Search Results (134)

Grapevine trunk diseases, particularly those caused by Neofusicoccum parvum, represent a major threat to vineyard productivity and are increasingly difficult to control with conventional fungicides. Green synthesis of silver nanoparticles (AgNPs) using biocontrol fungi offers a promising alternative, but the factors governing the efficiency and bioactivity of biogenic nanoparticles remain poorly understood. Here, three Trichoderma species (T. harzianum, T. asperellum and T. virens) were evaluated as biological nanofactories for AgNP production. Cell-free fungal filtrates were used to synthesize AgNPs, which were characterized by UV–visible spectrophotometry, Dynamic Light Scattering (DLS) and transmission electron microscopy, while fungal redox metabolism was assessed using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays and HPLC profiling of extracellular metabolites. AgNPs were tested against two isolates of N. parvum in vitro. The Trichoderma strains differed markedly in nanoparticle yield, size and antifungal activity, with T. harzianum T0 producing the highest amounts of small, well-dispersed AgNPs that exerted a strong fungistatic effect on N. parvum. Nanoparticle production correlated with antioxidant capacity and the abundance of redox-active metabolites. Integration of these parameters into a Fungal Nanofactory Efficiency Index (FNEI) revealed that nanoparticle bioactivity depends on both dose and biological origin. These results demonstrate that fungal metabolism is a key determinant of biogenic nanoparticle performance and identify Trichoderma as a platform for sustainable nanotechnology-based control of grapevine trunk pathogens. Full article

Grapevine trunk diseases, particularly Botryosphaeria dieback, pose a major threat to vineyard sustainability, a risk that is further intensified by climate variability and increasing environmental stress. This study evaluated pathogenicity and bacterial biocontrol efficacy against Neofusicoccum parvum and Diplodia seriata under vineyard conditions, analyzing the combined effects of cultivar (Vitis vinifera L. cv. Cabernet Sauvignon and Sauvignon Blanc), tissue type (young shoots and lignified arms), and phenological season (autumn/winter and spring/summer). Pathogenicity assays revealed clear tissue-age specialization: N. parvum was more aggressive in young shoots, whereas D. seriata caused the most severe vascular lesions in lignified wood. Seasonality further modulated disease expression, with higher lesion development during spring/summer, particularly for N. parvum in young shoots, while D. seriata maintained high aggressiveness in lignified tissues across both seasons. Berry assays provided a rapid initial assessment of isolate virulence but did not fully reflect pathogen behavior in woody tissue under field conditions. Biological treatments using native bacterial strains (Pseudomonas sp. AMCR2b, GcR15a, and Rhodococcus sp. PU4) significantly reduced lesion severity in V. vinifera under field conditions, although efficacy varied by tissue type and season. Biocontrol effects were generally more stable in lignified arms, and under high disease pressure, only the most robust strains maintained consistent protection, in some cases matching or surpassing the efficacy of the fungicide tebuconazole. These results show that both pathogenicity and biocontrol performance against Botryosphaeria dieback in V. vinifera under field conditions are strongly influenced by tissue type and season, supporting bacterial biocontrol as a sustainable component of integrated disease management in vineyards. Full article

Botrytis cinerea, the causal agent of grey mold in grapevine, remains one of the most economically important pathogens in viticulture and a key target for sustainable biocontrol strategies. This study evaluated the antagonistic potential of seven Trichoderma isolates (T1–T7), collected from the rhizosphere of grapevine in Morocco, using a combination of in vitro and in planta assays designed to capture multiple direct and indirect modes of action. The isolates exhibited variable levels of antagonism through competition, volatile organic compounds, extracellular metabolites, and elicitation responses. Preliminary in planta assays on detached grape berries further demonstrated that all selected isolates reduced lesion development, with preventive applications yielding the strongest protection. Overall, the study highlights the complementary and strain-specific mechanisms underlying Trichoderma & B. cinerea interactions and underscores the importance of isolate selection and application timing for the development of effective and environmentally friendly grey mold management strategies. These findings provide a mechanistic basis for the future evaluation of promising isolates under vineyard conditions. Full article

