terclim by ICS banner
IVES 9 IVES Conference Series 9 Oospore germination dynamics and disease forecasting model for a precision management of downy mildew 

Oospore germination dynamics and disease forecasting model for a precision management of downy mildew 

Abstract

Downy mildew, caused by Plasmopara viticola, is the most economically impactful disease affecting grapevines. This polycyclic pathogen triggers both primary and secondary infection cycles, resulting in significant yield losses when effective disease control measures are lacking. Over the winter, the pathogen survives by forming resting structures, the oospores, derived from sexual reproduction, which produce the inoculum for primary infections. To optimize grapevine downy mildew control and obtain the desired levels of production while minimizing chemical inputs, it is crucial to optimize the timeframe for fungicide application. Disease forecasting models are useful to identify the infection risk. However, the prediction of primary infections is still a considerable challenge. A prior investigation revealed that the duration required for oospores to germinate (t) decreases as grapevines become susceptible to P. viticola. This study aimed to integrate oospore germination data with insights from the EPI forecasting model in ten vineyards located in Franciacorta, an important Italian viticultural area. The research was performed from grapevine sprouting (April) until bunch closure (July), over three consecutive years (2021-2023). Disease incidence and severity were assessed in untreated plots. Results indicated a simultaneous reduction in t corresponding to the infection risk signaled by the EPI model. A posteriori assessment highlighted the usefulness of biological data in defining the primary infection timing and the accuracy of the model in predicting the disease epidemics. In conclusion, the adoption of the EPI model integrated with the oospore germination assays significantly contributed to formulating a rational treatment strategy.

DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Giuliana Maddalena, Beatrice Lecchi*, Silvia Laura Toffolatti

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

Contact the author*

Keywords

downy mildew, forecasting model, oospore germination, disease management, infection risk

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Protection of grapevines from red blotch by understanding mechanistic basis of its infection

Currently, grapevine is host to a large number of pathogenic agents, including 65 viruses, five viroids and eight phytoplasmas. Needless to say, these pathogens, especially viruses responsible for several ‘infectious degeneration’ or ‘decline’ cause great distress to wine makers and grape growers, let alone the large economic losses incurred by the wine industry. A recent addition to this wide repertoire of grapevine viruses is a new viral disease known as Red Blotch in viticulture parlance. Its causal organism, Grapevine red blotch associated virus (GRBaV), discovered in 2008 is a newly identified virus of grapevines and a putative member of a new genus within the family Geminiviridae.

Influence of nitrogen source on expression of genes involved in aroma production in Saccharomyces uvarum

Saccharomyces uvarum has interesting properties that can be exploited for the production of fermented beverages. Particularly, the cryotolerance and capacity to produce high amounts of volatile compounds offers new opportunities for the wine industry.

Influence of toasting oak wood on ellagitannin structures

Ellagitannins (ETs) have been reported to be the main phenolic compounds found in oak wood. These compounds, belonging to the hydrolysable tannin class of polyphenols, are esters of hexahydroxydiphenic acid (HHDP) and a polyol, usually glucose or quinic acid. They own their name to their capacity to be hydrolysed and liberate ellagic acid and they have an impact on astringency and bitterness sensation, which is strongly dependant on their structure. The toasting phase is particularly crucial in barrels fabrication and influences wood composition.

Spatial variability of the nutrient distribution in Jerez vineyard soils (Spain)

From a fertility standpoint, the vine has to extract from the soil mineral substances necessary for its existence. However, the amount of certain available nutrients does not always correspond to a proportional increase in quality.

L’effet du climat viticole sur la typicité des vins rouges: caractérisation au niveau des régions viticoles Ibéro-Américaines

Il n’existe presque pas d’études qui caractérisent l’effet du climat viticole sur la typicité des vins en considérant les différents types de climats à l’échelle mondiale. Cette étude fait partie d’un projet CYTED de zonage vitivinicole. L’objectif a été de caractériser l’effet du climat viticole sur la typicité des vins sur une macro région viticole du monde.