Search Results (152)

Climate change is modifying ecoclimatic conditions, including temperature, solar radiation, and water availability, with significant impacts on grapevine phenology, berry ripening, and the polyphenolic composition of grapes cultivated in temperate regions. The influence of different meteorological conditions during ripening on the polyphenolic composition of Grignolino grapes grown in a hilly environment was investigated. Grapes were collected, over three vintages, from three vineyards differing in their vine age and bunch microclimate due to having different vineyard aspects. We considered a comparable berry weight, moderate rainfall and cool conditions before veraison, followed by a warm and dry pre-harvest stage that enhanced the phenolic and especially the anthocyanin index in the grapes (e.g., 360 mg kg⁻¹ in 2021 versus 260 mg kg⁻¹ in 2020). Intense heat and dry conditions reduced the berry weight, leading to an increase in both flavonols and hydroxycinnamoyl tartaric acids, particularly in the younger, southwest-exposed vineyard. Older vines with a cooler aspect were the most resilient to different meteorological conditions, while young vines showed greater variability over the years. The phenolic composition was strongly influenced by the intensity and the timing of thermal stress, and eventually on limited water availability during ripening; it also depended on the vine age and the vineyard microclimate determined by the hillside aspect. This knowledge may support adaptive strategies to preserve grape quality under climate change. Full article

Accurate fruit detection and counting are fundamental requirements in the development of reliable computer vision applications for yield estimation. This work was conceived to provide farmers with a farmer-friendly approach for automatic grape bunch detection. This study exploits the free demo version of the Roboflow 3.0 platform to train five state-of-the-art computer vision models with RGB images of white and red grape bunches, acquired with a smartphone in the field, and compares their performance. The results were evaluated both quantitatively, in terms of precision, recall, and AP@50 calculated on the validation set, and qualitatively on the test set. The models that achieved the best performances, also in the presence of overlapping clusters, were Roboflow 3.0 Object Detection and YOLOv11, reaching precisions of 86.6% and 88%, respectively, for the detection of white bunches, and of 85.7% and 89.9% for red bunches. This study highlights the possibility of developing highly accurate computer vision models for table grape bunch detection using the Roboflow platform, offering an accessible and user-friendly tool for non-expert users, including farmers. Full article

Orchard crops generate substantial quantities of diverse biomass each year, with grapevines being among the most economically significant species worldwide. Considering the scale of this biomass, there is a growing need to explore rational strategies for its utilisation, for example, for energy production or other value-added applications. Such approaches may contribute to improving resource efficiency and reducing the environmental burden associated with agricultural waste. The aim of this study was to examine the energy potential of woody post-production waste from wine processing, with particular emphasis on grape stems of four cultivars—Chardonnay, Riesling, Merlot, and Zweigelt—grown in two contrasting climatic regions: south-eastern Poland and Moravia (Czech Republic). The results demonstrated that both the grape variety and cultivation site significantly influenced the majority of bunch biometric traits, including bunch and berry weight, berry number, and stem dimensions. A moderately warm climate promoted the development of larger and heavier bunches as well as more robust stems across all examined cultivars. Energy analyses indicated that Zweigelt stems produced under moderately warm conditions and Chardonnay stems from a temperate climate exhibited the most favourable combustion properties. Nonetheless, certain constraints were identified, such as increased ash (12.20%) and moisture content (11.51%) in Chardonnay grown in warmer conditions, and elevated CO and CO₂ emissions observed for Zweigelt (1333.26 kg·mg⁻¹). Overall, the findings confirm that grape stems constitute a promising local source of bioenergy, with their energy performance determined predominantly by varietal characteristics and climatic factors. Their utilisation aligns with circular-economy principles and may help reduce the environmental impacts associated with traditional viticultural waste management. Full article

