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Economic impacts from plant pests are often felt at the regional scale, yet some impacts expand to the global scale through the alignment of a pest's invasion potentials. Such globally invasive species (i.e., paninvasives) are like the human pathogens that cause pandemics. Like pandemics, assessing paninvasion risk for an emerging regional pest is key for stakeholders to take early actions that avoid market disruption. Here, we develop the paninvasion severity assessment framework and use it to assess a rapidly spreading regional U.S. grape pest, the spotted lanternfly planthopper (Lycorma delicatula; SLF), to spread and disrupt the global wine market. We found that SLF invasion potentials are aligned globally because important viticultural regions with suitable environments for SLF establishment also heavily trade with invaded U.S. states. If the U.S. acts as an invasive bridgehead, Italy, France, Spain, and other important wine exporters are likely to experience the next SLF introductions. Risk to the global wine market is high unless stakeholders work to reduce SLF invasion potentials in the U.S. and globally. The spotted lanternfly planthopper poses a global threat as a paninvasive wine grape pest. [ABSTRACT FROM AUTHOR]

Economic impacts from plant pests are often felt at the regional scale, yet some impacts expand to the global scale through the alignment of a pest's invasion potentials. Such globally invasive species (i.e., paninvasives) are like the human pathogens that cause pandemics. Like pandemics, assessing paninvasion risk for an emerging regional pest is key for stakeholders to take early actions that avoid market disruption. Here, we develop the paninvasion severity assessment framework and use it to assess a rapidly spreading regional U.S. grape pest, the spotted lanternfly planthopper (Lycorma delicatula; SLF), to spread and disrupt the global wine market. We found that SLF invasion potentials are aligned globally because important viticultural regions with suitable environments for SLF establishment also heavily trade with invaded U.S. states. If the U.S. acts as an invasive bridgehead, Italy, France, Spain, and other important wine exporters are likely to experience the next SLF introductions. Risk to the global wine market is high unless stakeholders work to reduce SLF invasion potentials in the U.S. and globally. The spotted lanternfly planthopper poses a global threat as a paninvasive wine grape pest. [ABSTRACT FROM AUTHOR]

The effective management of grapevine trunk diseases (GTDs) is an ongoing challenge. Hot water treatment (HWT) is an environmentally friendly and economically viable option; however, the short-term effects of HWT on grapevine (Vitis vinifera L.) health and production are not fully understood. The aim of this study was to compare the effects of HWT on plant growth and fungal community structure in nursery stock until plants were completely established in the field. We assessed eleven graft and three rootstock varieties from four local nurseries in a region of Catalonia (NE Spain) where GTDs are a serious threat. After treatment, the plants were left to grow under field conditions for two growing seasons. Metabarcoding of the ITS region was used to study the mycobiomes of plant graft unions and root collars. We also assessed the influence of plant physiological indicators in community composition. Hot water treatment caused lasting changes in GTD communities in both the root collar and graft union that were not always characterized as a reduction of GTD-related fungi. However, HWT reduced the relative abundance of some serious GTD-associated pathogens such as Cadophora luteo-olivacea in graft tissues, and Phaeomoniella chlamydospora and Neofusicoccum parvum in the root collar. Treatment had the greatest influence on the total and GTD-related fungal communities of Chardonnay and Xarel·lo, respectively. Total community variation was driven by treatment and nursery in rootstocks, whereas HWT most significantly affected the GTD community composition in R-110 rootstock. In conclusion, changes in fungal abundance were species-specific and mostly dependent on the plant tissue type; however, HWT did reduce plant biomass accumulation in the short-term. [ABSTRACT FROM AUTHOR]

