Search Results (87)

Manual fruit thinning is labor-intensive and inefficient, making the development of intelligent visual detection systems a crucial approach for improving the quality and production efficiency of the pear industry. However, in natural orchard environments, young pear fruits are small in size with slender fruit stalks, and their texture and color characteristics are highly similar to those of tender branches. Furthermore, variations in illumination and occlusions caused by branches and leaves make it difficult for existing detection models to simultaneously and accurately identify fruits and fruit stalks, limiting their application in automated thinning equipment. In this study, Yuluxiang pear was selected as the research object, and image data were collected under diverse field conditions, including forward-lighting, backlighting, close-range shooting, long-range shooting and fruit overlapping. A dedicated dataset containing 3057 images was established. Based on the RT-DETR-R18 network, a lightweight and high-precision fruit–stalk synchronous detection model was proposed. Specifically, the backbone network was reconstructed by integrating GCConv with C2f modules to enhance global feature extraction for slender fruit stalks. The bottleneck structure was optimized using GCConvC3 to reduce feature degradation under occlusion conditions, and an additional 4× down-sampling P2 detection head was introduced to improve the detection capability for small targets. To fully validate the model performance and stability, three types of experiments were conducted in this study: ablation experiments, repeated experiments with different random seeds, and comparative experiments. Ablation experiments verified the cumulative performance improvements brought by the introduced modules. Repeated experiments with different random seeds were performed to explore training randomness-induced performance fluctuations, and the results demonstrated that the proposed model maintains stable overall detection accuracy with minor metric fluctuations. Comparative experiments demonstrated that the proposed model achieved a compact parameter size of only 15.97 M, with a precision of 95.0% for young pear fruit detection and an mAP50 of 83.0% for fruit stalk detection, outperforming all comparative models in overall mAP50. The training convergence curves and Grad-CAM++ visualization results further confirmed the stable optimization process and enhanced feature attention capability of the proposed model. By achieving a favorable balance between detection accuracy and model lightweightness, this approach provides effective technical support for the development of intelligent fruit thinning equipment and vision-based systems for smart pear orchards. Full article

Exopolysaccharides (EPS) represent an important tool for application in bio- and phytoremediation technologies due to their ability to enhance water and nutrient retention, support microclimate stability, and protect plants from environmental stress. In the present study, xanthan-like EPS produced by Xanthomonas translucens TRK8 was precipitated by ethanol and isopropanol, with the former yielding 9.2 g L⁻¹ compared with 6.7 g L⁻¹ obtained with the latter. The monosaccharide profile of the TRK8-derived EPS indicated a branched structure composed of rhamnose, mannose, glucose, and galactose residues, containing both α- and β-type pyranose units. The rheological properties of the studied EPS were compared with those of commercial xanthan at concentrations of 1–3 wt.%. Fitting the obtained data to the Ostwald–de Waele power-law model revealed that the flow behaviour index (n) values were below 1 (−0.338, −0.499, and −0.647, respectively), indicating shear-thinning behaviour (i.e., pseudoplasticity). The potential of the TRK8-derived EPS as a plant protection agent was validated by coating barley seeds with 2 wt.% EPS, resulting in a 28.6% increase in shoot length and a 64.7% increase in root length relative to the oil-stressed control. Full article

This study evaluated activities of crude extracts from different parts of the tree of heaven (Ailanthus altissima (Mill.) Swingle) collected in Slovenia and Hungary, using effect-directed analyses based on hyphenation of high-performance thin-layer chromatography (HPTLC) and nine in vitro assays performed in situ on chromatographic plates after the separation. HPTLC separation combined with a set of four antibacterial assays, two antifungal assays, and three enzyme inhibitor assays to evaluate the extracts of 15 plant parts: young shoots, young leaves, mature leaves, yellow leaves, petioles of leaves, petioles of male inflorescences, petioles of fruits, female inflorescences, young fruits, male inflorescences, mature male inflorescences, bark of 1–2-year branches, bark of 2-year branches, bark of tree trunk, and bark of roots. Antibacterial activities against Gram-positive bacteria (Bacillus subtilis, Rhodococcus fascians) and Gram-negative bacteria (Aliivibrio fischeri, Pseudomonas syringae pv. maculicola (Psm)), as well as inhibition of enzymes α-glucosidase, lipase, and acetylcholinesterase, were observed for all extracts. Extracts differed in their antifungal activities. Extracts of young shoots, mature leaves, petioles of leaves, and bark of roots showed antifungal activity against plant pathogens Fusarium avenaceum and Bipolaris sorokiniana. Extracts of yellow leaves, male inflorescences, bark of 1–2-year branches, and bark of tree trunks were only active against F. avenaceum, whereas extracts of young leaves were only active against B. sorokiniana. This study is the first to report that A. altissima extracts exhibit (1) antifungal activity against F. avenaceum and B. sorokiniana; (2) antibacterial activity against A. fischeri, Psm, R. fascians, and B. subtilis (except leaves, bark of branches and bark of tree trunks); and (3) inhibitory activity toward lipase, α-glucosidase (except bark of tree trunks), and acetylcholinesterase (except bark of tree trunks). Full article

