Search Results (809)

Efficient vibration based walnut harvesting relies on the accurate determination of clamping-points on tree trunks. Properly selected clamping points can significantly enhance vibration transmission efficiency while minimizing mechanical damage to trees. However, most existing studies focus on developing generalized vibration models applicable to multiple trees, often overlooking the structural uniqueness of individual trees in clamping-point determination. This study proposes a monocular vision-based method for clamping-point determination in walnut vibration harvesting. Robustness and applicability in complex orchard environments are enhanced by introducing three keypoint annotation strategies with varying levels of structural constraints, namely 5-key-part annotation (5-KAS), 2-key-part annotation (2-KAS), and single-key-part annotation (1-KAS). Pose estimation models based on the YOLO architecture, including YOLOv8-pose, YOLO11-pose, and YOLOv12-pose, were evaluated to examine the effect of structure assisted annotation, and the results show that introducing structural constraints improves detection accuracy, training stability, and robustness. The YOLOv12-pose model combined with the 5-KAS achieves the best performance, with a precision of 95.8% and mean average precision (mAP) of 95.5%. Field harvesting experiments demonstrate that clamping-point prediction incorporating structural information achieves higher and more stable net harvesting rates. Overall, the proposed method offers a reliable and deployable solution for clamping-point determination using monocular RGB images, facilitating intelligent vibration harvesting in walnut orchards. Full article

This study investigates the vibration response and energy transfer characteristics of walnut trees in mechanical vibration harvesting, aiming to improve fruit detachment efficiency and reduce structural damage. Three walnut tree architectures were classified based on branching height, trunk stiffness, canopy size, and geometric regularity. A dynamic model of the trunk was established, modeled as an equivalent conical beam with Rayleigh damping, and the clamping point was simplified to a single-degree-of-freedom system. To quantify energy transfer, three indicators were introduced: energy transfer coefficient, energy attenuation rate, and trunk overload index (OLI). Sweep-frequency experiments (9–17 Hz) were conducted at a clamping height of 80 cm. Triaxial acceleration responses were measured, and branch kinetic energy was calculated. The model-predicted natural frequencies matched the experimental acceleration peaks well, identifying a frequency-sensitive band between 15 and 17 Hz. Significant differences in energy distribution were observed among the three tree architectures. Tree 1 exhibits intense energy concentration near the trunk, with rapid energy decay along branches and the highest canopy vibration index (OLI: 6.13), indicating the highest trunk overload risk. Tree 2 demonstrates whole-tree coordinated vibration and the lowest OLI value (2.10). Tree 3 possesses two sensitive frequency bands with relatively uniform energy distribution and an OLI of 2.89. Trunk stiffness, branching height, canopy structure, and geometric irregularities collectively determine energy distribution within resonance bands and overload risk. The proposed energy metrics and OLI provide quantitative guidance for selecting excitation frequencies and controlling operational duration during walnut vibration harvesting. Full article

Woody tissue diseases of avocado (Persea americana Mill. var. Hass) pose a major phytosanitary threat due to their chronic progression, late symptom expression, and severe impact on tree stability and productivity. Although white rot has traditionally been attributed to saprobic basidiomycetes, increasing evidence suggests corticioid fungi may act as facultative pathogens in agricultural systems. This study examined corticioid basidiomycetes associated with white rot in stems and branches of avocado in Michoacán, Mexico. Field surveys revealed consistent symptoms of structural weakening, branch dieback, and wood decay. Fungal isolates obtained from symptomatic tissues and sporomes were characterized morphologically and identified through ITS-based phylogenetic analyses. Representative isolates of Grammothele spp. and Dentocorticium portoricense were evaluated in pathogenicity assays under controlled conditions. All isolates reproduced field symptoms, confirming pathogenicity, though aggressiveness varied. D. portoricense exhibited the highest incidence, severity, and AUDPC values, indicating greater virulence, while Grammothele isolates showed slower, moderate progression. Phylogenetic analyses provided robust support for D. portoricense, whereas Grammothele was resolved at genus level. Integration of field, pathogenicity, and molecular data demonstrates corticioid fungi are not merely secondary saprotrophs but relevant pathogens in avocado white rot. These findings highlight the need to include corticioid fungi in diagnostic, monitoring, and management strategies for trunk and branch diseases. Full article