Reducing the alcohol content of wines has received increasing attention, and various strategies have been proposed for this aim. In this study, non-Saccharomyces yeasts isolated from Uruguayan vineyards were screened to identify strains with low ethanol production for use in mixed cultures. Twenty-six strains belonging to six species were evaluated, considering key oenological parameters such as ethanol and glycerol production, glucose and fructose consumption, and absence of organoleptic defects. Based on these criteria, three strains from two genera were selected: Starmerella bacillaris (Sb1 and Sb2) and Metschnikowia fructicola (Mf2). In pure cultures, Starmerella bacillaris showed high sugar consumption along with high glycerol production. Subsequently, co-inoculation and sequential inoculation conditions were tested by combining the selected strains with commercial Saccharomyces cerevisiae (Sc). With Mf2 + Sc sequential inoculation, high sugar consumption, increased glycerol production, and a significant reduction in ethanol were observed compared to the control. For Starmerella bacillaris, only Sb1 achieved consistent alcohol reductions in sequential strategies. With co-inoculation, both strains reduced ethanol by 0.2–1% v/v, although only Sb1 showed complete sugar depletion. Overall, the results demonstrate a marked dependence of fermentation behavior on the strain and highlight the importance of studying biocompatibility and inoculation strategy in mixed cultures. Full article

The Yantai region in China, despite its ideal viticultural conditions, faces a challenge in producing white wines with distinct regional typicity. This study explores the potential of indigenous yeast strains—specifically, the Hanseniaspora uvarum H30 and Saccharomyces cerevisiae YT13, both isolated and identified from the Yantai vineyard environment—to enhance the aroma profiles and overall quality of white wines from this region. Italian Riesling and Petit Manseng grapes were fermented with two commercial Saccharomyces cerevisiae strains (EC1118 and Tropical/X16) and a sequential inoculation of the locally sourced Hanseniaspora uvarum H30 (with high β-glucosidase activity) followed by S. cerevisiae YT13. The results showed that sequential inoculation with H30 + YT13 significantly enhanced the concentration of key ester compounds and uniquely increased terpene levels. Notably, valuable terpenes such as farnesol and nerolidol were exclusively detected in the H30 + YT13 group for Italian Riesling. Sensory analysis confirmed that these chemical changes translated into higher scores for floral and fruity attributes in the sequentially inoculated wines. These findings demonstrate that sequential inoculation with indigenous yeasts effectively enhances the aromatic complexity and varietal typicity of white wines from Yantai, providing a promising strategy for developing wines with stronger regional identity. Full article

Gray mold, caused by Botrytis cinerea Pers. Fr. (teleomorph: Botryotinia fuckeliana), is a major disease affecting Moroccan vineyards. However, limited information is available on the natural populations of this pathogen. In this study, 82 single-spore isolates collected from vineyards in two major wine-growing regions were evaluated for phenotypic, physiological, and molecular variability. The isolates exhibited differences in morphotypes, conidial size, and sclerotia production on PDA medium. Temperature significantly affected mycelial growth rate (mm d⁻¹). All isolates were virulent on grapevine leaves, showing varying levels of aggressiveness. Among the representative isolates, 20 were heterothallic and 2 were homothallic. Mating-type analysis revealed that 12% belonged to MAT1-1 and 75% to MAT1-2. Transposable element genotyping showed that the population was composed of 41.7% transposa, 29.2% vacuma, 16.7% Flipper-only, and 12.5% Boty-only. This work represents the first report on genotypic variation in B. cinerea populations from Moroccan vineyards. The findings provide new insights into the morphenotypic and genetic diversity of the pathogen and may support the development of improved strategies for disease management. Full article

The rapid and reliable acquisition of canopy-related metrics is essential for improving decision support in viticultural management, particularly when monitoring individual vines for targeted interventions. This study presents a spatially explicit workflow that integrates Uncrewed Aerial System (UAS) imagery, 3D point-cloud analysis, and Object-Based Image Analysis (OBIA) to detect and monitor individual grapevines throughout the growing season. Vines are identified directly from 3D point clouds without the need for prior training data or predefined row structures, achieving a mean Euclidean distance of 10.7 cm to the reference points. The OBIA framework segments vine vegetation based on spectral and geometric features without requiring pre-clipping or manual masking. All non-vine elements—including soil, grass, and infrastructure—are automatically excluded, and detailed canopy masks are created for each plant. Vegetation indices are computed exclusively from vine canopy objects, ensuring that soil signals and internal canopy gaps do not bias the results. This enables accurate per-vine assessment of vigour. NDRE values were calculated at three phenological stages—flowering, veraison, and harvest—and analyzed using Local Indicators of Spatial Association (LISA) to detect spatial clusters and outliers. In contrast to value-based clustering methods, LISA accounts for spatial continuity and neighborhood effects, allowing the detection of stable low-vigour zones, expanding high-vigour clusters, and early identification of isolated stressed vines. A strong correlation (R² = 0.73) between per-vine NDRE values and actual yield demonstrates that NDRE-derived vigour reliably reflects vine productivity. The method provides a transferable, data-driven framework for site-specific vineyard management, enabling timely interventions at the individual plant level before stress propagates spatially. Full article