Although the fungus Phaeomoniella chlamydospora is the most commonly detected causal agent of Petri disease and esca, two important fungal grapevine trunk diseases, little is known about the dispersal patterns of P. chlamydospora inoculum. In this work, we studied the dispersal of P. chlamydospora airborne inoculum from 2016 to 2018 in two viticultural areas of eastern (Ontinyent) and northern (Logrono) Spain. The vineyards were monitored weekly from November to April using microscope slide traps, and P. chlamydospora was detected and quantified by a specific realtime quantitative (qPCR) method set up in this work. The method was found to be sensitive, and a good correlation was observed between numbers of P. chlamydospora conidia (counted by microscope) and DNA copy numbers (quantified by qPCR). We consistently detected DNA of P. chlamydospora at both locations and in all seasons but in different quantities. In most cases, DNA was first detected in the last half of November, and most of the DNA was detected from December to early April. When rain was used as a predictor of P. chlamydospora DNA detection in traps, false-negative detections were observed, but these involved only 4% of the total. The dispersal pattern of P. chlamydospora DNA over time was best described (R2 = 0.765 and concordance correlation coefficient = 0.870) by a Gompertz equation, with time expressed as hydrothermal time (a physiological time accounting for the effects of temperature and rain). This equation could be used to predict periods with a high risk of dispersal of P. chlamydospora. [ABSTRACT FROM AUTHOR]

Grapevine red blotch-associated virus (GRBaV), the causative agent of red blotch disease, is a member of the genus Grablovirus , in the family Geminiviridae and the first known geminivirus of Vitis spp. Limited information is available on the epidemiology of red blotch disease. A 2-hectare Vitis vinifera cv. ‘Cabernet franc’ vineyard in Napa County, California, USA was selected for monitoring GRBaV spread over a three-year period (2014–2016) based on an initially low disease incidence and an aggregation of symptomatic vines at the edge of the vineyard proximal to a wooded riparian area. The incidence of diseased plants increased by 1–2% annually. Spatial analysis of diseased plants in each year using ordinary runs analysis within rows and Spatial Analysis by Distance IndicEs (SADIE) demonstrated aggregation. Spatiotemporal analysis between consecutive years within the association function of SADIE revealed a strong overall association among all three years ( X = 0.874–0.945). Analysis of epidemic spread fitting a stochastic spatiotemporal model using the Monte Carlo Markov Chain method identified strong evidence for localized (within vineyard) spread. A spatial pattern consisting of a combination of strongly aggregated and randomly isolated symptomatic vines within 8-years post-planting suggested unique epidemic attributes compared to those of other grapevine viruses vectored by mealybugs and soft scales or by dagger nematodes for which typical within-row spread and small-scale autocorrelation are well documented. These findings are consistent with the existence of a new type of vector for a grapevine virus. [ABSTRACT FROM AUTHOR]

