showing that the effects of simulation design and architecture are task dependent and that relative improvements do not necessarily imply adequate absolute predictive accuracy. Full article

The species Bidens subalternans DC., belonging to the Asteraceae family, is a native plant of Brazil. The objective of this study was to perform preliminary phytochemical characterization and evaluate the antioxidant activity and acute toxicity of the ethanol extract (EE) and leaf fractions of B. subalternans. Phytochemical screening revealed the presence of steroids, saponins, alkaloids, coumarins, flavonoids and tannins. Analysis of the EE and the dichloromethane fraction (DCMF) by gas chromatography–mass spectrometry (GC-MS) suggested the presence of phytol, ethyl esters, fatty acids, terpenoid compounds, stigmasterol, untriacontane, ketones, and loliolide. The presence of chlorogenic acid, cinnamic acid derivatives, coumaric acid derivatives, caffeic acid derivatives, and flavonoids was putatively assigned using high-performance liquid chromatography coupled with a diode-array detector (HPLC-DAD). The ethyl acetate fraction (EAF) and DCMF showed higher levels of total phenolic compounds and flavonoids compared to the EE and hydroethanol fraction (HEF) (EAF > DCMF > EE > HEF). In antioxidant activity assays, the EAF exhibited the greatest potential, followed by the DCMF, EE, and HEF. The results showed no mortality of Artemia salina larvae, indicating an absence of acute toxicity under the tested conditions. This study contributes to the preliminary chemical characterization of B. subalternans, toxicity and antioxidant activity in vitro, highlighting it as a potential source of natural antioxidants. Full article

Mechanical grain harvesting (MGH) reduces post-harvest losses and improves operational efficiency in maize, but its adoption is limited mainly by grain breakage arising from excessive grain moisture content (GMC) at harvest. To assess the potential and underlying mechanisms of nitrogen (N) fertilizer management in modulating maize grain moisture, a three-year field study (2023–2025) was conducted in the irrigated oasis zone of Northwest China. In 2023–2024, a single-factor experiment on hybrid DK159 tested four N fertilizer application rates (0, 300, 375 and 450 kg/ha); in 2025, the design was expanded to two hybrids (DK159 and XY1225), two planting densities (7.5 × 10⁴ and 11.25 × 10⁴ plants/ha) and an 18-level N gradient (0~765 kg/ha). Elevated N advanced silking by 2~3 d but delayed physiological maturity (PM) by 6~7 d, a ‘promote-early but delay-late’ phenological effect in 2023–2024. The effect of N on GMC was small and hybrid- and density-dependent: under high density, GMC of XY1225 increased by approximately 0.34% per 100 kg N, whereas DK159 responded minimally. N did not consistently alter post-PM grain dehydration rate (GDR), and leaf area index (LAI) at PM showed no significant linear relationship with GDR. Although some N–GMC associations were statistically significant, they were small, partly confounded by N-induced phenological delay, and associative rather than mechanistic, because key canopy physiological variables (microclimate, transpiration, stomatal conductance) were not measured. Interactive hybrid × density effects derive solely from the 2025 dataset and require cautious generalization. We conclude that N management has limited, context-dependent capacity to lower GMC at harvest toward MGH-suitable levels and that PM-measured LAI is not a primary structural determinant of grain dehydration; breeding hybrids with intrinsically rapid dehydration should therefore be prioritized over N management as a tool for lowering GMC. Full article

