Search Results (631)

The impact of five different nets—conventional black, grey, white, and photoselective red and yellow—on the performance of “Gala Redlum” apples was evaluated over a five-year period (2020–2024) and compared to an uncovered control. The cumulative production over this period, ranked from highest to lowest, was as follows: white net (182.4 t/ha), grey net (178.5 t/ha), yellow net (175.8 t/ha), black net (175.5 t/ha), red net (169.5 t/ha), and uncovered control (138.8 t/ha). Vegetative growth results were inconsistent among the studied years. The cumulative photosynthetic rate (An) was slightly higher under the white net (57.9 µmol m⁻² s⁻¹). Fv/Fm values remained closest to optimal levels under the black and grey nets. Netting effectively protected fruits from elevated temperatures, particularly under the grey net, and reduced sunburn damage, with the grey, black, and yellow nets performing best in this regard. Overall profitability was increased by netting: the black net provided the highest cumulative income per hectare over a five-year period (EUR 72,315) alongside the second-lowest sunburn loss (0.69%), while the yellow net also showed strong economic performance (€64,742) with a moderate sunburn loss (1.26%) compared to the red net. Fruit dry matter and soluble solids content (SSC) were generally higher in the uncovered control, whereas °Hue values tended to be higher under the red and yellow nets. In summary, the black and yellow nets provided more balanced microclimatic conditions that enhanced tree performance, particularly under heat stress, leading to improved yield and profitability. However, the economic feasibility of each net type should be evaluated in relation to its installation and maintenance costs. Full article

This study evaluated the influence of different male date palm cultivars, distinguished by their chloroplast haplotypes, on pollen quality, pollination efficiency, metaxenia effects, and gene expression during fruit development. Chloroplast DNA analysis of 37 male trees revealed multiple haplotypes, from which cultivars B25, P8, C22, and B46 were selected for further investigation. Pollen viability varied significantly among cultivars, with P8 and B25 exhibiting the highest germination rates and pollen tube elongation, while C22 showed the lowest. These differences correlated with pollination success: P8 and B25 achieved fertilization rates near 99%, whereas C22 remained below 43%. Pollination outcomes also varied in fruit traits. Despite its low pollen performance, C22 induced the production of larger fruits at the Bleh (Kimri) stage, potentially due to compensatory physiological mechanisms. Phytochemical profiling revealed significant cultivar effects: fruits from B25-pollinated trees had with lower moisture and polyphenol content but the higher sugar levels and soluble solids, suggesting accelerated maturation. Ripening patterns confirmed this finding, with B25 promoting the earliest ripening and B46 causing the most delayed. Gene expression analysis supported these phenotypic differences. Fruits pollinated by P8, B25, and B46 exhibited elevated levels of cell-division-related transcripts, particularly the PdCD_1 gene (PDK_XM_008786146.4, a gene encoding a cell division control protein), which was most abundant in P8. In contrast, fruits from C22-pollinated trees had the lowest expression of growth-related genes, suggesting a shift toward cell expansion rather than division. Overall, the results show the critical role of male genotype in influencing fertilization outcomes and fruit development, offering valuable insights for targeted breeding strategies at enhancing date palm productivity and fruit quality. Full article

Fe deficiency in apple trees can lead to leaf chlorosis and impede root development, resulting in significant alterations in signaling, metabolism, and genetic functions, which severely restricts fruit yield and quality. It is well established that WRKY transcription factors (TFs) are of vital significance in mediating plant responses to abiotic stress. Real-time quantitative fluorescence (RT-qPCR) analysis displayed that Fe deficiency stress can significantly induce WRKY69 TF gene expression. However, the potential mechanisms by which the WRKY69 gene involved in Fe deficiency stress remains to be investigated. To address this limitations, the WRKY69 gene (MD09G1235100) was successfully isolated from apple rootstock Malus halliana and performed both homologous and heterologous expression analyses in apple calli and tobacco to elucidate its functional role in response to Fe deficiency stress. The findings indicated that transgenic tobacco plants exhibited enhanced growth vigor and reduced chlorosis when subjected to Fe deficiency stress compared to the wild type (WT). Additionally, the apple calli that were overexpressed WRKY69 also exhibited superior growth and quality. Furthermore, the overexpression of the WRKY69 gene enhanced the ability of tobacco to Fe deficiency stress tolerance by stimulating the synthesis of photosynthetic pigments, increasing antioxidant enzyme activity, and facilitating Fe reduction. Additionally, it increased the resistance of apple calli to Fe deficiency stress by enhancing Fe reduction and elevating the activity of antioxidant enzymes. For example, under Fe deficiency stress, the proline (Pro) contents of the overexpression lines (OE-2, OE-5, OE-6) were 26.18 mg·g⁻¹, 26.13 mg·g⁻¹, and 26.27 mg·g⁻¹, respectively, which were 16.98%, 16.76%, and 17.38% higher than the proline content of 22.38 mg·g⁻¹ in the wild-type lines, respectively. To summarize, a functional analysis of tobacco plants and apple calli displayed that WRKY69 TF serves as a positive regulator under Fe deficiency stress, which provides candidate genetic resources for cultivating apple rootstocks or varieties with strong stress (Fe deficiency) resistance. Full article

