Anthracnose, caused by Colletotrichum gloeosporioides species complex and identified through internal transcribed spacer (ITS) region sequence homology, poses a major challenge to postharvest "Cat Hoa Loc" mangoes by reducing fruit quality, shelf life, and export potential. This study evaluated the efficacy of a 2.0% sodium alginate (SA) and 0.25% carboxymethyl cellulose (CMC) coating, enriched with Lactiplantibacillus plantarum (106 CFU mL-1), in controlling anthracnose and preserving fruit quality. In vitro, Lactiplantibacillus plantarum isolate LDC11 inhibited the C. gloeosporioides species complex mycelial and spore growth by 42.5% and 53.8%, respectively. The combined treatment of the SA-CMC coating with Lactiplantibacillus plantarum isolate LDC11 reduced disease incidence by 3-fold and disease severity by 2.89-fold, extending the storage period by 3 days at 25 degrees C, compared to the control. This treatment significantly preserved fruit quality, maintaining high levels of firmness, vitamin C, phenolic compounds, and chlorophyll, while also slowing respiration rates, delaying the decline in titratable acidity (TA), and impeding increases in total soluble solids (TSS). Weight loss was unaffected. Overall, the SA-CMC coating enriched with Lactiplantibacillus plantarum isolate LDC11 provides a promising, eco-friendly postharvest approach that could be applied in industrial mango preservation and export processing.
This study develops a coupled dynamic model and MATLAB/Simulink simulation framework for a shallot planter union consisting of a tractor, a working machine, a planting head, and an elastic coupling joint operating on soft soil. An eight-degree-of-freedom formulation is established using the Euler–Lagrange method and converted into a state-space representation with 16 state variables and 10 terrain-induced excitation inputs. Soil reaction is described via the Bekker pressure–sinkage relationship and linearized around the operating range for efficient simulation. The eigenvalue analysis confirms asymptotic stability of the coupled system (maxR(λ)=−2.8782), and time responses under initial perturbations remain bounded. Simulations indicate that pulse-type excitation governs peak responses, particularly in coupling yaw motion and planting head displacement, while harmonic and random excitations mainly contribute to sustained vibration levels. Frequency response analysis shows dominant low-frequency amplification of the main-body vertical motions in the range of approximately 0.5–2 Hz. The proposed framework supports preliminary vibration assessment and parameter tuning of shallot planting machinery under weak-soil field conditions.
This paper examines the design and performance of a quasi-zero-stiffness (QZS) vibration isolator aimed at enhancing low-frequency vibration isolation. The proposed system integrates a vertical spring with a pair of symmetric oblique springs to achieve high static stiffness while maintaining low dynamic stiffness near the equilibrium position. A nonlinear dynamic model is created based on the system's geometric configuration. The governing equation is then approximated to a Duffing-type form to facilitate the analysis of frequency response and transmissibility characteristics. The impact of key parameters on the system's behavior is analyzed through both frequency-domain and time-domain analyses. The results indicate that the isolation performance is significantly influenced by the adjustable parameter $x_{a}$, which regulates the system's equivalent stiffness. When this parameter is appropriately selected, the resonance peak is diminished, and the isolation region shifts toward lower frequencies. Among the evaluated configurations, the case with ${x}_{a}={0. 5}, {\gamma}=1$ demonstrate the best performance, exhibiting lower transmissibility and more stable responses under both single-frequency and multi-frequency excitations. These findings suggest that careful selection of parameters can greatly enhance the effectiveness of QZS isolators, making them suitable for applications that require low-frequency vibration reduction.
This study investigates the crashworthiness of a partially-nested bi-tubular structure filled with a coconut core, analyzing the influence of the core's cell dimensions under both axial and oblique impact conditions. Under axial loading, the coconut core reinforcement was found to enhance the structure's crushing resistance and overall energy absorption. However, performance degraded significantly under oblique impact, where premature fracture of the coconut core promoted an asymmetric flexural failure mode and reduced the energy absorption capacity. Despite this, it was observed that an optimized combination of cell geometry and core reinforcement can mitigate this performance loss. Counter-intuitively, the crushing force efficiency (CFE) was substantially higher under oblique impact compared to the axial loading cases. This is attributed to suppression of the high initial peak force characteristic of axial crushing, which produces a higher mean-to-peak force ratio during the more gradual off-axis deformation process. The findings confirm that coconut core reinforcement is a viable bio-based strategy for improving the crashworthiness of thin-walled structures, although performance is highly dependent on geometric parameters and loading direction.
Abstract. Truc NT, Thi QVC, Nhung DTC. 2026. Antifungal potential of Enydra fluctuans extract for postharvest control of Colletotrichum siamense in dragon fruit. Asian J Agric 10 (1): g100127. https://doi.org/10.13057/asianjagric/g100127. Pitaya, commonly known as red-fleshed dragon fruit, is rich in bioactive and nutritional compounds; however, its postharvest shelf life is limited due to high susceptibility to fungal diseases, particularly anthracnose caused by Colletotrichum spp. These infections significantly reduce fruit quality, shorten storage duration, and decrease economic value. This study investigated the antifungal efficacy of Whole Enydra fluctuans Phenolic Extract (WEPE) against postharvest pathogens of dragon fruit under in vitro and in vivo conditions. Fifteen fungal isolates were recovered from infected fruits, among which strain TL12 was identified as Colletotrichum siamense based on morphological characteristics and ITS rDNA sequencing. Pathogenicity tests confirmed Koch’s postulates, producing disease symptoms comparable to those observed in naturally infected fruits. To the best of our knowledge, this is the first report of C. siamense associated with postharvest anthracnose of dragon fruit in the studied region. WEPE obtained using ultrasound-assisted extraction with 45% ethanol exhibited the highest total phenolic content (18.26±1.49 mg GAE/g). In vitro assays demonstrated strong antifungal activity, with minimum inhibitory concentrations of 700 μg/mL for complete mycelial growth inhibition and 5000 μg/mL for spore germination inhibition. In vivo application of WEPE significantly suppressed anthracnose development on dragon fruit in a concentration-dependent manner. After 7 days of incubation, disease severity was reduced by approximately 30.4% and 55% at 700 and 5000 μg/mL, respectively, compared to the control. The results indicate that WEPE possesses strong antifungal potential against C. siamense and may be considered a promising natural agent for postharvest disease management in dragon fruit. However, these findings are based on short-term storage experiments under controlled laboratory conditions. Further research involving formulation optimization, extended storage evaluation, and field-scale validation is necessary before practical application in commercial postharvest systems.