The well-known shooting algorithm has produced important results in solving various linear as well as nonlinear BVPs, defined on unbounded intervals, but has become obsolete. The main difficulty lies in the numerical handling of the domain’s infiniteness. This paper presents a three-step strategy that significantly improves the traditional truncation algorithm. It consists of Chebyshev collocation, implemented as Chebfun, in conjunction with rational AAA interpolation and analytic continuation. Furthermore, and more importantly, this approach enables us to provide a thorough analysis of both possible errors in dealing with and the hidden singularities of some BVPs of real interest. A singular second-order eigenvalue problem and a fourth-order nonlinear degenerate parabolic equation, all defined on the real axis, are considered. For the latter, Chebfun provides properties-preserving solutions. Travelling wave solutions are also studied. They are highly nonlinear BVPs. The problem arises from the analysis of thin viscous film flows down an inclined plane under the competing stress due to the surface tension gradients and gravity, a long-standing concern of ours. By extending the solutions to these problems in the complex plane, we observe that the complex poles do not influence their behaviour. On the other hand, the real ones involve singularities and indicate how long solutions can be extended through continuity. Full article

Urban forests are highly valued for the multiple benefits they provide to city dwellers. The strategic provision of ecosystem services by these forests is threatened by climate change, warming conditions being responsible for heat waves and chronic droughts that inflict stress and mortality on trees. A three-year study (2011–2013) conducted at Parco Nord Milano (PNM) (Milano, Italy) assessed the impact of thinning interventions on the dynamics of fungal pathogens in declining forest plots. Symptomatic trees of the genera Alnus, Acer, Fraxinus, Platanus, Quercus and Ulmus, exhibited in thinned subplot pronounced decline/dieback, exhibiting symptoms like microphyllia, leaf yellowing, leaf shedding, sunken cankers, shoot wilting and branch dieback. Comparative analyses between the thinned and unthinned subplots revealed a significantly higher incidence of pathogens in the thinned one. Five species of Botryosphaeriaceae, namely Botryosphaeria dothidea, Diplodia corticola, Diplodia seriata, Dothiorella omnivora and Neofusicoccum parvum, were consistently isolated from tissues of declining hosts. There is evidence that thinning altered plot-level microclimate conditions and microbial equilibrium, favoring the proliferation of latent, pathogenic Botryosphaeriaceae. In fact, during the study period, the presence of N. parvum increased tenfold and that of B. dothidea fivefold in thinned subplot. Conversely, in unthinned subplot, the same pathogenic taxa maintained stable proportions. These results demonstrate that thinning altered ecological balances increasing tree susceptibility to harmful, cosmopolitan botryosphaeriaceous fungi. Our findings challenge assumptions about thinning as a universally beneficial practice, emphasizing the need for silvicultural strategies that take into account host and pathogen ecology and the microclimatic resilience of forest stands. This study emphasizes the importance of adaptive management in urban forestry to mitigate the unintended ecological consequences of climate change. Full article

The increasing demand for food is the driving force behind the search for novel, more selective, and less hazardous agrochemicals. Natural products are gaining prominence recently due to the promise of being green agrochemicals, but many natural products are poorly soluble in water, which reduces their applicability. In this work, we successfully formulated a water-insoluble Saussurea lappa root extract into a stable aqueous suspension using xanthan gum. The colloidal suspension was characterized by rheology, dynamic light scattering, and zeta potential. The results demonstrated that the suspension is a stable, sprayable, shear-thinning viscoelastic system (weak gel). A series of S. lappa solutions with xanthan gum were prepared and tested against five plant species, observing the inhibitory effect on the shoots and roots. The results were also compared with the commercial herbicide Dual. The S. lappa extract presented results comparable to or even greater than Dual for Lactuca sativa, Cucumis sativus, Brachiaria decumbens, and Bidens pilosa. However, it showed low inhibitory activity for Sorghum bicolor, highlighting its potential for selective weed control. This work illustrates xanthan gum as an effective vehicle for formulating insoluble natural products and demonstrates that S. lappa extract is a promising candidate for developing novel herbicides. Full article