Soil compaction is a critical challenge in perennial fruit production, limiting root growth, water infiltration, and nutrient uptake—factors essential for climate-resilient and sustainable orchard systems. In subtropical Asian pear (Pyrus pyrifolia Nakai) orchards under the annual top-working system, intensive machinery traffic exacerbates subsurface hardpan formation and tree performance. This study evaluated the effectiveness of pneumatic subsoiling, a minimally invasive method using high-pressure air injection, in alleviating soil compaction without disturbing orchard surface integrity. Four treatments varying in radial distance from the trunk and pneumatic application were tested in a mature orchard in central Taiwan. Pneumatic subsoiling 120 cm away from the trunk significantly reduced soil penetration resistance by 15.4% at 34 days after treatment (2,302,888 Pa) compared to the control (2,724,423 Pa). However, this reduction was not sustained at later assessment dates, and no significant improvements in vegetative growth, fruit yield, and fruit quality were observed within the first season post-treatment. These results suggest that while pneumatic subsoiling can modify subsurface soil physical conditions with minimal surface disturbance, its agronomic benefits may require longer-term evaluation under varying moisture and management regimes. Overall, this study highlights pneumatic subsoiling may be a potential low-disturbance strategy to contribute to longer-term soil physical resilience. Full article

Annona neoinsignis H. Rainer (Annonaceae) is a tree native to the Amazon rainforest. Its fruits are also suitable for human consumption in their natural state or are processed to make desserts. In this work, we characterized the chemical composition of the essential oil (EO) from the leaves of A. neoinsignis and evaluated its anti-liver-cancer potential via in vitro and in vivo approaches. Chemical composition analysis revealed β-elemene, (E)-caryophyllene, germacrene D, and germacrene B as the main constituents. The EO had IC₅₀ values ranging from 12.28 to 37.50 μg/mL for B16-F10 cells and MCF-7 cells, whereas an IC₅₀ value of >50 μg/mL was found for noncancerous MRC-5 cells. DNA fragmentation, YO-PRO-1 staining, and loss of mitochondrial transmembrane potential were detected in EO-treated HepG2 cells, indicating the induction of apoptosis. Significant in vivo growth inhibition of 53.7% was observed in mice bearing HepG2 cell xenografts treated with EO at a dosage of 40 mg/kg. These data suggest that EO from A. neoinsignis leaves is a drug source for liver cancer. Full article

Ailanthus altissima (AA) is an invasive tree species rapidly spreading worldwide, colonizing both urban and agricultural or forestry environments. This three-year study aimed to assess its effects on the growth and yield traits of the Koroneiki olive cultivar under co-cultivation in pots, combined with two irrigation regimes, full and deficit irrigation (60% of full). Within each irrigation regime, olive trees were grown either in the presence or absence (control) of AA. The trial evaluated several parameters, including vegetative growth, yield traits, and oil quality characteristics. Co-cultivation with AA had no significant impact on tree growth after three years, though it significantly reduced oil content per fruit. Antioxidant capacity of the oil improved under deficit irrigation, while AA presence did not significantly affect it, except for an increase in o-diphenol concentration. Neither the fatty acid profile nor squalene levels were significantly influenced by either treatment. Fruit weight and color were primarily affected by deficit irrigation. During storage, olive oil quality declined significantly, with pre-harvest treatments (presence or absence of AA and full or deficit irrigation regime) playing a critical role in modulating several quality parameters. In conclusion, the presence of AA near olive trees did not substantially affect the key quality indices of the olive oil, which remained within the criteria for classification as extra virgin. Full article