The fungus Botrytis cinerea causes severe diseases in many crops. In grapevines, it causes Botrytis bunch rot (BBR), one of the most reported diseases worldwide. It affects all herbaceous organs of the vine, especially the ripe berries, causing significant reductions in yield and wine quality. Botrytis detection models traditionally focus on temporal analysis at a specific spatial location, ignoring the study of the spatial variability of the crop. Unmanned aerial vehicles (UAVs) equipped with multispectral cameras can provide high-resolution images that can be valuable information to develop a tool for aerial pest detection. This paper proposes an algorithm to assess the risk of Botrytis development in a vineyard in Spain, using as input products generated by UAV imagery: DTM (Digital Terrain Model), NDVI (Normalised Difference Vegetation Index), CHM (Canopy Height Model) and LAI (Leaf Area Index). They represent the height and architecture of the canopy, the topography and the plant status. Healthy vines were significantly different from vines affected by Botrytis (p < 0.05) in each of these variables, supporting the consistency of using these inputs for the model. This methodology combines photogrammetric, spatial analysis techniques, and machine learning classification methods with deep vineyard-related agronomic knowledge to produce heatmaps with acceptable accuracy (R² > 0.7) that may support vineyard managers in understanding the spatial variability of the disease, allowing the spatial 2D visualisation of the risk of BBR disease development and, potentially, resulting in higher operational efficiency and reducing phytosanitary treatments, as well as economic costs. Furthermore, the present work takes advantage of imaging technologies that provide information about any location in the field, not only about specific points in the vineyard, suggesting that UAV imagery is appropriate to measure the likelihood of BBR development within the vineyard, highlighting the importance of efficient disease management based on spatial variability. • Multispectral imagery was employed to classify the vineyard in several botrytis risk zones. • It uses as input products generated by UAV imagery: DTM, NDVI, CHM and LAI. • Inputs represent the height and architecture of the canopy, the topography and the plant status. • Heatmaps may support vineyard managers in understanding the spatial variability of the disease. • The methodology provides information about any location in the field, not only about specific points. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to investigate whether grapevine variety and must characteristics influence the diversity of Saccharomyces strains and their prevalence during spontaneous fermentations. Methods and results: Musts from different grapevine varieties, all of them autochthonous from Galicia, were used to perform spontaneous fermentations. Yeasts were isolated from the must and at the beginning, in the middle and at the end of fermentations. Those yeasts identified as Saccharomyces were characterized at the strain level by analysis of mtDNA-RFLP. The results showed a low diversity of Saccharomyces strains, which was related to must sugar content and total acidity. Moreover, from a total of 44 different Saccharomyces strains, only eleven of them appeared at frequencies higher than 20% and were able to lead fermentations. A significant correlation between yeast strains and must acidity was observed, with the predominance of certain strains at high acidity values. Conclusions: Must characteristics, such as sugar content and acidity, influence the Saccharomyces strains diversity and the leader strains during fermentation. Significance and Impact of the Study: These results showed the adaptation of certain Saccharomyces strains to must with specific characteristics; this may be considered by winemakers for yeast inocula selection. Our findings have special relevance because this is the first study carried out in Galicia dealing with the influence of must properties on yeast strains that control fermentations. [ABSTRACT FROM AUTHOR]

The female of a new species, Typhlodromus (Anthoseius) atoosae n. sp. collected from a grapevine in Cataluna, Spain is described and illustrated. The species of Amblyseius bryophilus Karg, A. filixis Karg, Aristadromips masseei (Nesbitt), T. (A.) kerkirae Swirski & Ragusa, Typhlodromina conspicua (Garman) represent new distribution records for France and Typhloseiulus simplex (Chant) is a new distribution record for Spain. The measurements and illustrations of these new records are given. Re-description of A. meridionalis Berlese and new morphological data on T. (A.) rhenanoides Athias-Henriot collected in France are also given. [ABSTRACT FROM AUTHOR]

Fifty-eight Cadophora luteo-olivacea and three C. melinii isolates were recovered from grapevines showing black vascular streaking and decline symptoms characteristic of Petri disease, and from different stages of the grapevine nursery process in Spain. The isolates were studied by means of phenotypical characterization, DNA analysis and pathogenicity tests. The morphological characters studied included conidiophore, phialide and conidial morphology. Colony characters and pigment production on MEA, PDA and OA were also examined. Phenotypical data were subjected to cluster analysis, which clearly separated C. luteo-olivacea isolates into four groups. Mating tests were performed on all possible combinations for each Cadophora species but no sexual fruiting bodies were produced. Partial sequences of the nuclear ribosomal internal transcribed spacer (ITS), beta-tubulin (BT) and the elongation factor 1α (EF) were analysed, but no genetic variation occurred within the C. luteo-olivacea isolates or within the C. melinii isolates in any of the regions studied. Pathogenicity tests were conducted on 1-year-old grapevine cuttings of four different rootstocks using four C. luteo-olivacea isolates and one isolate of C. melinii. All Cadophora isolates except the C. melinii isolate caused significantly longer lesions in the xylem of grapevine rootstocks than in the controls. [ABSTRACT FROM AUTHOR]