Urban forests serve as representations of nature within city landscapes. Green Forest, spanning 5,198,412 square meters, has been incorporated into the Municipality of Timișoara’s public domain and designated as a forest park. This fact increased green space per capita and enriched biodiversity within Timișoara’s landscape architecture. This study explores the diversity of Green Forest trees and highlights their contribution to the urban landscape. Statistical methods, including comparative and linear relationships analyses, were employed to assess significant variations in the dendrometric parameters of the analyzed tree species: mean tree height, mean trunk diameter at breast height (DBH), tree age, and stand density. Principal Component Analysis (PCA) and cluster analysis were applied to uncover underlying patterns in the data. Using ArchiCAD and Lumion, high-quality 3D visual representations were developed for an ecological education area, an active recreation region, and a passive recreation area within Green Forest. Due to their morphological characteristics and phenotypic traits, the predominant tree species include Quercus robur, Quercus cerris, Quercus rubra, Fraxinus excelsior, Acer platanoides, Acer pseudoplatanus, Ulmus campestris, and Robinia pseudoacacia, which contribute to Timișoara’s urban aesthetic. Moreover, the results of the dendrometric analysis provide a foundation for further research in urban ecology. A key practical application of this study is landscape design renderings, which provide detailed and realistic visualizations to effectively communicate the design and functionality of Green Forest’s spaces. If implemented, these developments will encourage public engagement with nature, promoting mental and physical well-being within the community. Full article

Although a balanced supply of macronutrients is essential for apple tree growth and orchard productivity, the relationship between macronutrient uptake and partitioning in the entire apple tree remains ambiguous. To address this gap, a 2-year field experiment was conducted from 2019 to 2021 in a newly established dwarf ‘Fuji’ apple orchard in Shaanxi, one of the main apple production areas in China. The results showed that the annual uptake was 11.2−15.0 kg ha^–1 for calcium, 1.5−1.9 kg ha^–1 for magnesium, and 1.0 kg ha^–1 for sulfur. During the 2019–2020 season, trees absorbed most of the calcium, magnesium, and sulfur from the end of spring shoot growth to nutrient withdrawal, accounting for 70.8%, 76.7%, and 80.0% of the annual calcium, magnesium, and sulfur uptake, respectively. During the 2020–2021 season, 57.7%, 61.6%, and 45.5% of the annual calcium, magnesium, and sulfur uptake occurred from the slow growth of the spring shoot to the end of spring shoot growth, respectively. The ratio of nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur absorbed by the tree was 1:0.17:0.82:1.1:0.14:0.092 during the first season, and during the second season, it was 1:0.18:0.60:1.7:0.21:0.11. Regarding the accumulation and partitioning of macronutrients in different organs, calcium accumulation and partitioning were higher than those of the other nutrients in trunks. In coarse roots, branches, and shoots, calcium accumulation was also higher compared to other nutrients. In fine roots, nitrogen accumulation was slightly higher than calcium. In leaves, nitrogen accumulation was higher than the other nutrients, whereas in fruits, potassium accumulation and partitioning were higher than those of the other nutrients. These findings reveal distinct macronutrient requirement patterns across the whole apple tree and specific organs, providing new insights into maintaining nutrient homeostasis in apple trees and optimizing nutrient resource allocation for efficient orchard production. Full article

Trees play a critical role in urban ecological protection and wind disaster mitigation, yet conventional Gaussian-based wind engineering models often underestimate extreme tree motions under turbulent flows. This study aims to clarify the statistical characteristics of tree wind-induced responses and develop a quantitative framework to distinguish Gaussian and non-Gaussian behaviors. Scaled aeroelastic tree models were tested in a boundary-layer wind tunnel under controlled turbulence intensity (0.05–0.19), mean wind speeds of 3.9–9.3 m/s, and leaf area index (LAI) of 0–2.46. Acceleration and displacement time histories of branches, crown center, and trunk were recorded. A Gaussian discrimination criterion was established using cumulative probability thresholds of skewness and kurtosis, supplemented by time-history and probability density verification. Results reveal that branch accelerations exhibit strong non-Gaussianity with heavy-tailed and asymmetric distributions, crown displacements show moderate non-Gaussianity, while trunk responses remain near-Gaussian due to higher stiffness. Under weak turbulence, Gamma and Lognormal distributions fit best; under strong turbulence, the Generalized Extreme Value (GEV) distribution prevails. A high-quantile GEV-based framework markedly reduces extreme response prediction bias compared with Gaussian assumptions. These findings provide a probabilistic basis for more accurate assessment of tree wind stability and the design of wind-resistant urban vegetation and shelterbelts. Full article