The long-term conservation of Prunus persica (peach), a crop of significant agronomic and genetic value, remains challenging due to its recalcitrance to conventional cryopreservation methods. Low tolerance to dehydration and cryoprotectant toxicity often results in poor survival and regrowth, thereby limiting the reliability of germplasm storage. This study evaluated whether combining an alginate hydrogel matrix with Pluronic F-68 improves vitrification efficiency and post-thaw regeneration of peach shoot tips by enhancing dehydration dynamics and reducing cryo-injury. Shoot tips were immobilized in thin sodium alginate layers on aluminum foil strips, with the hydrogel providing mechanical stabilization and moderating water loss during exposure to PVS3 and subsequent liquid nitrogen immersion. To further mitigate cryoinjury, Pluronic F-68, a non-ionic surfactant with membrane-stabilizing properties, was incorporated into the system. Differential scanning calorimetry revealed that the hydrogel reached complete vitrification after 120 min in PVS3, whereas encapsulated shoot tips required 150 min for full suppression of crystallization. The optimized system achieved 71% post-cryopreservation survival and 40% regrowth, compared with 25% and 9% in non-encapsulated controls. PF-68 accelerated vitrification kinetics, lowered crystallization enthalpies, and improved post-thaw viability. These findings demonstrate that engineered hydrogel–surfactant matrices can stabilize the microenvironment during vitrification and offer a promising approach for the long-term cryopreservation of peach germplasm. Full article

Leaves represent an important organ in plant photosynthesis, and moderately rolled leaves would be beneficial in establishing an ideal plant architecture and thereby increasing rice yields. In this study, a stable inherited rolled leaf mutant was obtained via ethyl methanesulfonate (EMS) mutagenesis from japonica variety WYJ27, which was named rll2 (rolling leaf 2). rll2 showed a leaf-rolling phenotype at the seedling stage, which increased with growth. Compared with the wild type, the leaves at all levels of rll2 were significantly shorter and narrower, and the leaf-rolling index gradually decreased from the highest leaf to the third-highest leaf. Semi-thin sections showed that the bulliform cells of rll2 were significantly larger than those of the wild type, and the number of cells was significantly higher than that of the wild type. Genetic analysis showed that rll2 is controlled by a pair of recessive nuclear genes. Map-based cloning revealed that RLL2 encodes a conserved and plant-specific calpain-like cysteine proteinase. RLL2 was mainly expressed in young roots, shoots, spikelets, and panicles. Transcriptome sequencing showed that a total of 104 genes were differentially expressed in the wild type and rll2. Moreover, several transcription factor genes were significantly altered in the rll2 mutant. Taken together, our findings indicate that RLL2 plays an important role in leaf rolling by regulating bulliform cells, which may be useful in breeding rice with an ideal plant architecture. Full article