Viticulture in the Iberian Peninsula is increasingly threatened by climate change, particularly rising temperatures and prolonged droughts. This study evaluates the ability of the De Martonne Index (DMI), a simple climatic aridity index based solely on temperature and precipitation, to serve as a proxy for vineyard health over a 30-year period (1993–2022). Vineyard health was assessed using the Vegetation Health Index (VHI), derived from satellite remote sensing data. DMI values were computed from bias-corrected ERA5-Land data, and VHI composites were generated from NOAA satellite imagery. Vineyard-specific outputs were isolated using land cover datasets, and a contingency analysis compared drought classifications from both indices. Results show a strong spatio-temporal correspondence between low DMI values and reduced VHI, with agreement rates for severe/extreme drought conditions reaching up to 56% under the most restrictive DMI thresholds. In the analyzed period, years such as 1995, 1997, 2005, 2009, and 2012, showed over 20% of vineyard areas affected by moderate-to-severe/extreme drought. The spatial analysis revealed that northern and northwestern regions of the peninsula experienced less drought stress, while central and southern areas were more frequently affected. This approach demonstrates that the DMI alone can provide a reliable assessment of vineyard health, potentially enabling its direct use with seasonal forecasts, which are generally available for temperature and precipitation, to anticipate drought impacts and support adaptation in viticulture. The proposed methodology is scalable and transferable to other crops and regions, serving as a tool for climate adaptation strategies in viticulture. Full article

Despite advances in precision irrigation, no systematic review has yet integrated the roles of remote sensing, agro-meteorological data, and wireless sensor networks in high-value, water-sensitive crops such as mango, avocado, and vineyards. Existing research often isolates technologies or crop types, overlooking their convergence and joint performance in the field. This review fills that gap by examining how these tools estimate crop water demand and support sustainable, site-specific irrigation under variable climate conditions. A structured search across major databases yielded 365 articles, of which 92 met the inclusion criteria. Studies were grouped into four categories: remote sensing, agro-meteorology, wireless sensor networks, and integrated approaches. Remote sensing techniques, including multispectral and thermal imaging, enable the spatial monitoring of vegetation indices and stress indicators, such as the Crop Water Stress Index. Agro-meteorological data feed evapotranspiration models using temperature, humidity, wind, and radiation inputs. Wireless sensor networks provide continuous, localized data on soil moisture and canopy temperature. Integrated approaches combine these sources to improve irrigation recommendations. Findings suggest that combining remote sensing, wireless sensor networks, and agro-meteorological inputs can reduce water use by up to 30% without yield loss. Challenges include sensor calibration, data integration complexity, and limited scalability. This review also compares methodologies and highlights future directions, including artificial intelligence systems, digital twins, and affordable Internet of Things platforms for irrigation optimization. Full article

Almond decline and dieback have become significant challenges in newly established orchards, with symptoms including internal necrosis, canker, and external gummosis. This work aims to explore the potential fungal and bacterial causative agents through metabarcoding and traditional culture plate isolation across six almond cultivars. Our results emphasize the multifactorial nature of almond decline and dieback, with possible co-infections by opportunistic fungi and bacteria playing a central role. Classical isolation identified 47 fungal species or genera, including Diaporthe amygdali, Diplodia corticola, Phytophthora sp., and several Fusarium species. Almond metabarcoding revealed a more diverse microbial community, highlighting the prevalence of soilborne pathogens such as Neocosmospora rubicola, Dactylonectria estremocensis, and Plectosphaerella niemeijerarum. Soil metabarcoding suggested that these pathogens likely originate from nursery substrates or soils shared with other crops, such as olives and vineyards, that serve as a source of inoculum. ‘Soleta’ generally presented lower richness when compared to the other tested cultivars, suggesting a higher degree of biotic stress and decreased plant resilience. This study highlights the value of integrating NGS approaches to comprehensively study complex diseases and the need for further research on pathogen interactions and cultivar susceptibility for the future development of new sustainable, targeted management strategies in almond orchards. Full article