Plantago fengdouensis is an endangered species threatened by habitat loss, population fragmentation, and cadmium (Cd) contamination. This study evaluated the effects of exogenous melatonin (MT) on Cd tolerance from seed germination to the seedling stage. In Petri-dish assays, 50–100 mg L⁻¹ Cd markedly inhibited germination; 50 mg L⁻¹ was selected as the lowest concentration producing severe inhibition while retaining sufficient germination for mitigation testing, and 100 μM MT provided the strongest alleviation. In pot experiments, MT promoted seedling growth, shoot and root biomass accumulation, and root and leaf development while reducing Cd accumulation and root-to-shoot translocation. Physiological analyses showed that 200–250 μM MT most effectively alleviated Cd-associated damage by maintaining photosynthesis, enhancing antioxidant and osmotic-adjustment responses, and modulating endogenous hormones. Transcriptome analysis identified 4871 differentially expressed genes (DEGs) between C50M200 and C50M0, with prominent enrichment in plant hormone signaling, cell-wall/plasma-membrane functions, secondary metabolism, and photosynthesis. Exploratory weighted gene co-expression network analysis (WGCNA) further identified treatment-associated modules and candidate hub genes. Overall, the data support coordinated MT-associated responses involving stronger antioxidant defense, reduced Cd accumulation/translocation, and hormone-signaling remodeling. Because transcriptomes were obtained from leaves and WGCNA included nine samples, the inferred molecular mechanisms should be regarded as candidate pathways pending targeted expression and functional validation. Full article

The distribution of leaf sizes along a shoot is a fundamental aspect of plant architecture, but a simple quantitative rule for this pattern has not been widely tested. We examined whether the ascending leaf length sequence per culm in six Indocalamus bamboo species follows a geometric series. This hypothesis is particularly plausible for Indocalamus bamboos because their leaves are concentrated near the culm apex, resulting in relatively uniform light exposure across the leaf cohort. However, the culm architecture is not entirely uniform: some leaves arise from smaller, thinner branches, which could naturally generate a geometric size sequence. To test this hypothesis, we measured the lengths of all leaves from 602 culms across the six species. After excluding culms with fewer than three or more than 90 leaves and those with estimated common ratios exceeding 1.2, we retained 577 culms for final analysis, representing 95.8% of the initial sample. For each culm, we fitted a geometric series model to the ascending leaf length sequence using nonlinear least-squares regression. The goodness of fit was evaluated using the mean absolute percentage error (MAPE) between observed and predicted cumulative leaf lengths. The results showed that the geometric series model fitted the data remarkably well, with 75.39% of the 577 culms having a MAPE below 5% and 96.53% below 10%. The estimated common ratios ranged from 1.01 to 1.19, with a mean of 1.05, indicating a modest but consistent geometric increase in leaf length. Significant differences in both the estimated common ratio and the estimated minimum leaf length were found among species, reflecting interspecific variation in growth strategies. These findings provide strong support for the geometric series as a robust descriptor of leaf length organization per culm in bamboos, offering new insights into the architectural structures that constrain the leaf size distribution per culm. Full article

Efficient irrigation is pivotal for viticulture in arid regions; however, solutions that simultaneously stabilize vine water status, sustain yield, and preserve fruit quality remain limited. We evaluated a microfiber-based wicking infiltration irrigation system—applied at the surface (W1) and shallow-buried at 10 cm (W2)—against drip (DI) and furrow (FI) irrigation in a two-year field trial with table grapes in northwest China. Additional wicking infiltration irrigation quota treatments (W1-2/3, W1-1/3) were also tested. The experiment combined continuous root-zone moisture and predawn leaf water potential (Ψpd) measurements with assessments of growth, berry traits, anthocyanins, and expression of related genes, synthesizing outcomes using an AHP–entropy multi-criteria framework. Wicking infiltration irrigation reduced wet–dry fluctuations, increased minimum soil moisture, and mitigated excursions to low Ψpd relative to DI and FI, indicating a more stable hydraulic environment for vines. W2 and W1-2/3 delivered the highest or near-highest yields (up to 16.5 kg per vine). Relative to DI, W2 increased IWUE by 57.9% in 2018 and 9.3% in 2019, whereas W1-2/3 increased IWUE by 155.1% and 66.0%, respectively. The AHP–EW evaluation identified W2 as the best overall integrated treatment, with the highest cumulative score across the two years (1.22), while W1-2/3 provided the strongest yield–IWUE balance under reduced irrigation. Anthocyanin accumulation and the expression of related biosynthetic genes showed year- and treatment-dependent responses; moderate water deficit was associated with enhanced anthocyanin-related responses at some developmental stages, but this effect was not consistent across seasons. These results indicate that wicking infiltration irrigation can improve grape production and irrigation efficiency under arid conditions, although its effects on berry secondary metabolism depend on seasonal and irrigation conditions. Full article