Megaplatypus mutatus, a major poplar pest in South America, tunnels into the xylem, weakening trunks and reducing wood quality. Volatile organic compounds (VOCs) are key mediators of plant–insect interactions and may reflect genotype-specific defence strategies. This study analysed VOC profiles of young and adult Populus deltoides cv. Harvard and P. × canadensis cv. Conti 12 under natural M. mutatus infestation. Gas chromatography–mass spectrometry putatively annotated 31 VOCs, including green leaf volatiles (GLVs), pentyl leaf volatiles (PLVs), terpenes, alcohols, aromatics and phenolics, 12 of which, to our knowledge, have not been previously reported in Populus VOC profiles. Harvard trees showed ~14.5-fold higher total VOC abundance than Conti trees. In Conti, constitutive VOC emissions remained stable regardless of infestation status or age. In contrast, under infestation, Harvard trees emitted10-fold higher constitutive VOCs than non-infested Harvard trees and ~52-fold higher than Conti, a pattern consistent with increased defensive activity. GLVs and PLVs relatively dominated both genotypes, although Harvard showed higher emissions. Terpenes were not detected in young Conti trees under our analytical conditions but were abundant and diverse in infested Harvard trees, which may indicate a stronger terpene-associated response in this clone. Several compounds were detected only under specific genotype–condition combinations in our dataset and therefore represent candidate volatiles for future behavioural and functional studies. These results are consistent with differences in VOC emission patterns between genotypes and age classes, improve our understanding of putative chemical cues in the interaction between Populus and M. mutatus, and provide a basis for future work towards sustainable pest management strategies. Full article

In a three-year study, we investigated the efficacy of mating disruption (MD) on the spongy moth, Lymantria dispar L. in a forest complex in Slovenia. We included two treatments in the experiment: a negative control and a MD-treated area, where we used an MD product formulated as a biodegradable gel (water based, biodegradable). We applied the gel to the trunks of the forest trees (33.3 g active ingredient/ha) once per season, specifically on 4th August 2022, 28th June 2023, and 24th June 2024. To evaluate the method’s performance, pheromone traps were utilized in both treatments. The data indicate consistent effectiveness throughout the three-year period, characterized by the minimal male captures observed in the MD treatment areas after the gel was applied. The first moths were captured in the traps at DD (Degree-Day) values ranging from 661.7 to 773.3 and continued to be captured up to DD values between 1576.1 and 1642.8. Following the application of the MD, the population in the MD treatment was reduced by 100% in the first year. In the second year, the reduction was 96.33%, while in the third year of the experiment, the number of captured moths in the MD treatment was 99.20% lower compared to the control. Considering the overall data, the method disrupted Lymantria dispar male orientation effectively. Moreover, we also feel that these results show the most promise for using this method in urban and suburban areas, where L. dispar larvae can cause allergies in humans and animals and where the use of insecticides is reduced. Full article

Drosicha corpulenta (Hemiptera: Monophlebidae) is a major polyphagous pest affecting street and garden trees in arid regions of northern China, causing increasing damage in newly developed cities like Cocodala, Xinjiang. This study was conducted from 2024 to 2025 to investigate this pest’s life cycle, key damage periods, and spatial distribution in seven host plants, focusing on nymph emergence, female soil entry, and overwintering egg distribution. The results show that D. corpulenta has one generation per year, which overwinters as eggs. Nymphs emerge in early March, and male pupation occurs from mid-April to early May. Females mate after the third molt in early to mid-May and enter the soil to lay eggs from late May to early June, with consistent timing over two years. The suitability of the host varied significantly: Platanus × hispanica was the most preferred, with the highest daily nymph emergence of 840.8 individuals in 2024 and 1196.0 in 2025, followed by Prunus padus and five other plant species (Populus spp., Fraxinus chinensis, Styphnolobium japonicum, Pinus spp., and Malus spectabilis). Female soil entry reached a maximum on 23 May (979.8 individuals⁻¹ day⁻¹) and gradually decreased with increasing distance from the trunk. Overwintering eggs showed no obvious azimuthal bias, but were mainly concentrated near the trunk (0–30 cm) and in shallow soil (0–10 cm; 179.8 eggs per 100 g composite soil sample per sampling point), decreasing sharply in number with distance and depth. Both Taylor’s power law and Iwao’s regression confirmed the aggregated distribution. This study identifies key phenological stages, highly susceptible hosts, and the near-trunk shallow soil layer as critical for oviposition and overwintering and provides a basis for precise monitoring and targeted control in urban green spaces. Full article

