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…

Mitigation of retronasal smoke flavor carryover in the sensory analysis of smoke affected wines

With the steady rise in wildfire occurrence in wine regions around the world, there are quality issues beginning to face the wine industry. These fires produce clouds of smoke which have the ability to carry organic molecules across vast distances that can be absorbed by grapes. When these compounds make their way into the final wine, unpleasant smokey and burnt flavors are present, along with a lasting ashy finish. Along with the volatile compounds carried by smoke, once incorporated into the fruit these compounds become bound to sugars, forming glycosidic compounds.

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Climate change impact study based on grapevine phenology modelling

In this work we present a joint model of calculation the budbreak and full bloom starting dates which considers the heat sums and allows reliable estimations for five white wine grape varieties

La perception des terroirs du vignoble des Coteaux du Layon

On peut être surpris de l’existence d’un vignoble de vins liquoreux, le vignoble des Coteaux du Layon, dans une zone septentrionale à la limite Nord de la culture de qualité de la vigne et ce d’autant plus que le cépage de ce vignoble, le Chenin ou Pineau de la Loire, est un cépage semi tardif. La première explication est à rechercher au niveau des facteurs naturels (données climatiques et géopédologiques) permettant la réalisation de ce type de produit. Il est nécessaire de souligner ici l’importance de chaque paramètre du terroir pris dans im sens large (géopédologique et climatique) et que toute variation de l’un d’entre eux, même non perceptible en première analyse à l’homme, peut avoir des incidences déterminantes sur la qualité des vins.

High levels of copper and persistent synthetic pesticides in vineyard soils

Downy mildew (Plasmopara viticola), powdery mildew (Erysiphe necator) and bunch rot (Botrytis cinerea) are the most prevalent fungal diseases in viticulture.