The objective of this study was to evaluate the regrowth capacity of Amelichloa clandestina at different regrowth intervals after non-selective grazing in different seasons of the year. The study was carried out on a 2.23 ha⁻¹ site in northeastern Mexico. Plots of 600 m² were used, with three replications, and were subjected to grazing at 333 LU ha⁻¹ at the beginning of every season, with biweekly evaluations. Dry matter yield (DMY) was determined by harvesting 1 m² per plot and extrapolating it to kg ha⁻¹. Morphological composition was evaluated from a 10% subsample of the total biomass. The height of 12 plants and light interception were measured with a ruler and a Quantum meter, respectively. The data were analysed using a randomized complete block design (RCBD) with a split-plot in time structure, evaluating Season (S), Days After Regrowth (DAR), and their interaction (S × DAR). Means were compared using the Tukey test in JMP 14 Pro. In autumn, DMY peaked at 535.0 kg ha⁻¹ at 90 DAR (p ≤ 0.05), accompanied by a maximum canopy height of 28.7 cm and a light interception of 30.3% at the same interval. Leaf biomass was highest in autumn, with a seasonal mean of 220.8 kg ha⁻¹ across all regrowth intervals. A significant correlation was found between plant height and light interception (r = 0.67, p ≤ 0.001). Autumn favoured A. clandestina productivity under a high stocking rate. Full article

Salinity stress, exacerbated by water scarcity, climate change, and irrigation practices, is a growing challenge to agricultural sustainability and crop yield. This study aimed to alleviate salinity stress in ‘Crimson Seedless’ grapevines through the application of biostimulants, including seaweed extract (SW), glutathione (GSH), and 24-Epibrassinosteroid (BR) alone, or in combination during the 2024 and 2025 seasons. Compared with the control, biostimulant applications significantly improved vegetative growth, leaf macro- and micronutrient contents, bud development parameters, wood-ripening parameters, pruning weight, yield components, and biochemical responses. Grapevines treated with SW at 8 L ha⁻¹ + GSH at 0.2 g L⁻¹ + BR at 2 mg L⁻¹ exhibited the most pronounced improvements among the tested biostimulant treatments compared with the control. Compared with the control, this treatment increased the yield per vine, leaf surface area, total chlorophyll content, bud burst, and bud fertility by 63.83%, 36.49%, 37.11%, 31.67%, and 57.14%, respectively. It also increased the leaf petiole mineral nutrient contents, with N, P, K, Ca, Mg, Zn, Mn, and Fe rising by 37.11%, 39.93%, 15.30%, 37.55%, 36.02%, 37.11%, 38.19%, and 37.11%, respectively, while reducing Na and Cl contents by 42.76% and 34.41%, respectively. SW + GSH + BR markedly enhanced the antioxidant defense by increasing superoxide dismutase (SOD), ascorbate peroxidase (APX),, catalase (CAT), peroxidase (POX), and GR activities by 85.06%, 88.06%, 55.35%, 225.84%, and 61.13%, respectively, compared with the control. Conversely, it reduced Malondialdehyde (MDA), polyphenol oxidase (PPO), and proline contents by 33.18%, 69.31%, and 19.16%, respectively. These findings support the potential of combined biostimulant application as a management strategy for improving grapevine performance under salinity stress. Full article