Accurate acquisition of the phenotypic information of trunk-shaped fruit trees plays a crucial role in intelligent orchard management, pruning during dormancy, and improving fruit yield and quality. However, the precise segmentation of trunks and branches remains a significant challenge, limiting the accurate measurement of phenotypic parameters and high-precision pruning of branches. To address this issue, a novel adaptive cuboid regional growth segmentation algorithm is proposed in this study. This method integrates a growth vector that is adaptively adjusted based on the growth trend of branches and a growth cuboid that is dynamically regulated according to branch diameters. Additionally, an innovative reverse growth strategy is introduced to enhance the efficiency of the growth process. Furthermore, the algorithm can automatically and effectively identify the starting and ending points of growth based on the structural characteristics of fruit tree branches, solving the problem of where to start and when to stop. Compared with PointNet++, PointNeXt, and Point Transformer, ACRGS achieved superior performance, with F₁-scores of 95.75% and 96.21% and mIoU values of 0.927 and 0.933 for apple and cherry trees. The results show that the method enables high-precision and efficiency trunk–branch segmentation, providing data support for fruit tree phenotypic parameter extraction and pruning. Full article

This study addressed a significant and relevant issue, specifically the production of high-quality fruit planting material linked to an economically viable nursery operation. The process considered both the pedo-climatic conditions of the region where the fruit planting material was cultivated and the technological elements utilized. The objective of this research was to gather information regarding the necessity and effectiveness of implementing localized irrigation for plum trees in the nursery in the context of various fertilization treatments. It also aimed to investigate the variations in leaf area among Cacanska Lepotica and Stanley plum cultivars subjected to various irrigation (non-irrigated control, 10 mm, 20 mm, and 30 mm) and fertilization (unfertilized control, N₈P₈K₈, N₁₆P₁₆K₁₆, and N₂₄P₂₄K₂₄) methods. The study was conducted within a private nursery situated in the northwest region of Romania using a 4 × 2 × 4 split-split-plot design with five replications. This research took place in the summer of 2024, in the second field of the nursery during the growth stage of grafted trees. The implementation of various NPK fertilization methods (8%, 16%, and 24%) led to enhancements in leaf surface developments (increased by 6.53–16.14% compared to the control). The application of fertilization ranging from 8 to 16% and subsequently from 16 to 24% was effectively absorbed by the plum trees, resulting in a substantial growth of 180–226 cm². Irrigation with 30 mm generated significant increases in the leaf area of 4.42–14.27% compared to the control. To obtain optimal yields of grafted trees, it is advisable to utilize a combination of irrigation and NPK fertilization. To promote the appropriate growth and development of the trees, it is essential to monitor the soil moisture levels and to implement irrigation during times of water shortage when the trees exhibit heightened water usage. The research findings indicated that both cultivars experienced similar advantages from 24% NPK fertilization and 30 mm of irrigation; therefore, the implementation of the aforementioned technological elements is strongly recommended. Full article

Plants dynamically regulate ions in the tree to defend against abiotic stresses such as drought and saline-alkali, However, it is not clear how ‘Junzao’ jujube regulates ions to maintain a normal life cycle under saline-alkali stress. Therefore, in this study, the roots of 10-year old steer jujube trees were watered using a saline and alkaline gradient solution simulating the main salt (NaCl) and alkali (NaHCO₃) of Aral with NaCl:NaHCO₃ = 3:1 gradient of 0, 60, 180, and 300 mM, and three jujube trees with uniform growth were taken as samples in each treatment plot, and the ion contents of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and carbon (C) in each organ of the fruit at the dot red period (S1) and full-red period (S2) were determined, in order to elucidate the relationship between physiological adaptation mechanisms of saline-alkali tolerance and the characteristics of mineral nutrient uptake and utilisation in jujube fruit. The results showed that under saline-alkali stress, Na was stored in large quantities in the roots, Ca and Mg in the perennial branches at S1, Na and Fe in the leaves at S2, and K, Mg and Mn in the perennial branches. There was no significant difference in the distribution of C content in various organs of ‘Junzao’. Compared with CK (0 mM), under salinity stress, the K content in the leaves was significantly reduced at S1 and S2, and the K/Na ratios remained > 1.0. At S2, under medium and high concentrations of saline-alkali stress (180–300 mM), the K/Na is less than 1, and the ionic homeostasis was disrupted, and the leaves die and fall off, and the Na is excreted from the body. The selective transport coefficients SK/Na, SCa/Na and SMg/Na from root to leaf showed a downward trend at S1, but still maintained positive transport capacity. At S2, this stage is close to leaf fall, the nutrient transport coefficient is less than 1, and a large amount of nutrients are returned to the perennial branches and roots occurred. These results indicated that the mechanism of nutrient regulation and salt tolerance in jujube trees was different at different growth stages. Full article

