terclim by ICS banner
IVES 9 IVES Conference Series 9 Exploring zoxamide sensitivity in Plasmopara viticola populations: implications for fungicide management in precision agriculture

Exploring zoxamide sensitivity in Plasmopara viticola populations: implications for fungicide management in precision agriculture

Abstract

Fungicides play a critical role in managing grapevine downy mildew caused by the oomycete Plasmopara viticola, a biotrophic and polycyclic pathogen with a high risk of fungicide resistance. Zoxamide, categorized as a low to medium resistance risk, disrupts cell division by inhibiting tubulin polymerization. Resistance to zoxamide is uncommon in field isolates. This six-year study (2017-2022) aimed to detect and quantify zoxamide sensitivity in P. viticola populations across varying resistance pressures in Italian grapevine regions. Analysis of 126 samples from 57 vineyards, mainly in North-Eastern Italy, revealed that most samples exhibited EC50, EC95, and MIC values below 0.1 and 10 mg/L of zoxamide, respectively. Nineteen vineyards showed reduced sensitivity (MIC>100 mg/L), but only four samples were characterized by 24-54% resistant oospores at >100 mg/L of zoxamide. Notably, samples treated 4-5 times displayed a broader distribution of toxicological parameters, suggesting a heightened need to manage fungicide applications to reduce selection pressure. In conclusion, oospore assays proved valuable not only for detecting the overall sensitivity profile of populations but also for quantifying resistant individuals within them, enabling a better identification of critical factors affecting zoxamide sensitivity and highlighting the need for improved management practices in a precision agriculture context.

DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Mattia Peracchi1*, Beatrice Lecchi1, Giuliana Maddalena1, Silvia Laura Toffolatti1

1 Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali – DISAA, Via Celoria 2, 20133 Milano2

Contact the author*

Keywords

plant disease, integrated pest management, disease control, fungicide resistance

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Metabolomic profiling of botrytized grape berries: unravelling the dynamic chemical transformations during noble rot

Botrytis cinerea, a fungal pathogen commonly known as grey mold, which under specific climatic conditions can develop into a desirable form known as noble rot. In this process the fungus penetrates the grape skin, allowing water evaporation and concentration of sugars and flavors, while profoundly affects the metabolite composition of grapes, leading to the production of unique and desirable compounds in the resulting wines. The result is a unique and complex wine with a luscious sweetness, heightened aromatics, and a distinct character.

Trials with machine harvested sauvignon blanc: the importance of grape transport time and temperature

It is well known that free varietal thiols, in particular 3-mercaptohexanol (3MH) and 3-mercaptohexyl ace-tate (3MHA), are important constituents to the aroma of New Zealand Sauvignon blanc wines.

Grapevine varietal diversity as mitigation tool for climate change: Agronomic and oenologic potential of 14 foreign varieties grown in Languedoc region (France)

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Approaches to the classification of wine aroma aging potential. Applications to the case of Valpolicella red wines

Unlike most of other foods, wine sensory quality is thought to reach a peak after an aging period. In the case of the Valpolicella red wines

How to develop strategies of adaptation to climate change based on a foresight exercise?

Prospective studies raise a real intellectual interest for those who contribute to them or take cognizance of it. But they are often considered too difficult to operationalize