Urban greening programs in Chinese megacities are premised on the assumption that vegetation cools the surface and improves air quality simultaneously, yet greenness is usually quantified in two dimensions and the thermal and air-quality services are evaluated separately, so the places where they reinforce or conflict remain unmapped. We measured effective leaf area index (LAIe) in 570 quadrats across 30 vegetated plots in Guangzhou, China, and found that, under the spatial and temporal conditions tested, planar spectral data represented it poorly: Moderate Resolution Imaging Spectroradiometer (MODIS) LAI was only weakly correlated with field values (r = 0.15, n = 395), 87.9% of LAIe variance occurred within plots, and all 16 locally calibrated vegetation-index models showed no skill under plot-grouped cross-validation (CV-R² ≤ 0). We therefore represented three-dimensional greenness with a structural proxy, layered vegetation volume (LVV, m³ m⁻²), defined as the product of cell-mean 10 m canopy height and tree-cover fraction (a cover-weighted canopy-height index), and coupled it with warm-season Landsat land surface temperature (LST) and 1 km estimates of PM_2.5 (2016–2022), warm-season daily maximum 8 h average (MDA8) O₃ (2016–2022) and NO₂ (2019–2022) on 1, 2, 3 and 5 km grids, analyzed with ordinary least squares (OLS), geographically weighted regression (GWR), multiscale geographically weighted regression (MGWR) and extreme gradient boosting with Shapley additive explanations (XGBoost–SHAP). The results show the following: (1) MGWR achieved lower corrected Akaike information criterion (AICc) than OLS and GWR at every scale where it was fitted (2, 3 and 5 km), and the LVV term operated at a bandwidth of 43 neighbors (median radius ≈ 12 km) versus ≥863 neighbors (≈108 km, effectively citywide) for meteorological covariates; (2) one standard deviation of LVV (7.4 m³ m⁻²) was associated with 1.3 °C lower warm-season LST (significantly negative in 75% of cells at |t| > 1.96 and 37% under MGWR-adjusted critical values), 0.30 μg m⁻³ lower PM_2.5 (69% and 50%) and 1.3 μg m⁻³ lower NO₂; (3) the citywide O₃ effect was null, but MGWR revealed offsetting local responses (31% of cells significantly negative, 17% positive), and within-cell greening was associated with rising O₃ (+0.19 SD, p < 0.001), and annual coefficients turned non-negative after 2020 as nitrogen oxides (NO_x) declined; (4) the PM_2.5 benefit leveled off near 13.6 m³ m⁻² (bootstrap 95% CI 8.4–15.2), while the cooling response flattened gradually with a poorly constrained breakpoint, and cells classified as full synergy, partial synergy, O₃ trade-off and insensitive covered 44.6%, 36.3%, 15.0% and 4.1% of the municipality, with trade-off cells concentrated in the hottest, most built-up southern lowland belt; under stricter significance criteria the classified shares contracted, while the trade-off cells remained in this belt. These results suggest that structure-based, zone-specific greening targets may help secure co-benefits while anticipating a possible ozone penalty in NO_x-rich areas. Full article

Apple bitter rot (ABR) and Glomerella leaf spot (GLS), caused by Colletotrichum spp., have recently become an increasing concern in most Italian apple-growing areas. Surveys were conducted between 2023 and 2025 in 28 commercial apple orchards in Piedmont, Northwestern Italy, to investigate the occurrence and diversity of Colletotrichum species associated with symptomatic fruits and leaves. A total of 155 isolates were obtained and initially screened using gapdh, while 49 representative isolates were selected for species-level identification through multilocus phylogenetic analyses. Five species belonging to the C. gloeosporioides and C. acutatum species complexes were identified: C. chrysophilum, C. alienum, C. fioriniae, C. godetiae, and C. nymphaeae. Eight representative isolates were evaluated for mycelial growth at different temperatures and pathogenicity on apple fruits and leaves, revealing differences in growth and virulence. All tested isolates were pathogenic and fulfilled Koch’s postulates. Isolates were characterized for their in vitro sensitivity to fludioxonil, mefentrifluconazole, and pyraclostrobin. EC₅₀ values were generally low, although greater variability was observed, particularly within the C. gloeosporioides species complex for pyraclostrobin. This study expands current knowledge of the Colletotrichum species associated with ABR and GLS in apple production and provides relevant biological and fungicide sensitivity data as a reference for future epidemiological investigations and disease management strategies. Full article