Long-term intensive cultivation has caused soil fertility decline and structural degradation in the Songnen Plain, thereby constraining maize root development and yield formation. As a fundamental conservation tillage practice, straw return enhances soil function by incorporating exogenous organic matter and regulating root-shoot physiological processes. However, the mechanism underlying yield improvement through root–photosynthesis–nitrogen synergy remains insufficiently understood. A field experiment was conducted to assess the effects of conventional tillage (CT), straw incorporation (SI), straw mulching (SM), and deep straw incorporation (DF) on maize physiological traits and yield. Compared with CT, DF markedly enhanced root morphology and physiology, increasing the root length, surface area, volume, and root-shoot ratio by 16.46%, 23.87%, 26.64%, and 51.34%, respectively. The root bleeding intensity increased by 23.63%, whereas amino acid and nitrate contents in the bleeding sap increased by 29.20% and 65.93%, respectively, indicating improved root nutrient transport capacity. The enhanced root system positively influenced shoot photosynthesis by increasing the chlorophyll SPAD value by 16.05%, net photosynthetic rate (P_n) by 11.28%, and the activities of RuBP, PEP, nitrate reductase (NR), and glutamine synthetase (GS) by 10.59%, 24.36%, 29.94%, and 12.47%, respectively. These synergistic improvements significantly promoted post-anthesis biomass accumulation and yield formation. DF increased nitrogen and dry matter accumulation at the R3 stage by 26.61% and 15.67%, respectively, and resulted in an average yield increase of 8.34%, which was primarily due to an 11.96% increase in 100-grain weight. Although SI and SM also improved certain physiological indices, their effects were weaker than those of DF. RF analysis identified sap nitrate content (RNO), bleeding intensity (RBI), root length (RL), and root volume (RV) as key yield determinants. PLS-SEM further revealed that straw return enhanced root morphology and bleeding traits (path coefficients: 0.96 and 0.82), which subsequently improved leaf photosynthetic traits (path coefficients: 0.52 and 0.39) and biomass accumulation (path coefficient: 0.71). Collectively, these improvements promoted post-anthesis nitrogen accumulation and dry matter partitioning into grains. These findings elucidated the physiological mechanism by which deep straw incorporation increased maize yield through root system optimization, providing a theoretical basis for conservation tillage optimization in the thin-layer Mollisol region of the Songnen Plain. Full article

Interest in the wine sector focusing on no- or low-alcohol wines is growing. De-alcoholation, typically a post-fermentation process, faces restrictions in some countries and is often quite costly. Using raw materials like low-sugar grapes suitable for this purpose seems logical, yet the literature currently lacks contributions in this area. In this review paper, we outline an ideal ripening process where the goal of producing “low-sugar grapes” can be achieved through various methodologies applied at (i) the whole-canopy level (minimal pruning, hedge mechanical pruning with or without hand finishing, cane pruning combined with high bud load and no cluster thinning, applications of exogenous hormones, late irrigation, and double cropping); (ii) the canopy microclimate level, involving changes in the leaf area-to-fruit ratios (netting, apical or basal leaf removal, late shoot trimming, use of antitranspirants); and (iii) through new technologies (high-yield plots from vigor maps and the adoption of agrivoltaics). However, the efforts in this survey extend beyond merely achieving the production of low-sugar grapes in the vineyard, which is indeed primary but not exhaustive. Therefore, we also explore solutions for obtaining low-sugar grapes while simultaneously enhancing features such as lower acidity, increased phenolics, and aroma potential, which might boost consumer appreciation. The review emphasizes that (i) grapes intended for low-alcohol wine production should not be viewed as a low-quality sector but rather as an alternative endeavour, where the concept of grape quality remains firmly intact and (ii) viticulture for low sugar concentration is a primary strategy, rather than merely a support to dealcoholization techniques. Full article

This paper presents a combined theoretical, numerical, and experimental analysis to investigate the lateral plastic crushing behavior and energy absorption of circular and non-circular thin-walled rings between two rigid plates. Theoretical solutions incorporating both linear material hardening and power-law material hardening models are solved via numerical shooting methods. The theoretically predicted force-denting displacement relations agree excellently with both FEA and experimental results. The FEA simulation clearly reveals the coexistence of an upper moving plastic region and a fixed bottom plastic region. A robust automatic extraction method of the fully plastic region at the bottom from FEA is proposed. A modified criterion considering the unloading effect based on the resultant moment of cross-section is proposed to allow accurate theoretical estimation of the fully plastic region length. The detailed study implies an abrupt and almost linear drop of the fully plastic region length after the maximum value by the proposed modified criterion, while the conventional fully plastic criterion leads to significant over-estimation of the length. Evolution patterns of the upper and lower plastic regions in FEA are clearly illustrated. Furthermore, the distribution of plastic energy dissipation is compared in the bottom and upper regions through FEA and theoretical results. Purely analytical solutions are formulated for linear hardening material case by elliptical integrals. A simple algebraic function solution is derived without necessity of solving differential equations for general power-law hardening material case by adopting a constant curvature assumption. Parametric analyses indicate the significant effect of ovality and hardening on plastic region evolution and crushing force. This paper should enhance the understanding of the crushing behavior of circular and non-circular rings applicable to the structural engineering and impact of the absorption domain. Full article