This study evaluated the effects of late pruning and late apical leaf removal on grapevine phenology, fruit composition, yield parameters, xylem sap carbohydrate content, and grape skin polyphenol levels over two consecutive vintages (2022 and 2023). As expected, delayed pruning shifted the phenological stages, with more pronounced delays observed in 2022 than in 2023. However, by August, all the treatments had reached the berry-softening stage, indicating a convergence in ripening. The grape juice composition showed no significant differences in sugar content in 2022; however, in 2023, the °Brix was notably reduced in control vines subjected to late apical defoliation. The titratable acidity and pH remained stable across treatments and years, while the malic acid concentrations were consistently higher in the late-pruned treatments, particularly LP2 (late pruning 2 was performed when the control vines had reached the eight-leaves-folded development stage). Late pruning significantly reduced the yield and bunch size, especially for the 2023 LP2 treatment. In contrast, late apical defoliation had minimal impact on the yield components. Vegetative growth, as assessed by cane diameter and weight, also declined under late pruning. Despite this, the xylem sap analysis revealed no significant changes in the glucose, fructose, or myo-inositol levels, suggesting that the carbohydrate reserves remained unaffected. Notably, LP2 consistently resulted in the highest total polyphenol content in the grape skins across both years, indicating enhanced phenolic maturity. Although the polyphenol concentrations were generally higher in 2023, the treatment effects varied more widely, likely due to the differing environmental conditions. These findings suggest that late pruning—particularly LP2—can be a valuable tool for improving grape phenolic quality, albeit at the cost of reduced yield and vine vigor. This study highlights the importance of site- and season-specific canopy management strategies in balancing fruit quality with productivity under variable climatic conditions. Full article

Climate change poses a major challenge for Mediterranean viticulture by accelerating ripening and reducing grape yield and quality. This study evaluated the synergistic effect of two adaptation strategies—non-positioned vegetation training (Sprawl) and foliar kaolin application—on the agronomic and oenological performance of Syrah cv. under semi-arid conditions over two consecutive seasons. Agronomic traits, bunch microclimate, and volatile composition of wines were determined. The combination of Sprawl and kaolin reduced bunch temperature by up to 2 °C, improved vine balance, and maintained optimal acidity and colour intensity. Wines from this treatment exhibited higher concentrations of esters and terpenes, generating more pronounced fruity, floral, and citrus aromas. Multivariate analysis of aroma series revealed clear differences between treatments and vintages, with 2025 showing stronger aromatic distinctions. Heatmap clustering confirmed that vintage was the main differentiating factor, followed by training system. These findings highlight the potential of integrating simple canopy management with reflective particle films to improve grape and wine quality under future Mediterranean conditions. Full article

Microbial inoculants, as a new type of product that combines economic efficiency with ecological sustainability, play an important role in promoting plant growth and development, increasing crop yields, and enhancing plant resistance to abiotic stress. This study used the wine grape cultivar (Vitis vinifera ‘Pinot Noir’) as experimental material to systematically investigate the effects of microbial inoculants on the soil–leaf–fruit system during the late growth stage of grapes under salt stress conditions (200 mM NaCl). This study analyzed the regulatory effects of microbial inoculants on soil physicochemical properties, leaf physiological and biochemical characteristics, as well as fruit yield and quality. The results showed that salt stress significantly inhibited the growth of Pinot Noir grapes. However, the application of microbial inoculants effectively alleviated the negative effects of salt stress. By enhancing the plant’s antioxidant defense capacity and regulating physiological metabolic pathways such as osmotic balance, the inoculants significantly mitigated the inhibitory effect of salt stress on fruit development. Notably, the S+JH treatment group demonstrated particularly outstanding results, with hundred-berry weight, single-bunch weight, and yield per plant increasing significantly by 15.96%, 12.47%, and 28.93%, respectively, compared to the salt stress group (S). Additionally, this treatment also stabilized free amino acid content and suppressed excessive organic acid synthesis. This study provides new technical insights into the application of microbial inoculants for saline-alkali land improvement and stress-resistant cultivation of horticultural crops such as grapes, holding significant practical value for promoting the sustainable development of the grape industry in saline-alkali regions. Full article