Innovative applications of high-resolution airborne imaging are explored for detecting grapevine diseases. Driven by the motivation to enhance early disease detection, the method’s effectiveness lies in its capacity to identify isolated cases of grapevine yellows (Flavescence dorée and Bois Noir) and trunk disease (Esca complex), crucial for preventing the disease from spreading to unaffected areas. Conducted over a 17 ha vineyard in the Forlì municipality in Emilia-Romagna (Italy), the aerial survey utilized a photogrammetric camera capturing centimeter-level resolution images of the whole area in 17 minutes. These images were then processed through an automated analysis leveraging RGB-based spectral indices (Green–Red Vegetation Index—GRVI, Green–Blue Vegetation Index—GBVI, and Blue–Red Vegetation Index—BRVI). The analysis scanned the 1.24 · 10⁹ pixels of the orthomosaic, detecting 0.4% of the vineyard area showing evidence of disease. The instances, density, and incidence maps provide insights into symptoms’ spatial distribution and facilitate precise interventions. High specificity (0.96) and good sensitivity (0.56) emerged from the ground field observation campaign. Statistical analysis revealed a significant edge effect in symptom distribution, with higher disease occurrence near vineyard borders. This pattern, confirmed by spatial autocorrelation and non-parametric tests, likely reflects increased vector activity and environmental stress at the vineyard margins. The presented pilot study not only provides a reliable detection tool for grapevine diseases but also lays the groundwork for an early warning system that, if extended to larger areas, could offer a valuable system to guide on-the-ground monitoring and facilitate strategic decision-making by the authorities. Full article

Among grapevine trunk diseases, Eutypa dieback, caused by the fungus Eutypa lata, is one of the most critical ones, due to its widespread infection in vineyards and the lack of effective treatments. This fungus is a vascular pathogen that enters grapevines through pruning wounds. The infection process is associated with phytotoxic metabolites produced by the fungus, and as such, the identification of new metabolites from different culture conditions and broths could provide valuable insights into the fungus’s enzymatic system and help its control. For the purposes of this study, the OSMAC (one strain, many compounds) approach was applied to investigate the secondary metabolism of E. lata strain 311 isolated from Vitis vinifera plants in Spain. A total of twenty metabolites were isolated, including five reported for the first time from E. lata and four that are newly identified compounds in the literature: eulatagalactoside A, (R)-2-(4′-hydroxy-3′-methylbut-1′-yn-1′-yl)-4-(hydroxymethyl)phenol, (S)-7-hydroxymethyl-3-methyl-2,3-dihydro-1-benzoxepin-3-ol, and (3aR,4S,5R,7aS)-4,5-dihydroxy-6-((R)-3′-methylbuta-1′,3′-dien-1′-ylidene)hexahydrobenzo[d][1,3]dioxol-2-one. These compounds were extracted from fermentation broths using silica gel column chromatography and high-performance liquid chromatography (HPLC). Their structures were elucidated through extensive 1D and 2D NMR spectroscopy, along with high-resolution electrospray ionization mass spectrometry (HRESIMS). Compounds were evaluated for phytotoxicity against Phaseolus vulgaris, with only eulatagalactoside A producing white spots after 48 h. Additionally, the antibacterial activity against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae of selected compounds was tested. The compounds (R)-2-(4′-hydroxy-3′-methylbut-1′-yn-1′-yl)-4-(hydroxymethyl)phenol and (S)-7-(hydroxymethyl)-3-methyl-2,3-dihydrobenzo[b]oxepin-3-ol showed the most significant antimicrobial activity against Gram-positive bacteria, inhibiting S. aureus by over 75%, with IC₅₀ values of 511.4 µg/mL and 617.9 µg/mL, respectively. Full article