The chlorophyll content is an important index reflecting the growth status and nutritional level of plants. The rapid, accurate and nondestructive monitoring of the SPAD content of apple trees can provide a basis for large-scale monitoring and scientific management of the growth status of apple trees. In this study, the canopy leaves of apple trees at different growth stages in the same year were taken as the research object, and remote sensing images of fruit trees in different growth stages (flower-falling stage, fruit-setting stage, fruit expansion stage, fruit-coloring stage and fruit-maturing stage) were acquired via a DJI MAVIC 3 multispectral unmanned aerial vehicle (UAV). Then, the spectral reflectance was extracted to calculate 15 common vegetation indexes as eigenvalues, the 5 vegetation indexes with the highest correlation were screened out through Pearson correlation analysis as the feature combination, and the measured SPAD values in the leaves of the fruit trees were gained using a handheld chlorophyll meter in the same stages. The estimation models for the SPAD values in different growth stages were, respectively, established through five machine learning algorithms: multiple linear regression (MLR), partial least squares regression (PLSR), support vector regression (SVR), random forest (RF) and extreme gradient boosting (XGBoost). Additionally, the model performance was assessed by selecting the coefficient of determination (R²), root mean square error (RMSE) and mean absolute error (MAE). The results show that the SPAD estimation results vary from stage to stage, where the best estimation model for the flower-falling stage, fruit-setting stage and fruit-maturing stage is RF and those for the fruit expansion stage and fruit-coloring stage are PLSR and MLR, respectively. Among the estimation models in the different growth stages, the model accuracy for the fruit expansion stage is the highest, with R² = 0.787, RMSE = 0.87 and MAE = 0.644. The RF model, which outperforms the other models in terms of the prediction effect in multiple growth stages, can effectively predict the SPAD value in the leaves of apple trees and provide a reference for the growth status monitoring and precise management of orchards. Full article

Chlorophyll content is a critical indicator of the physiological status and fruit quality of pear trees, with Soil Plant Analysis Development (SPAD) values serving as an effective proxy due to their advantages in rapid and non-destructive acquisition. However, current remote sensing-based SPAD retrieval studies are primarily limited to single phenological stages or rely on a narrow set of input features, lacking systematic exploration of multi-temporal feature fusion and comparative model analysis. In this study, pear leaves were selected as the research object, and Sentinel-2 remote sensing data combined with in situ SPAD measurements were used to conduct a comprehensive retrieval study across multiple growth stages, including flowering, fruit-setting, fruit enlargement, and maturity. First, spectral reflectance and representative vegetation indices were extracted and subjected to Pearson correlation analysis to construct three input feature schemes. Subsequently, four machine learning algorithms—K-Nearest Neighbors (KNN), Random Forest (RF), Support Vector Machine (SVM), and an Optimized Integrated Algorithm (OIA)—were employed to develop SPAD retrieval models, and the performance differences across various input combinations and models were systematically evaluated. The results demonstrated that (1) both spectral reflectance and vegetation indices exhibited significant correlations with SPAD values, indicating strong retrieval potential; (2) the OIA model consistently outperformed individual algorithms, achieving the highest accuracy when using the combined feature scheme; (3) among the phenological stages, the fruit-enlargement stage yielded the best retrieval performance, with R² values of 0.740 and 0.724 for the training and validation sets, respectively. This study establishes a robust SPAD retrieval framework that integrates multi-source features and multiple models, enhancing prediction accuracy across different growth stages and providing technical support for intelligent orchard monitoring and precision management. Full article

Dothistroma needle blight (DNB) is one of the most significant diseases of conifers, causing premature defoliation, growth reduction, and, in extreme cases, mortality. Histological analysis was undertaken on inoculated seedlings of three different seed sources of Pinus sylvestris L. to investigate the process of infection and degradation of needle tissue on this host species. Seedlings were inoculated using a single spore isolate of Dothistroma septosporum (Doroguine) M. Morelet (D636) from northern Scotland. Mesophyll degradation in the needles occurred by four weeks after inoculation; collapse of mesophyll, bundle sheath tissues, and tracheids by five weeks; and eruption of fruiting bodies in near proximity to stomatal openings by six weeks. Significantly greater collapse of mesophyll during the early stages of infection occurred in the Austrian provenance compared with the United Kingdom provenance, although in the later stages of infection, this difference disappeared. Furthermore, disease severity, assessed as the proportion of needles with D. septosporum conidiomata on each tree, was not significantly different between seed sources. Full article