A study was carried out to identify the filamentous fungi and yeasts present in rotten wine grapes from two subzones of the Southern oasis of Mendoza winegrowing region, to assess the occurrence of tenuazonic acid (TA), a mycotoxin produced by the Alternaria genus, and to evaluate the wine spoilage potential of the associated yeasts in vitro and during microvinifications. The main fungal genera present were Alternaria (69.3%), followed by Aspergillus (16.8%), Penicillium (9.3%), and Cladosporium (4.6%), while the dominant yeast species Metschnikowia pulcherrima (23.1%), Aureobasidium pullulans (20.2%) and Hanseniaspora uvarum (13.0%) were followed by H. vineae (11.6%), Zygosaccharomyces bailii (10.4%), and H. guilliermondii (9.2%). Additionally, 94.1% of the rotten samples were contaminated with TA, with the highest level found in the Cabernet Sauvignon variety. No geographic association was found in the incidence of the different fungal genera or yeast species, nor in the occurrence of TA. Almost all of the tested yeasts produced H₂S, the majority of the Hanseniaspora strains produced acetic acid, and only one M. pulcherrima strain produced off-flavours in in vitro tests. Wines co-fermented with H. uvarum L144 and S. cerevisiae showed higher volatile acidity and lower fruity aroma and taste intensity. Therefore, processing bunch rot could pose a toxicological and microbiological risk to winemaking due to the high incidence of Alternaria and TA, as well as the potential of the associated yeasts to spoil wine. Full article

This study investigated the impact of berry and cluster thinning on the organoleptic and chemical quality of red wines produced with no-sulfites-added production, using ‘Monastrell’ grapes cultivated under organic viticulture. The experiment was conducted in a commercial vineyard in Murcia (Spain), applying three treatments: control, bunch reduction (BR), and berry thinning (BT). Grapes were vinified under identical conditions, and the resulting wines were analyzed after three months and five years of storage. Physicochemical parameters, volatile organic compounds (VOCs), and sensory profiles were evaluated. Thinning treatments significantly increased alcohol content, reducing sugars, polyphenol index, and the concentration of key aromatic compounds. Sensory analysis revealed that wines from thinned grapes exhibited more intense toasted, vegetal, and fruity notes, and presented greater color stability and fewer defects over time. Notably, only the control wine developed Brettanomyces-related off-flavors after five years. Consumer preference tests confirmed higher acceptance of BR and BT wines, based particularly on color, fruity aroma, and aftertaste. These findings suggested that thinning practices, especially bunch thinning, offer a cost-effective strategy to improve wine quality and stability in no-sulfites-added winemaking, reducing the risk of spoilage and enhancing consumer satisfaction. Full article

For fruit harvesting robots, rapid and accurate detection of fruits and picking points is one of the main challenges for their practical deployment. Several fruits typically grow in clusters or bunches, such as grapes, cherry tomatoes, and blueberries. For such clustered fruits, it is desired for them to be picked by bunches instead of individually. This study proposes utilizing a low-cost off-the-shelf RGB-D sensor mounted on the end effector and a lightweight improved YOLOv8-Pose neural network to detect cherry tomato bunches and picking points for robotic harvesting. The problem of occlusion and overlap is alleviated by merging RGB and depth images from the RGB-D sensor. To enhance detection robustness in complex backgrounds and reduce the complexity of the model, the Starblock module from StarNet and the coordinate attention mechanism are incorporated into the YOLOv8-Pose network, termed StarBL-YOLO, to improve the efficiency of feature extraction and reinforce spatial information. Additionally, we replaced the original OKS loss function with the L1 loss function for keypoint loss calculation, which improves the accuracy in picking points localization. The proposed method has been evaluated on a dataset with 843 cherry tomato RGB-D image pairs acquired by a harvesting robot at a commercial greenhouse farm. Experimental results demonstrate that the proposed StarBL-YOLO model achieves a 12% reduction in model parameters compared to the original YOLOv8-Pose while improving detection accuracy for cherry tomato bunches and picking points. Specifically, the model shows significant improvements across all metrics: for computational efficiency, model size (−11.60%) and GFLOPs (−7.23%); for pickable bunch detection, mAP50 (+4.4%) and mAP50-95 (+4.7%); for non-pickable bunch detection, mAP50 (+8.0%) and mAP50-95 (+6.2%); and for picking point detection, mAP50 (+4.3%), mAP50-95 (+4.6%), and RMSE (−23.98%). These results validate that StarBL-YOLO substantially enhances detection accuracy for cherry tomato bunches and picking points while improving computational efficiency, which is valuable for resource-constrained edge-computing deployment for harvesting robots. Full article