The Demarcated Region of Madeira (DRM) is one of the oldest wine regions in Portugal, where the famous Madeira Wine (MW) is produced by spontaneous fermentation using endogenous yeasts. Several studies reported the role of endogenous Saccharomyces cerevisiae strains in the regional identity of wines, but only a few studies have been published in the DRM. The PCR-Interdelta (Polymerase Chain Reaction-Interdelta) analysis is a reliable method for S. cerevisiae strain identification. Here, we report the S. cerevisiae strains isolated from six Vitis vinifera grape varieties, namely, Tinta Negra, Boal, Sercial, Verdelho, Malvasia de São Jorge, and Complexa, which are widely used in MW production. During the 2020 campaign, eleven samples were collected from licensed vineyards and a winery, and submitted to spontaneous microfermentations and yeast isolation. Of the 1452 isolates counted, 1367 (94.2%) presented morphological characteristics of S. cerevisiae. We randomly selected 330 isolates from the positive colonies for strain identification. First, the PCR-Interdelta was optimized in ten commercial strains, using δ2–δ12 and δ12–δ21 pairs of primers, and δ2–δ12 primers were selected to screen the 330 isolates. We detected three fermentative profiles and a total of 25 PCR-Interdelta patterns were obtained, representing 7.6% of intraspecific variability, starting with the first non-official collection. The findings underscore the pivotal role of S. cerevisiae strain diversity in shaping the regional identity and quality of wines, with molecular tools like PCR-Interdelta analysis proving essential for monitoring intraspecific variability. Full article

Bioprotection in winemaking refers to the use of naturally occurring microorganisms—mainly non-Saccharomyces yeasts—to inhibit the growth of spoilage microbes and reduce the need for chemical preservatives like sulfur dioxide (SO₂). Numerous studies have demonstrated the benefits of non-Saccharomyces as bioprotectants. However, the use of Saccharomyces cerevisiae as a bioprotectant has been studied very little. Furthermore, it can offer many advantages for the production of sulfite-free wines. To test if S. cerevisiae could be used in bioprotection, we compared the ability of different strains to inhibit the growth of Brettanomyces bruxellensis and Hanseniaspora uvarum. Among the strains tested, the S. cerevisiae Sc54 strain isolated from the vineyard of the Bekaa plain was selected. To investigate its mechanisms of action, we analyzed its metabolite production, including acetic acid and ethanol. Taking into account the low levels of these metabolites and the lack of similar inhibition patterns in media supplemented with acetic acid and ethanol, it appears that other factors contribute to its antagonistic properties. Nutrient competition was ruled out as a factor, as the growth inhibition of B. bruxellensis and H. uvarum occurred rapidly within the first 24 h of co-culture. In this study, we explored the role of the S. cerevisiae killer toxin (Sc54Kt) as a bioprotective agent against H. uvarum and B. bruxellensis spoilage yeasts. Purification procedures with ethanol allowed the extraction of Sc54Kt, yielding two concentrations (0.185 and 0.5 mg/mL). Remarkably, semi-purified Sc54Kt exhibited inhibitory effects at both concentrations under winemaking conditions, effectively controlling the growth and metabolic activity of the target spoilage yeasts. Overall, these findings demonstrate that S. cerevisiae Sc54 not only exerts a strong bioprotective effect but also contributes to improving the quality of wine. The results suggest that S. cerevisiae Sc54 is a promising bioprotective agent for mitigating spoilage yeasts in winemaking, offering a natural and effective alternative to conventional antimicrobial strategies. Full article

Contamination of agricultural products by Fusarium species is a significant concern and is commonly found in various agricultural products. They cause severe economic losses in the products, and contaminate and threaten human and animal health due to the toxins they produce. Therefore, determining species diversity in various agricultural products is crucial. Bozcaada is well suited for cultivating the highest quality Çavuş grape due to its unique location and climate. Therefore, in this study, the sequencing of the tef1 and tub2 genes in Fusarium isolates from table Çavuş and wine grapes Karalahna, which are specific to Bozcaada, was performed, and their phylogenetic relationships were examined. As a result, it was determined that 11 of the 17 isolates were Fusarium annulatum from the Fusarium fujikuroi species complex (FFSC), 2 were Fusarium nirenbergiae from the Fusarium oxysporum species complex (FOSC), 2 were Fusarium fabacearum from the FOSC, and the last 2 isolates were Fusarium makinsoniae and Fusarium clavus (as ‘clavum’) from the F. incarnatum-equiseti species complex (FIESC). The F. makinsoniae and F. fabacearum species obtained in the study are the first recorded for Türkiye. This research highlights the variety of Fusarium species identified in Bozcaada vineyards in Türkiye. Full article