Lobesia botrana (Lepidoptera: Tortricidae) is a crucial grapevine pest worldwide. Expanding the available biocontrol agents can provide new management strategies compatible with organic viticulture. ...Entomopathogenic nematode (EPN) potential as a biocontrol agent was demonstrated against various developmental stages of L. botrana. For its field application, we hypothesised that by selecting the best combination of EPN-adjuvant and identifying the best area/timing for their application, we will secure their effective implementation against L. botrana. The aim of this study was to determine the best ecological scenarios for their use against L. botrana. We investigate three EPN species naturally occurring in Riojan vineyards: Steinernema feltiae, S. carpocapsae, and Heterorhabditis bacteriophora. We evaluated (i) EPN viability, infectivity, and adherence on leaves combined with adjuvants (Multi-Us, Maximix, Dash HC, Nu-Film-17, and Adrex), (ii) EPN biocontrol against L. botrana larva on leaves and grapes and damage reduction, and (iii) EPN efficacy against L. botrana at 22°, 15°, and 10 °C. Overall, all the adjuvants were compatible with the EPN, except Adrex with Heterorhabditis bacteriophora. Compared with the no application, EPNs (steinernematids) alone or with Maximix increased L.botrana L3 mortality on grapes and leaves, thereby reducing the damage. Pupal mortality caused by steinernematids EPN (alone or with Maximix) decreased with temperature, from ∼60% at 22 °C to <30% at 10 °C. Overall, steinernematids EPN (alone or with Maximix) applied against L. botrana on leaves, grapes, or trunks reduced the damage and increased insect mortality. This study suggests the best-case scenario for the application of EPNs is at sunset during late spring/early autumn at mid-temperatures (22 °C-15 °C). Further field validation is necessary for their full implementation.
•Entomopathogenic nematodes (EPNs) are good biocontrol against Lobesia botrana.•EPNs combined with authorized adjuvants in vineyards are viable and infectious.•EPNs protected leaves and grapes from L. botrana attack and reduced damage.•EPNs controlled pupa when hiding in the grape trunk for overwintering time.•EPNs best performance against L. botrana was at mild temperatures.
•Hyperspectral imaging can identify grapevine leafroll disease (GLD) in vineyards.•Detection sensitivity averaged 94.1%, and ranged from 88% to 99% per vineyard.•Various vineyard-specific factors ...appear to compromise detection sensitivity.•Hyperspectral imaging can be an automatable and repeatable approach to mapping GLD.
Grapevine leafroll disease (GLD) is considered to be one of the most economically destructive viral diseases of grapevines worldwide, resulting in reduced vine vigor, yield reductions, and poor fruit quality. Five pathogens (grapevine leafroll-associated viruses) are recognized as causal agents of this disease, of which Grapevine leafroll-associated virus 3 (GLRaV-3) is the most common. Although there is no cure for the disease, management strategies (including vigilant removal of infected vines) can drastically limit its spread and economic impact. Comprehensive mapping (total population sampling) of disease presence on the ground is cumbersome and cost prohibitive in many situations. In addition, the practice of identifying diseased vines requires individuals to be highly trained to recognize symptoms. Compared to more traditional detection methods, airborne hyperspectral imaging offers a potentially valuable alternative for monitoring the disease that is cost effective, reliable and automatable. This study tests the use of hyperspectral imaging to aid in the management of GLD.
Over the span of two years we monitored five Cabernet Sauvignon vineyards: ground surveys recorded the incidence of visual symptoms of disease in the field during the same months in which hyperspectral maps recorded disease incidence from the air. A customized Geographic Information System (GIS) methodology was developed to compare the visual symptoms to the results of the hyperspectral imaging technique. For a select number of vines, disease incidence was then confirmed by laboratory assays. On average, detection sensitivity was 94.1%, with a range of 88% to greater than 99% per vineyard. Various vineyard-specific factors appear to compromise detection sensitivity. Overall, our results show that remote hyperspectral imaging of GLRaV-3 infected Cabernet Sauvignon vineyards can be a useful and cost-effective approach to mapping diseased vines. Future studies should focus on the use of this tool for detecting GLRaV-3 in other grape varieties, as well as other grapevine pathogens.