Reliable early-stage yield forecasts are essential in precision viticulture, enabling timely interventions such as harvest planning, canopy management, and crop load regulation. Since grape yield is directly related to the number and size of bunches, the early detection of inflorescences and bunches, carried out even before flowering, provides a valuable foundation for estimating potential yield far in advance of veraison. Traditional yield prediction methods are labor-intensive, subjective, and often restricted to advanced phenological stages. This study presents a deep learning-based approach for detecting grapevine inflorescences and bunches during early development, assessing how phenological stage and illumination conditions influence detection performance using the YOLOv11 architecture under commercial field conditions. A total of 436 RGB images were collected across two phenological stages (pre-bloom and fruit-set), two lighting conditions (daylight and artificial night-time illumination), and six grapevine cultivars. All images were manually annotated following a consistent protocol, and models were trained using data augmentation to improve generalization. Five models were developed: four specific to each condition and one combining all scenarios. The results show that the fruit-set stage under daylight provided the best performance (F1 = 0.77, R² = 0.97), while for inflorescences, night-time imaging yielded the most accurate results (F1 = 0.71, R² = 0.76), confirming the benefits of artificial lighting in early stages. These findings define optimal scenarios for early-stage organ detection and support the integration of automated detection models into vineyard management systems. Future work will address scalability and robustness under diverse conditions. Full article

Flavonoids play a crucial role in plant development, resistance, and the pigmentation of fruits and flowers. This study aimed to uncover the mechanism of flavonoid biosynthesis and fruit coloring in muscadine grapes. Two muscadine genotypes (Paulk and Supreme) were investigated via metabolomic and transcriptomic analysis during three developmental stages (bunch closure, veraison stage, and ripening stage). A total of 314 flavonoids were identified, with flavones and flavonols being the primary constituents. The contents of many differentially accumulated metabolites (DAMs) were higher at the veraison stage. The total anthocyanin content was upregulated during berry development, with the dominant type of anthocyanidin-3,5-O-diglucoside. Proanthocyanins accumulated higher levels in the ripening stage of Paulk than Supreme. Transcriptomic analyses revealed that over 46% of the DEGs exhibited higher expression levels in the bunch closure stage. Moreover, phenylalanine ammonia-lyase (PAL), cinnamyl 4-hydroxylase (C4H), and coumaryl CoA ligase (4CL) genes were upregulated during berry development, suggesting they promote second metabolites biosynthesis. The upregulation of dihydroflavonol 4-reductase (DFR) and leucoanthocyanin reductase (LAR) may related to the higher levels of PA in Paulk. Anthocyanidin synthase (ANS) and UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT) showed higher expression levels in the ripening stage, which may relate to the accumulation of anthocyanidins. This study provides comprehensive insights into flavonoid metabolism and berry coloration in Vitis rotundifolia. Full article

Bunch compactness (BC) is a complex, multi-trait characteristic that has been studied mostly in the context of wine grapes, with table grapes being scarcely considered. As these groups have marked phenotypic and genetic differences, including BC, the study of this trait is reported here using a genetically diverse collection of 116 Vitis vinifera L. cultivars and lines enriched for table grapes over two seasons. For this, 3D scanning-based morphological data were combined with ground measurements of 14 BC-related traits, observing high correlations among both approaches (R² > 0.90–0.97). The multivariate analysis suggests that the attributes ‘berries per bunch’, ‘berry weight and width’, and ‘bunch weight and length’ could be considered as the main descriptors for BC, optimizing evaluation times. Then, GWASs based on a set of 70,335 SNPs revealed that GBS analysis in this same population enabled the detection of several SNPs associated with different sub-traits, with a locus for ‘berries per bunch’ in chromosome (chr) 18 being the most prominent. Enrichment analysis of significant and frequent SNPs found simultaneously in several traits and seasons revealed the over-representation of discrete functions such as alpha-linolenic acid metabolism and glycan degradation. In summary, the utility of 3D automated phenotyping was validated for table grape backgrounds, and new SNPs and candidate genes associated with the BC trait were detected. The latter could eventually become a selection tool for grapevine breeding programs. Full article