Blumea balsamifera is traditionally used in Thai herbal remedies for fever management; however, its antiplasmodial potential has not been comprehensively investigated. In this study, we evaluated the in vitro and in vivo antiplasmodial activities, phytochemical profile, and acute oral toxicity of B. balsamifera leaf extracts. Antiplasmodial activity against Plasmodium falciparum K1 and cytotoxicity against Vero cells were determined using the parasite lactate dehydrogenase (pLDH) assay and an MTT assay, respectively. Phytochemical constituents of the ethanolic extract were characterized by liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). In vivo antiplasmodial assessment was investigated in Plasmodium berghei ANKA-infected mice using Peters’ four-day suppressive test at oral doses of 200, 400, and 600 mg/kg. Acute oral toxicity was evaluated following a single oral dose of 2000 mg/kg. The ethanolic extract exhibited promising in vitro antiplasmodial activity, with an IC₅₀ value of 2.65 µg/mL and a selectivity index (SI) of 23.03, whereas the aqueous extract was inactive (IC₅₀ > 40 µg/mL). LC-QTOF-MS analysis of the ethanolic leaf extract tentatively identified 16 compounds in the negative ionization mode and 30 compounds in the positive ionization mode. In the four-day suppressive test, the ethanolic extract demonstrated dose-dependent antiplasmodial activity, with parasitemia suppression of 42.29%, 70.74%, and 76.54% at doses of 200, 400, and 600 mg/kg, respectively. In the acute toxicity study, no mortality, abnormal clinical signs, or significant changes in body weight, food consumption, or water intake were observed. Furthermore, no evidence of hepatotoxicity or nephrotoxicity was detected. The ethanolic leaf extract of B. balsamifera demonstrated antiplasmodial activity in both in vitro and in vivo models, with favorable selectivity and no apparent acute toxicity at the tested dose. These findings support the potential of B. balsamifera as a source of antiplasmodial compounds and provide a basis for further phytochemical isolation and mechanistic studies. Full article

Climate change-driven high-temperature stress has become a major threat to global wheat production, and developing effective strategies to ensure heat-resilient, stable-yield cultivation is an urgent scientific priority. Mn₃O₄ nanozymes, a newly developed type of nanozyme, have not yet been tested for improving wheat heat tolerance. This study investigated the physiological mechanisms by which Mn₃O₄ nanozymes alleviate high-temperature stress during wheat grain filling. A polyethylene film greenhouse simulated a high-temperature environment, increasing the average canopy temperature of wheat by 2–3 °C. Under stress, plants were sprayed with distilled water (M0) or with Mn₃O₄ nanozymes at 100 (M1), 150 (M2), or 200 mg·L⁻¹ (M3), while an additional control (CK) was sprayed with distilled water under natural conditions. Compared with the CK, high-temperature stress significantly disrupted chloroplast structure, altered stomatal morphology, and reduced SPAD values, flag leaf area, and photosynthetic parameters in flag leaves, ultimately leading to a decrease in thousand-kernel weight (down 4.86%) and wheat yield (down 21.24%); in contrast, under high-temperature stress, Mn₃O₄ nanozyme treatment resulted in milder damage to chloroplast membrane structure; the thylakoid membrane system exhibited a slightly relaxed state overall, and stomatal aperture remained favorable. This treatment slowed the decline in photosynthetic capacity and significantly enhanced antioxidant enzyme activity, thereby mitigating the impact on yield. Among these, the M1 treatment yielded the best results, with thousand-kernel weight and yield increasing by an average of 2.62% and 18.26%, respectively, compared to M0; however, this mitigating effect diminished as the concentration rose. Compared with the M0 treatment, M2 and M3 treatments produced average yield increases of 9.04% and 5.34%, respectively. Therefore, Mn₃O₄ nanozymes at an appropriate concentration can mitigate the adverse effects of high-temperature stress on wheat at multiple levels, thereby effectively alleviating yield losses during the grain-filling stage. Full article