The starting point for every viticultural and wine-producing country with respect to local grapevine varieties is their identification, inventory, preservation and development of genetic resources of ...those varieties. There are currently 224 grapevine va?rieties cultivated in Serbia for the purpose of commercial production of grapes and wine. Out of that number, 31 wine varieties are local. Vineyards under those varieties can be dif?ferentiated by their importance for production of grapes and wine, and by the level of their endangerment, that is, sustainability in conditions caused by climate changes. This paper presents the creation, that is, the modeling of the Method for Vineyard Sustainability Clas?wine grapevine varieties on grounds of their endangerment and sustainability, based on 20 examined and categorized individual vineyard sustainability parameters; to carry out comsification (MVSC). The purpose of MVSC classification is: to valorize vineyards with local prehensive classification into one of the four established vineyard sustainability classes (Class A - very endangered vineyards, Class B - endangered vineyards, Class C - sustainable vineyards and Class D - very sustainable vineyards); spatial identification and presentation of vineyards based on determined vineyard sustainability class through application of GIS technology; and finally, application of Network Analysis (NA), prioritization of examined parameters and, therefore, vineyards. A total of 10,402 vineyards under local grapevine wine varieties were used for modeling, and it was determined that 29 vineyards with the total surface of 1.2 hectares should be classified in Class A, while 2,883 vineyards with the total surface of 158.2 hectares should be classified in Class B. With respect to the strength of 20 individual vineyard sustainability parameters, it was determined that the parameter Structure of the vine rootstock (SVR) has the greatest impact, and priority in selection of vineyards in different sustainability classes should be given to vineyards without rootstocks. In accordance with the scientific justification of obtained results, the MVSC enables comprehensive clas?sification of the potential for sustainability of genetic resources of local grapevine varieties in Serbia, and it can be applied in other countries and wine-growing areas, as well as to other groups of grapevine varieties.
The soil microbiome is linked to the microbial ecosystem of aboveground plant tissues and it is able to modulate and stimulate plant responses. The community composition, i.e. diversity and ...abundance, is influenced by several factors such as agronomical practices, agrochemical practices and geographical location. For the first time, we present here the investigation of the microbial community related to the soil of a long-established cultivated vineyard using the meta-barcoding approach. Specifically, we analyzed the bacterial and fungal communities of the bulk soils associated with esca-symptomatic and asymptomatic vines. Results showed no significant differences in richness between the two types of samples. Conversely, we observed that esca-related pathogens and grapevine trunk disease (GTD) pathogens were more abundant in the bulk soils of symptomatic plants, suggesting that the soil could represent an important source of inoculum. We also identified two fungal genera, Curvularia and Coprinopsis, which are exclusive to the soil associated with asymptomatic plants. Moreover, Actinobacteria, a well-known group of bacteria symbionts, are over-represented in asymptomatic soils. Further studies are needed to expand the knowledge about these microorganisms, since they could have a role in controlling the development and/or spread of esca pathogens.
•First description of microbial ecosystem in bulk soil of an ESCA diseased vineyard.•ESCA-related pathogens in bulk soil could represent a major source of fungal pathogens.•Both bacterial and fungal community are affected by accumulation of ESCA pathogens.
Vitis and non-Vitis spp. surrounding nine Napa Valley vineyards were surveyed for Grapevine leafroll-associated virus (GLRaV)-1 to -5 and -9, Grapevine virus A (GVA), Grapevine virus B (GVB), and ...Grapevine virus D (GVD). Vitis spp. from three riparian areas not adjacent to vineyards were also included. DNA fingerprinting and probability analyses indicated that the Vitis samples consisted primarily of Vitis californica followed by V. californica × V. vinifera hybrids. Single and mixed infections of GLRaV-2, -3, GVA, or GVB were detected by conventional or quantitative reverse-transcription polymerase chain reaction in 6 of the 66 V. californica and 11 of the 19 V. californica × V. vinifera hybrids. GLRaV-1, -4, -5, -9, and GVD were not detected. Phylogenetic analysis of GLRaV-2 and -3 partial coat protein gene nucleotide sequences indicated that the isolates from V. californica and V. californica × V. vinifera hybrids were closely related to isolates from V. vinifera.
Abstract
Aim
This study evaluates the in vitro efficacy of 8-hydroxyquinoline (8HQ) derivatives in controlling the phytopathogenic fungus Phaeomoniella chlamydospora.
Methods and results
The in vitro ...tests assessed the susceptibility to the minimum inhibitory concentration (MIC), checkerboard assay, mycelial growth (MG) inhibition, and EC50 determination. Among the seven agricultural fungicides tested, tebuconazole (TEB) displayed the lowest MIC, 1.01 µg mL−1, followed by captan (CAP), thiophanate methyl (TM), and mancozeb with MICs of 4.06, 5.46, and 10.62 µg mL−1, respectively. The 8HQ derivatives used in this study were clioquinol and PH 151 (PH) with MICs of 1.09 and 2.02 µg mL−1, respectively. PH associated with TEB and CAP showed synergism and inhibited 95.8% of MG at the highest dose. TEB inhibited 100% of MG at the three highest doses, while associated with PH exhibited the lowest EC50 (0.863 + 0.0381 µg mL−1).
Conclusions
We concluded that the 8HQ derivatives tested controlled effectively the P. chlamydospora in vitro. PH associated with CAP and TEB exhibited a synergistic effect. The association between PH and TM was considered indifferent.
Impact Statement
This study expands the list of active ingredients tested against P. chlamydospora, with the PH 151 and clioquinol derivatives being tested for the first time. The in vitro efficacy and synergistic action with other fungicides suggest a potential use as a grapevine wound protectant. This association makes it possible to reduce doses and increase the potency of both drugs, reducing the risk of resistance development and harm to humans and the environment.
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