Fertilization management is crucial mainly during the walnut training phase in order to obtain good plant formation, which is essential for guaranteeing future optimal yield. The aim of the present experiment was to evaluate the effect of different organic amendments on plant nutritional status and soil fertility in young bearing walnut trees. The experiment was conducted in 2023 and 2024 on walnut trees of the cultivar Chandler grafted on Juglans regia, planted in 2021. Since 2023, plants were yearly treated as follows: 1. non-fertilized control; 2. mineral fertilization; 3. application of municipal solid waste compost; and 4. application of compost from agri-food chain scraps. Soil amendments were supplied at the same rate as mineral fertilizer (120 kg N ha⁻¹) in spring on the tree row on a 1.5 m wide strip, while mineral fertilizer was split in two applications (50% in spring and 50% in summer). Plant growth, measured with trunk diameter and pruning wood weight, was enhanced by mineral fertilization, followed by compost, in comparison to the control. Soil mineral N was too high in relation to plant needs, with a consequent increase in the risk of nitrate leaching. Organic amendments increased soil nutrient availability, microbial activity, and carbon concentration, which, in the long term, could provide a positive environmental effect related to its sequestration into the soil. Full article

This research aims to investigate wind-induced effects numerically in full-scale Eastern Red Cedar tree (ERCT) forms under various wind speeds. A total of 72 model cases were carefully analyzed for variations in crown lengths (CLs), canopy diameters (CDs), bole lengths (BLs), and trunk diameters (TDs) at wind speeds ranging from 15 m/s to 30 m/s. The realizable k–ε turbulence model is employed to resolve the flow region and obtain drag force (FD), velocity, and pressure distributions within the computational fluid domain. The resulting aerodynamic loads are then transferred to ERCT models using a one-way fluid–structure interaction (one-way FSI) approach to predict deformation, stress, and strain in the solid zone. The accuracy of these findings was validated by comparing drag coefficient (C_D) results with those from previously conducted studies. Research results reveal that wind speed and the geometric dimensions of the tree notably influence the FD, deformation, strain, and stress experienced by the tree. When wind speed rises from 15 to 30 m/s, the amount of FD, deformation, strain, and stress increases on the ERCT. The present research helps improve the understanding of tree patterns impacted by wind, which is essential for urban design and planning. It provides guidance on how to choose and arrange necessary real trees for efficient windbreaks and comfortable surroundings in life. Full article

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, is driven by a tri-component system involving the pinewood nematode, Monochamus spp. beetle vectors, and susceptible pine hosts. Chemical control remains a scenario-dependent option for emergency suppression and high-value protection, but its deployment is constrained by strong regional regulatory and practical differences. In Europe (e.g., Portugal and Spain), field chemical control is generally not practiced; post-harvest phytosanitary treatments for wood and wood packaging rely mainly on heat treatment, and among ISPMs only sulfuryl fluoride is listed for wood treatment with limited use. This review focuses on recent progress in PWD chemical control, summarizing advances in nematicide discovery and modes of action, greener formulations and delivery technologies, and evidence-based, scenario-oriented applications (standing-tree protection, vector suppression, and infested-wood/inoculum management). Recent studies highlight accelerated development of target-oriented nematicides acting on key pathways such as neural transmission and mitochondrial energy metabolism, with structure–activity relationship (SAR) efforts enabling lead optimization. Formulation innovations (water-based and low-solvent products, microemulsions and suspensions) improve stability and operational safety, while controlled-release delivery systems (e.g., micro/nanocapsules) enhance penetration and persistence. Application technologies such as trunk injection, aerial/Unmanned aerial vehicle (UAV) operations, and fumigation/treatment approaches further strengthen scenario compatibility and operational efficiency. Future research should prioritize robust target–mechanism evidence, resistance risk management and rotation strategies, greener formulations with smart delivery, and scenario-based exposure and compliance evaluation to support precise, green, and sustainable integrated control together with biological and other sustainable approaches. Full article