Histone post-translational modifications (HPTMs) can affect gene expression by rearranging chromatin structure. Between these, histone methylation is one of the most studied in filamentous fungi, and different conserved domains coding for methyltransferase were found in Aspergillus spp. genomes. In this work, the role of the histone methyltransferases AcDot1 and AcRmtA in the mycotoxigenic fungus Aspergillus carbonarius was investigated, obtaining knockout or overexpression mutants through Agrobacterium tumefaciens-mediated transformation (ATMT). A. carbonarius is responsible for grape-bunch rot, representing the major source of ochratoxin A (OTA) contamination on grapes. In vivo conditions, the deletion of Acdot1 or AcrmtA resulted in upregulation of growth when the isolates were cultivated on a minimal medium. The influence of Acdot1 on the OTA biosynthesis was differently affected by culture conditions. On rich media, an increase in OTA accumulation was observed, while on minimal medium, lower OTA concentrations were reported. The deletion of AcrmtA always resulted in lower OTA accumulation. However, the expression of OTA biosynthesis genes was regulated by both histone methyltransferases. Of the six analyzed OTA genes, three of them showed altered expression in the knockout mutants, and otaB and otaR1 were common between both mutants. Furthermore, both AcDot1 and AcRmtA play a role in oxidative stress response, induced by 1 mM hydrogen peroxide, by modulating growth, conidiation and OTA biosynthesis. Neither the deletion nor the overexpression of the Acdot1 or AcrmtA affected virulence, while both the sporulation and OTA production were negatively affected in vivo by the deletion of AcrmtA. Full article

The objective of this work was to assess different concentrations of a novel formulation of 1-aminocyclopropane-1-carboxylic acid (ACC) on anthocyanin accumulation and color development, as well as on the physicochemical characteristics of the ‘Benitaka’ table grape grown in a subtropical region in two application forms. The trial was conducted on a commercial property located in a subtropical area in Brazil in 2022. Treatments included different concentrations of a new formulation containing 400 g kg⁻¹ of ACC, ranging from 0 to 125 g 100 L⁻¹, as well as a standard concentration of a formulation containing 100 g L⁻¹ of abscisic acid (S-ABA): 3.2 L ha⁻¹. The exogenous application of ACC was performed at the beginning of berry ripening (véraison), while that of S-ABA was performed twice: the first, at véraison, and the second, 7 days later. The concentration of total anthocyanins, berry color index, physicochemical characteristics, and sensory–visual analysis of color coverage of the bunches were evaluated weekly, while berry firmness was appraised at harvest. A single exogenous application of ACC or two applications of S-ABA resulted in daily increment rates that provided a high accumulation of total anthocyanins, as well as greater berry color development, regardless of the application method, directed to the canopy of the vines or only to the bunches. As a result, the new formulation of ACC at concentrations of 75 g to 100 g 100 L⁻¹ is a novel tool to stimulate the anthocyanins accumulation and berry color development in ‘Benitaka’ table grapes grown in subtropical regions without negative impact on bunches or vines. Full article

The cultivation of ‘Shine Muscat’ grapes is rapidly expanding in East Asia due to their desirable qualities and muscat flavor. Studies have revealed that storing these grapes at an controlled freezing-point temperature diminishes their muscat flavor, whereas storage at 10 °C preserves it. However, the impact of a higher storage temperature on the evolution of microbial communities remains unclear. This study aimed to analyze the mycobiota dynamics of ‘Shine Muscat’ grape bunches under different cold storage temperatures. A total of 1,892,842 and 1,643,200 sequences were obtained from berries and pedicels, identifying over 208 fungal genera from 6 phyla. Xylariaceae was the most abundant family, with a prevalence between 7.21% and 69.27% across all sample groups. The primary genera included Zygosporium, Cladosporium, Aspergillus, Acremonium, Podosordaria, Zasmidium, Penicillium, and Alternaria. Spoilage-related fungi varied with storage temperature, with Aspergillus, Penicillium, and Alternaria being dominant at 0 °C and Cladosporium, Aspergillus, Penicillium, and Alternaria being prevalent at 10 °C. The fungal profiles of berries and pedicels differed significantly, and storage temperature further influenced these variations. Our findings highlight distinct fungal diversity and spoilage patterns in ‘Shine Muscat’ grape bunches from the Nanning region compared to those grown in temperate areas, revealing the unique microbial evolution of grape bunches stored at different temperatures in Nanning. Full article