Graphene interfaces in layered dielectrics can support unique electromagnetic modes, but analyzing these modes requires robust computational techniques. This work presents a numerical method for computing TE-polarized eigenmodes in a planar stratified dielectric slab with an infinitesimally thin graphene sheet at its interface. The governing boundary-value problem is reformulated as coupled initial-value problems and solved via a customized shooting method, enabling accurate calculation of complex propagation constants and field profiles despite the discontinuity at the graphene layer. We demonstrate that the graphene significantly alters the modal spectrum, introducing complex leaky and surface waves with attenuation due to graphene’s conductivity. Numerical results illustrate how the layers’ inhomogeneity and the graphene’s surface conductivity influence mode confinement and loss. These findings confirm the robustness of the proposed computational approach and provide insights relevant to the design and analysis of graphene-based waveguiding devices. Full article

In recent years, severe decline and mortality events have been observed in holm oak (Quercus ilex L.) ecosystems in different Italian regions, including Puglia (southern Italy). Given the landscape and ecological relevance of holm oak forests in Apulia, a study was conducted to identify the causal agents related to this complex disease syndrome. The surveys, conducted in winter 2024 in three different woodlands, revealed the widespread occurrence of mature holm oak trees showing sudden death, crown thinning, shoot and branch dieback, sunken cankers, and root rot symptoms. Isolations performed from symptomatic samples collected from both stem and small roots yielded fungal and fungal-like colonies representing two distinct families: Botryosphaeriaceae and Peronosporaceae. Analysis of morphological and DNA sequence data allowed us to identify six distinct species, including Diplodia corticola and D. quercivora (Botryosphaeriaceae), Phytophthora cinnamomi, P. multivora, P. psychrophila, and P. asparagi (Peronosporaceae). For P. asparagi and P. psychrophila, isolated for the first time from declining holm oak trees in Italy, Koch’s postulates were satisfied by inoculating 1-year-old seedlings at the collar in controlled conditions. Thirty days after inoculation, all plants showed the same symptoms observed in the field. Overall, the data obtained highlights the co-occurrence of multiple Botryosphaeriaceae and Phytophthora species on declining holm oak trees and the discovery of a new haplotype of Diplodia quercivora. Full article

Examining the ramet system in bamboo forests can provide an important theoretical basis for strategic management. Moso bamboo is an economically important species in China, and implementing the correct management measures can play a key role in improving bamboo productivity. However, the dynamics of the Moso bamboo ramet system under timber vs. shoot forest management remain underexplored. In this study, we investigated the underground rhizome growth, bud bank structures, branch growth, and distribution patterns of bamboo ramet systems in the two main bamboo cultivation types. Shoot forest ramet systems exhibited stable early-stage rhizome renewal but instability in later stages, characterized by thin, elongated rhizomes. The opposite was observed in the timber forests. The underground bud bank of the ramet system in the shoot forest had a strong renewal ability with stable lateral bud input. However, shoot harvesting disturbed the bud bank balance. The lateral bud input in the timber forest was unstable, with the lateral buds being prone to death. The variation range and quantity of branch types in the ramet system in the shoot forest were greater than those in the timber forest. The number of branches in different parts of the ramet system was in the order of rhizome tip (RT) > middle of rhizome (RM) > rhizome base (RB). The range of variation was greater in the shoot forest. Different management methods led to growth differences in the examined bamboo ramet systems. Bamboo forest management resulted in a correlation between bud banks and ramet system renewal. Operations such as bamboo shoot harvesting significantly impacted branch growth and distribution. These findings not only provide a better understanding of the growth and management strategy of bamboo ramet systems worldwide but also provide a universal theoretical reference for the sustainable management of bamboo forests in other countries. Full article

A linear stability analysis is performed for a power-law liquid film flowing down an inclined rigid plane over a deformable solid layer. The deformable solid is modeled using a neo-Hookean constitutive equation, characterized by a constant shear modulus and a nonzero first normal stress difference in the base state at the fluid–solid interface. To solve the linearized eigenvalue problem, the Riccati transformation method, which offers advantages over traditional techniques by avoiding the parasitic growth seen in the shooting method and eliminating the need for large-scale matrix eigenvalue computations, was used. This method enhances both analytical clarity and computational efficiency. Results show that increasing solid deformability destabilizes the flow at low Reynolds numbers by promoting short-wave modes, while its effect becomes negligible at high Reynolds numbers where inertia dominates. The fluid’s rheology also plays a key role: at low Reynolds numbers, shear-thinning fluids ($n<1$) are more prone to instability, whereas at high Reynolds numbers, shear-thickening fluids ($n>1$) exhibit a broader unstable regime. Full article