Injecting chemical agents into tree trunks is a key method for preventing pine wilt disease (PWD). However, the long-term use of conventional trunk injection agents such as emamectin benzoate (EB) and avermectin (AVM) may lead to nematode resistance. Therefore, it is crucial to evaluate the potential of new-generation nematicides, including fluopyram (FLU) and its compound formulations, as alternatives to EB and AVM in PWD prevention. In this study, four trunk injection agents, i.e., 5% FLU microemulsion (ME), 2% AVM + 6% FLU ME, 5% EB ME, and 5% AVM emulsifiable concentrate (EC), were injected into Pinus massoniana trunks, and their residual dynamics over time and preventive effects on PWD were compared. Results showed that all agents were transported to various parts of the trees within 90 days post-injection, with FLU showing significantly stronger translocation compared with EB and AVM. At 660 days post-injection, the active ingredient levels of 5% FLU ME in apical branches remained significantly higher than those of the other three agents at both tested doses (30 and 60 mL). Artificial inoculation with 10,000 Bursaphelenchus xylophilus nematodes per tree at 90 days post-injection showed that trees injected with 5% FLU ME and 2% AVM + 6% FLU ME had nearly 100% disease prevention rates at both doses, outperforming 5% EB ME and 5% AVM EC. A second nematode inoculation at 480 days post-injection showed that 2% AVM + 6% FLU ME showed 50% efficacy, outperforming 5% EB ME (25% efficacy). These findings offer a foundation for developing alternative trunk injection strategies for future PWD management in China. Full article

To enhance the automation and intelligence of trenching fertilization operations, this research proposes a real-time trunk detection model (Trunk-Seek) designed for spindle-shaped orchards. The model employs a customized data augmentation strategy and integrates the YOLO deep learning framework to effectively address visual challenges such as lighting variation, occlusion, and motion blur. Multiple object tracking algorithms were evaluated, and ByteTrack was selected for its superior performance in dynamic trunk tracking. In addition, a Positioning and Triggering Algorithm (PTA) was developed to enable precise localization and triggering for target-oriented fertilization. The system was deployed on an edge device, a test bench was established, and both laboratory and field experiments were conducted to validate its performance. Experimental results demonstrated that the detection model achieved an mAP50 of 98.9% and maintained a stable 32.53 FPS on the edge device, fulfilling real-time detection requirements. Test bench analysis revealed that variations in trunk diameter and operation speed affected triggering accuracy, with an average dynamic localization error of ±1.78 cm. An empirical model (T) was developed to describe the time-delay behavior associated with positioning errors. Field verification in orchards confirmed that Trunk-Seek achieved a triggering accuracy of 91.08%, representing a 24.08% improvement over conventional training methods. Combining high accuracy with robust real-time performance, Trunk-Seek and the proposed PTA provide essential technical support for the development of a visual target-oriented fertilization system in modern orchards. Full article

To address the challenges in unstructured orchard environments, including high geometric similarity between fruit trees (with the measured average Euclidean distance difference between point cloud descriptors of adjacent trees being less than 0.5 m), significant dynamic interference (e.g., interference from pedestrians or moving equipment can occur every 5 min), and uneven terrain, this paper proposes an improved mapping algorithm named OSC-LIO (Orchard Scan Context Lidar Inertial Odometry via Smoothing and Mapping). The algorithm designs a dynamic point filtering strategy based on Euclidean clustering and spatiotemporal consistency within a 5-frame sliding window to reduce the interference of dynamic objects in point cloud registration. By integrating local semantic features such as fruit tree trunk diameter and canopy height difference, a two-tier verification mechanism combining “global and local information” is constructed to enhance the distinctiveness and robustness of loop closure detection. Motion compensation is achieved by fusing data from an Inertial Measurement Unit (IMU) and a wheel odometer to correct point cloud distortion. A three-level hierarchical indexing structure—”path partitioning, time window, KD-Tree (K-Dimension Tree)”—is built to reduce the time required for loop closure retrieval and improve the system’s real-time performance. Experimental results show that the improved OSC-LIO system reduces the Absolute Trajectory Error (ATE) by approximately 23.5% compared to the original LIO-SAM (Tightly coupled Lidar Inertial Odometry via Smoothing and Mapping) in a simulated orchard environment, while enabling stable and reliable path planning and autonomous navigation. This study provides a high-precision, lightweight technical solution for autonomous navigation in orchard scenarios. Full article