Proximal plant-based monitoring provides high-resolution data about trees, leading to more precise orchard management and in-depth knowledge about tree physiology. The present work focuses on continuous real-time monitoring of olive cv. ‘Ascolana tenera’ over hourly intervals during the third stage of fruit growth (mesocarp cell expansion) under mild water stress conditions (ψStem above −2 MPa). This is achieved by mounting dendrometers on the root, trunk, branch, and fruit to assess and model the behavior of each organ. The diameter variation in each organ over different time intervals (daily, two-weeks, and throughout the entire experiment), as well as their hysteretic patterns relative to each other and vapor pressure deficit, are demonstrated. The results show different correlations between various organs, ranging from very weak to strongly positive. However, the trend of fruit versus root consistently shows a strong positive relationship throughout the entire experiment (R² = 0.83) and a good one across various two-week intervals (R² ranging from 0.54 to 0.93). Additionally, different time lags in dehydration and rehydration between organs were observed, suggesting that the branch is the most reactive organ, regulating dehydration and rehydration in the tree. Regarding the hysteretic pattern, different rotational patterns and characteristics (shape) were observed among the organs and in relation to vapor pressure deficit. This research provides valuable insight into flow dynamics within a tree, models plant water relations and time lags in terms of water storage and transport, and could be implemented for precise olive tree water status detection. Full article

Orchard cover crops enhance the local microclimate and soil fertility, serving as an eco-friendly, efficient management practice. However, the effects of different cultivated species and planting patterns on plant growth and soil properties remain unclear. In this study, we hypothesized that different cultivated species and planting patterns would differently affect root growth and soil biochemistry. Therefore, the root growth, soil nutrients, and soil metabolites in an orchard planted with Vulpia myuros, Vicia villosa, Orychophragmus violaceus, and Brassica campestris in either a tree-disk or inter-row patterns were conducted. The results indicated that the tree-disk pattern promoted root development. This increase in below-ground biomass contributed to changes in soil nutrient dynamics, with a significant biomass accumulation observed for Orychophragmus violaceus. While the inter-row pattern improved soil aeration and was conducive to aboveground plant growth. The tree-disk pattern with Vicia villosa and Brassica campestris increased the total phosphorus (TP) and total potassium (TK) in the 0–10 cm layer. The soil NH₄⁺-N and NO₃⁻-N contents were higher under the tree-disk pattern than under the inter-row pattern with Brassica campestris, whereas the opposite effect was seen with Vulpia myuros. Overall, we recommend planting Orychophragmus violaceus in a tree-disk pattern and Vulpia myuros in an inter-row pattern to promote plant biomass accumulation and soil nutrient increases in orchards. Our study provides a basis for the selection of orchard-cultivated species and planting patterns to promote the sustainable development of the fruit industry. Full article

The structural characteristics of hickory trees exhibit a significant correlation with their fruit yield. As a distinctive high-quality nut of Zhejiang Province, hickory is a unique high-end dry fruit and woody oil plant in China. However, the long growth cycle and extended maturation period make their management particularly challenging, especially in the absence of high-precision 3D digital models. This study aims to optimize hickory tree management and identify trees with the most optimal structural features. It employs gradient-boosted machine learning modeling based on 23 key tree characteristics, transforming the experiential knowledge of forest farmers into quantifiable parameters. The consensus model achieved an LOOCV average accuracy of 87%, a training set accuracy of 100%, and a test set accuracy of 78%. Through this approach, three structural parameters that significantly impact the hickory tree were identified: the number of branches, the total length of all branches, and the crown base height from the ground. These parameters were used to select trees with superior structural traits. Furthermore, a novel method based on distance metrics was developed to assess the structural similarity of trees. This research not only highlights the importance of incorporating tree structural characteristics into forest management practices but also demonstrates how modern technological tools can enhance the productivity and economic returns of hickory forests. Through this integration, both the sustainability and economic viability of hickory forests are improved. Full article